10th International "Hiroshima" Symposium on the Development and Application of Semiconductor Tracking Detectors, Xi'an, China

25 Sept 2015, 16:00 → 29 Sept 2015, 20:00 PRC

International Conference Center (also named as <a href="http://www.jdnyhotel.com/index.php" target="_blank">“Nanyang Hotel”</a>)

Xinchou Lou (University of Texas at Dallas (US))

Submission closure: Dec. 31

First of all, we appreciate those who have submitted the manuscripts. We have submissions of about 60 papers as of 10th Dec. These papers are in the pipeline of reviewing now. It would take some time since we are requesting two reviews per paper. We appreciate your help being a peer-reviewer when you are asked to. Once accepted for publication, the papers will be online, accessible through DOI numbers, well before the printing of the proceedings issue.

After two months since the original deadline of 6th Nov., we will close the submission of the manuscripts at the end of year, 31st Dec. We urge those of you who have been writing but have not been able to submit yet to submit by the submission closure date. ...from HSTD10 editors

The Elsevier Editorial System (EES) is open for article submission. The instructions for submission are as follows: The submission website for this journal is located at:

http://ees.elsevier.com/nima_proceedings/

Log-in as a "Author", then click "Submit paper" in the menu below the "NIMA PROCEEDINGS" banner. To ensure that all manuscripts are correctly identified for inclusion into the special issue, it is important that authors select

“SI: NIMA_ HSTD-10”

when the “Article Type” step in the submission process is reached. 

...more info in Paper submission

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The primary goal of this symposium is to bring together experts in the design, processing and applications of semiconductor tracking detectors for discussions of past experiences, lessons learned and new ideas which are still in the early stage of development.

Key dates:

June 10   Abstract submission open
June 10   Registration open
July 31   Abstract submission closure
July 31   Early Registration end
September 3   Symposium Registration end
September 26 - 29   Symposium sessions
November 6 - Submission of NIMA paper manuscript

1st circular HSTD10_1st_circular_V1.2.5.pdf

Announcement HSTD10_Announcement.pdf

Final circular HSTD10_final_circular_V1.0.3.pdf TaxiInstruction.png

Poster poster-update-v3.jpg

Symposium photos hstd10photo.png

Friday, 25 September

19:00 → 21:00 Reception and Registration/Payment

Saturday, 26 September

08:00 → 08:30 Registration: Registration desk opens till 12:00

08:30 → 09:10 Opening of the Symposium

Convener: Prof. Baowen Yang (Dean, School of Nuclear Science and Technology)

08:30 Welcome address

Speaker: Li Liang (Director, Division of International Communication,XJTU)

08:40 Opening Address

Speaker: Yoshinobu Unno (High Energy Accelerator Research Organization (JP))

OpeningAddress150926_R0.pdf

OpeningAddress150926_R0.pptx

08:50 Taking Sysmposium Photo

Speaker: Qingmin Zhang (XJTU)

Symposium photos

09:10 → 12:30 Simulations & Manufacturing

Conveners: Hartmut Sadrozinski (SCIPP, UC santa Cruz), Marko Mikuz (Jozef Stefan Institute (SI))

09:10 LHC Upgrade Program of Accelerators and Experiments

TBD

Speaker: Stephen Mcmahon (STFC - Rutherford Appleton Lab. (GB))

SteveHiroshima2015-Talk.pdf

09:40 History and Current Status of Hamamatsu Si detectors

We have been developing various types of SSDs (Silicon Strip Detectors). Hamamatsu SSDs has been used as tracking detector in many collider experiments [CELPHI, CDF, ZEUS, ATLAS, CMS, BELLE, etc.] and space experiments [ FGST(GLAST), AGILE, etc.]. For LHC, we have developed SSD which have high radiation tolerance and good quality of low bad channel rate. We delivered 15,500 SSDs to ATLAS from 1999 to 2002 year and delivered 24,000 pieces of SSDs to CMS from 2002 to 2005 year. In addition, 140000pcs of Hamamatsu APDs (Avalanche Photo Diodes) are also used as photo detector of PWO4 scintillator in the CMS electromagnetic calorimeter. These APDs have high blue sensitivity and low noise characteristics. The MPPC (Multi-Pixel Photon Counter, Hamamatsu trade mark) is a solid state device made up of multiple APD pixels operated in Geiger mode. MPPC is well matched to detect the week emission light of scintillators for High Energy Physics or medical applications. For example, T2K experiment adopted MPPCs and is using 60,000 pieces of 1.3x1.3mm-MPPCs. MPPC will be expected and evaluated for Cherenkov light detection. We are continuing to develop Si detectors for next experiments like HL-LHC (High Luminosity-LHC) that requires enhanced radiation hardness of 5 times or more.

Speaker: Kazuhisa Yamamura (Hamamatsu Photonics K.K.)

Yamamura_manuscript_HSTD10.pdf

10:10 Atomic Layer Deposition (ALD) grown thin films for ultra-fine pitch pixel detectors

In particle physics applications, the innermost pixel detectors will face in the future unprecedented requirements. Due to the increasing luminosity, the charge collection distance will be degraded to be less than physical segmentation of existing pixel devices resulting in poor particle tracking performance. Obvious approach to maintain sufficiently good spatial resolution is to increase the granularity of tracking detectors, i.e. downscaling the pixel size. Presumably, implementation of p-stop and/or p-spray structures, needed in radiation hard n on p pixel devices, will become challenging. Furthermore, in case of DC-coupled pixel sensor design, integrated bias resistors are required for quality assurance by IV-probing of a sensor prior valuable Flip-Chip bonding and module assembly processes. As a consequence of the small pixel size, the realization of traditional punch-through biasing becomes very difficult. ALD is known as a method producing pinhole-free thin films due to it's self-limiting surface chemistry growth mechanism. It is possible with ALD to engineer oxide and interface charge type and density at dielectric-silicon interfaces enabling surface current termination in n on p detectors by negative oxide charge. We have studied the use of ALD thin films as resistor material for the future pixel sensor applications. We will present the results of Titanium nitride (TiN) thin films grown by plasma enhanced atomic layer deposition (PEALD). In very high luminosity environment, it would be favorable to isolate capacitively the DC leakage current from the input of the readout ASIC. In this contribution, we will discuss the approach to use ALD grown dielectric films as capacitive coupling (AC-coupling) layers due to their potentially high capacitance density.

Speaker: Jaakko Harkonen (Helsinki Institute of Physics)

10:30 The MAPS-based vertex detector for the STAR Experiment: lessons learned and performance

The PiXeL detector (PXL) of the STAR experiment at RHIC is the first application of the state-of-the-art thin Monolithic Active Pixel Sensors (MAPS) technology in a collider environment. The PXL, together with the Intermediate Silicon Tracker (IST) and the Silicon Strip Detector (SSD), form the Heavy Flavor Tracker (HFT), which has been designed to improve the vertex resolution and extend the STAR measurement capabilities in the heavy flavor domain, providing a clean probe for studying the Quark-Gluon Plasma. The two PXL layers are placed at a radius of 2.8 and 8 cm from the beam line, respectively, and accommodate 400 ultra-thin (50 μm) high resolution MAPS sensors arranged in 10-sensor ladders to cover a total silicon area of 0.16 m$^2$. Each sensor includes an array of nearly 1 million pixels with a pitch of 20.7 μm. The sensor features 185.6 μs readout time and 170 mW/cm$^2$ power dissipation. The detector is air-cooled, allowing a global material budget of 0.4% radiation length on the innermost layer. A novel mechanical approach to detector insertion allows for the installation and integration of the pixel sub detector within a 12 hour period during an on-going STAR run. The detector was successfully commissioned and took data in Au+Au collisions at 200 GeV during the 2014 RHIC run. With improved reliability, material budget, and tracking capabilities, the HFT took data in p+p, p+Au, and p+Al collisions at $\sqrt{s_{NN}}=$200 GeV in the 2015 RHIC run. In this talk we will present detector specifications, experience from the construction and operations, and lessons learned. We will also show preliminary results from 2014 Au+Au data analyses, demonstrating the capabilities of charm reconstruction with the HFT.

Speaker: Giacomo Contin (Lawrence Berkeley National Lab. (US))

HFT_Hiroshima_Symp_GContin_1.pdf

10:50 Coffee break

11:20 Silicon Based Direct Annihilation Detectors

The AEgIS experiment, at the CERN Antiproton Decelerator, aims at measuring the gravitational fall of antihydrogen using a cold, pulsed antihydrogen beam. In the last year a symbiotic antiproton beamline has been commissioned for performing detector tests with low energy antiproton beams. We will present here the latest results obtained on this beamline employing a Timepix3 hybrid module. The detector space and time resolution make it particularly suited to detection of antimatter annihilation events. Montecarlo simulations will complement the presented results, hinting at future developments for the AEgIS silicon position sensitive detector.

Speaker: Nicola Pacifico (University of Bergen (NO))

Pacifico_Hiroshima_2015.pdf

11:40 Ultra-Fast Silicon Detectors

We report on the status and expectation of the development of Ultra-Fast Silicon Detectors (UFSD). UFSD are novel silicon sensors based on the Low-Gain Avalanche Diodes (LGAD) design and, due to internal gain, exhibit a signal which is a factor of ~ 10 larger than standard silicon detectors. The internal gain allows obtaining fast and large signals, a pre-requisite for time applications, and thus they are poised to extend the use of silicon sensors characterized by excellent position resolution into the precision time domain. UFSD with the desired gain are being manufactured routinely in a variety of sizes. Their time resolution has been measured both in beam tests with electrons and pions and with laser pulses. An important parameter for the time resolution is the “slew-rate” dV/dt which depends on the internal gain in addition to the charge collection time (i.e. the detector thickness) and the capacitance. The timing measurements compare well with the prediction of the simulation program Weightfield 2, and we extend the prediction of the performance to future applications in both particle physics and medical physics.

Speaker: Hartmut Sadrozinski (University of California,Santa Cruz (US))

UFSD HSTD10-Talk.pdf

UFSD HSTD10-Talk.pptx

12:10 Recent developments on LGAD and iLGAD detectors for tracking and timing applications

The objective of this work is the development of new position sensitive detectors with low signal amplification useful also for timing applications and called Low Gain Avalanche Detector (LGAD). These new devices are based on the standard Avalanche Photo Diodes (APD) normally used for optical and X-ray detection applications. We will present the two dimensional numerical simulation based on Sentaurus and Silvaco simulation tools and the technological steps needed for the fabrication. In this talk we will present two different approaches for the fabrication of these devices. First a single side n-on-p detector that collect and amplify electrons and second a double sided p-on-p detector that collects holes and amplify electrons. Silicon pads, microstrip and pixelated sensors have been fabricated at the clean room facility of the Centro Nacional de Microelectronica in Barcelona with a small signal gain in order to reduce their thickness without reducing the charge collected signal amplitude keeping the same signal to noise ratio. This allows using the standard readout front-end electronics without signal saturation. This work was developed in the framework of the CERN Rd50 collaboration and the investigation carried out on these detectors provides important indications on the ability of such modified electrode geometry to control and optimize the charge multiplication effect, in order to fully recover the collection efficiency of heavily irradiated silicon detectors.

Speaker: Giulio Pellegrini (Centro Nacional de Microelectrónica (IMB-CNM-CSIC) (ES))

Hiroshima_pellegrini_2.pdf

12:30 → 14:00 Lunch break

14:00 → 17:10 Pixels (including CCD's)-1

Conveners: Giovanni Calderini (Centre National de la Recherche Scientifique (FR)), Ingrid-Maria Gregor (DESY)

14:00 The upgraded Pixel Detector of the ATLAS Experiment for Run2 at the Large Hadron Collider

Run-2 of the LHC will provide new challenges to track and vertex reconstruction with higher energies, denser jets and higher rates. Therefore the ATLAS experiment has constructed the first 4-layer Pixel detector in HEP, installing a new Pixel layer, also called Insertable B-Layer (IBL). IBL is a fourth layer of pixel detectors, and has been installed in May 2014 at a radius of 3.3 cm between the existing Pixel Detector and a new smaller radius beam-pipe. To cope with the high radiation and pixel occupancy due to the proximity to the interaction point, two different silicon sensor technologies (planar and 3D) have been developed as well as a new read-out chip within CMOS 130nm technology and with larger area, smaller pixel size and faster readout capability. The new detector is the first large scale application of of 3D detectors and CMOS 130nm technology. An overview of the lessons learned during the IBL project will be presented, focusing on the challenges and highlighting the issues met during the production, integration, installation and commissioning phases of the detector.

Speaker: Malte Backhaus (CERN)

Hiroshima2015-Backhaus.pdf

14:20 Status of the CMS Phase I Pixel Detector Upgrade

Based on the strong performance of the LHC accelerator, it is anticipated that peak luminosities of two times the design luminosity of L = 2 x10^34 cm^-2s^-1 are likely to be reached before 2018 and probably significantly exceeded in the so-called Phase I period until 2022. At this higher luminosity and increased hit occupancies the current CMS pixel detector would be subject to severe dead time and inefficiencies introduced by limited buffers in the analog read-out chip and effects of radiation damage in the sensors. Therefore a new pixel detector is being built and will replace the current detector in the extended year-end technical stop in 2016. The new CMS pixel detector features four central barrel layers and three end-cap disks in forward and backward direction for robust tracking performance, and a significantly reduced overall material budget including new cooling and powering schemes. The design of the new front-end readout chip comprises larger data buffers, an increased transmission bandwidth, and low-threshold comparators. These improvements allow the new pixel detector to sustain and improve the efficiency of the current pixel tracker at the increased requirements imposed by high luminosities and pile-up. This contribution gives an overview of the design of the new pixel detector and the status of the upgrade project, and presents performance measurements of the production read-out chip and final detector modules.

Speaker: Simon Spannagel (Deutsches Elektronen-Synchrotron (DE))

hiroshima-spannagel.pdf

14:40 Radiation Hard Pixel Development for the LHCb VELO Upgrade

The upgrade of the LHCb experiment, planned for 2018, will transform the experiment to a trigger-less system reading out the full detector at 40~MHz event rate. All data reduction algorithms will be executed in a high-level software farm with access to the complete event information. This will enable the detector to run at luminosities of $\mathrm{2 \times 10^{33} cm^{-2} s^{-1}}$ and probe physics beyond the Standard Model in the heavy flavour sector with unprecedented precision. The Vertex Locator (VELO) is the silicon vertex detector surrounding the interaction region. The current detector will be replaced with a hybrid pixel system equipped with electronics capable of reading out at 40~MHz, designed to withstand the irradiation expected at an integrated luminosity of 50 $\mathrm{fb^{-1}}$ and beyond. The detector will be composed of silicon pixel sensors with $\mathrm{55 \times 55~\mu m^{2}}$ pitch, read out by the VeloPix ASIC which is being developed based on the TimePix/MediPix family. The hottest region will have pixel hit rates of 900 Mhits/s yielding a total data rate more than 3 Tbit/s for the upgraded VELO. The sensors, manufactured by two different vendors and with a variety of guard ring and implant designs, have been irradiated in 5 different facilities, with both neutrons and protons, uniformly and non-uniformly. The performance post irradiation has been measured in testbeam and lab. In addition the radiation hardness of parylene coating has been investigated. The efficiency has been probed in detail within the pixel cell and a comparison made of different implant sizes, showing a difference in efficiency in the pixel corners after irradiation. The charge collection of thin and thick sensors has been compared after the full irradiation. In addition the Timepix3 has been used to investigate the time response of the sensors at a variety of angles, and also to check the regions of increased current after irradiation. The results of this sensor testing campaign, the first time that the small pixel performance after heavy irradiation has been measured, will be presented.

Speaker: Xabier Cid Vidal (CERN)

LHCb_VELO_Upgrade_Hiroshima_Symposium_XabierCid.pdf

15:00 The Belle-II Silicon Vertex Detector

The Belle II experiment at the SuperKEKB collider in Japan is designed to indirectly probe new physics using approximately 50 times the data recorded by its predecessor (Belle). An accurate determination of the decay-point position of subatomic particles such as beauty and charm mesons as well as a precise measurement of low-momentum charged particles will play a key role in this pursuit. These will be accomplished by a vertex detector, which comprises two layers of pixelated silicon detector (PXD) and four layers of silicon vertex detector (SVD). We describe herein the design, prototyping and construction efforts of the Belle-II SVD, which is aimed to be commissioned towards early 2017.

Speaker: Mr Kameswara Rao Kodali (Tata Institute of Fundamental Research)

Belle II - SVD - Xian.pdf

Belle II - SVD - Xian.pptx

15:20 Tea break

15:50 The Belle II DEPFET Pixel Detector

BELLE II is an experiment in KEK (Tsukuba, Japan ) that will explore heavy flavour physics ( B, charm and tau ) from early 2018 with unprecedented precision. Charged particles are tracked by a two-layer DEPFET pixel device ( PXD ), a four-layer silicon strip detector ( SVD ) and the central drift chamber ( CDC ). The PXD will consist of two layers at radii of 14 mm and 22 mm with 8 and 12 modules respectively. The pixel sizes will vary, between 50µm x (55 – 60)μm in the first layer and between 50µm x (70 – 85)μm in the second layer, to optimize the charge sharing efficiency. These innermost layers have to cope with high background occupancy, high radiation and must have minimal material to reduce multiple scattering. These challenges are met using the DEPFET technology. Each pixel is a FET integrated on a fully depleted silicon bulk. The signal charge collected in the ‘internal gate’ modulates the FET current resulting in a first stage amplification and therefore very low noise. This allows very thin sensors (75 µm) reducing the overall material budget of the detector (0.21% X0). Four fold multiplexing of the column parallel readout allows read out a full frame of the pixel matrix in only 20µs while keeping the power consumption low enough for air cooling. Only the active electronic outside the detector acceptance has to be cooled actively with a two phase CO2 system. Furthermore the DEPFET technology offers the unique feature of an electronic shutter which allows the detector to operate efficiently in the continuous injection mode of superKEKB. All of these features, the sensor concept and the electronics involved, system tests and the construction status will be presented in detail.

Speaker: Hans-Guenther Moser (MPI fuer Physik)

The Belle II DEPFET Pixel Detector.pdf

The Belle II DEPFET Pixel Detector.pptx

The Belle II DEPFET Pixel Detector.pptx

16:10 Active pixel sensors in ams H18/H35 HV-CMOS technology for the ATLAS HL-LHC upgrade

Deep submicron HV-CMOS processes offer the opportunity for sensors built by industry standard techniques while being HV tolerant, making them good candidates for drift-based, fast collecting, thus radiation-hard pixel detectors. We are investigating active pixel sensors, implementing amplifier and discriminator stages directly in insulating deep n-wells, which also act as collecting electrodes. The deep n-wells allow for bias voltages to up to $150\,$V leading to a depletion depth of several $10\,\mu m$ after irradiation. Several prototype sensors in the ams H18 180nm and H35 350nm HV-CMOS processes have been manufactured, acting as a potential drop-in replacement for the current ATLAS Pixel sensors, thus leaving higher level processing such as trigger handling to dedicated read-out chips. Sensors were thoroughly tested in lab measurements as well as in testbeam experiments. Irradiations with X-rays and protons revealed a tolerance to ionizing doses of over $1\,$GRad. A depletion zone of around $15\,\mu m$ was deduced from Sr-90 measurements, which grows to up to about $100\,\mu m$ after irradiation according to Edge-TCT studies. This is attributed to an acceptor removal effect, eventually resulting in a higher collected charge, which partly counteracts trapping effects. Sensors showed high detection efficiencies after neutron irradiation to $10^{15}n_{eq}cm^{-2}$ during testbeam experiments last year, while new testbeam measurements will yield results for sensors at high bias voltages and new prototypes with timewalk compensating discriminators. Also prototypes in ams H35 technology with a simplified circuit are studied. A full size demonstrator chip, implemented in the H35 process is being submitted. Radiation hardness is expected to be comparable to the current sensors, while the timing behavior will be improved by new discriminator designs. Measurement and test results as well as the current status of the project including the demonstrator design will be presented.

Speaker: Branislav Ristic (CERN/Universite de Geneve (CH))

HSDT10_bristic_ams_hvcmos_sensors.pdf

16:30 CMOS pixel sensors on high resistive substrate for high-rate, high-radiation environments

The design of fast, rad-hard pixel detectors for future HEP experiments requires drift-based sensor concepts. To achieve this, high resistive bulk material and/or the possibility to apply high voltage to bias the sensor are needed. Commercial CMOS technologies on high resistive substrate are becoming an interesting option for this kind of development. In addition to the possibility of having a depleted volume for charge collection, they provide a comparatively cheap process with high throughput suitable for future large area detectors. Production on 8” wafers allows for wafer scale hybridization processes, without the need of laborious and expensive bump bonding. Both passive and active sensors can be designed. We will present results on prototype pixel matrices in the LFoundry 150nm CMOS process on a 2kOhm-cm p-type bulk material. Two flavors of active CMOS pixels have been designed, as well as a passive sensor and test structures. Characterization is ongoing both in the lab and in test beams. The sensors show leakage current lower than a few nA per unit volume and breakdown voltage around 120V, before irradiation. Depletion depth is measured to be approximately 120um for bias voltages of 110V. Spectra of radioactive sources have been recorded with the active pixel matrices using 55Fe and 3.2GeV electrons. The results are in agreement with the simulated gain and noise of the readout chain. Samples have been shipped for neutron and x-ray irradiations. Results of the characterization will be shown with particular emphasis on timing performance and radiation tolerance.

Speaker: Toko Hirono (University of Bonn)

16:50 Charge collection and ionizing radiation tolerance of CMOS Pixel Sensors using the 0.18 μm CMOS process

The Circular Electron Positron Collider (CEPC) as a Higgs Factory was proposed by the Chinese high energy physics community in 2012. To fulfill the stringent requirements, the vertex detector must be constructed based on sensor technologies that push for fine pitch, low power consumption and fast readout. Among the candidate technologies, CMOS Pixel Sensors (CPS) has demonstrated excellent performance as vertex detectors. However, it remains challenging to lower the power consumption down to 50 mW/cm$^2$ or below for its application to the CEPC vertex detector. This work presents the preliminary studies on the sensor optimization to reduce the analog power consumption, which is mostly determined by the collected charge over input capacitance ratio (Q/C). Detailed studies are performed on the charge collection as well as the ionizing radiation tolerance of CMOS pixels sensors using a 0.18 μm CMOS imaging process. This process allows high-resistivity (~kΩ∙cm) epitaxial layers, leading to significant improvements on charge collection. In addition, the sensitive volume is partially depleted, which accelerates the charge collection and hence improves substantially its tolerance on non-ionizing radiation damage. To exploit these features, we have performed detailed 3-D simulations with the Sentaurus-TCAD package. The boundaries treated with the reflective boundary condition, as a standard method used in Sentaurus-TCAD, usually lead to overestimated signals. Defining artificially high recombination velocity at the interface can partially alleviate the problem but has been found unreliable due to the arbitrary recombination rate. We propose a new approach by extending the auxiliary silicon surrounding the simulated pixel cluster to hundreds of micro-meters, which approximates the real device condition. Together with the simulation studies, we have designed the first exploratory prototype for sensor optimization. It hosts matrices with 32 different pixels types, which vary in terms of pixel pitch, as well as size and geometry of the collection electrode. We expect to compare the simulation results with the measurements of the prototype.

Speaker: Dr Ying Zhang (IHEP)

HSTD10_YZHANG-20150926.pdf

18:00 → 19:00 Dinner (eat together)

19:00 → 21:00 After dinner POSTER session, with drinks: (All presenters are requested/encouraged to attend their posters; All participants are requested to participate the session, with drinks!): POSTER size: 80cm (wide)×120cm (high)

Conveners: Marcela Mikestikova (Acad. of Sciences of the Czech Rep. (CZ)), Stephen Mcmahon (STFC - Rutherford Appleton Lab. (GB))

19:00 POSTERS: Simulations and Manufacturing:

19:01 3D simulation and modeling of ultra-fast 3D silicon detectors

3D simulation and modeling of 3D silicon detectors with short electrode spacing and relatively thin thickness (200μm) have been showed in this paper. The column spacing L_p is in the range of 5μm to 10μm. At a bias voltage of only a few volts, this structure’s response time can be as fast as 10’s of ps. In this paper, we will report some simulated electrical characteristics of this detector structure through systematic 3D simulations by Silvacos TCAD tools. Detector electric potential, electric field, hole concentration, leakage current, and capacitance at various bias voltages will be presented. The full depletion voltages calculated by CV characteristics are compared by those obtained from potential and holes concentration profile simulations.

Speaker: Ms Manwen Liu (Xiangtan University)

19:02 Modeling and simulation of spiral Si Drift Detecter

A spiral Si Drift Detector structure is simulated using a 3D TCAD tool. Electrical characteristics including electrostatic potential, electric field, leakage current, and capacitance have been simulated in detail. It has been found in simulations that both leakage current and the voltage to reach the geometry capacitance (full depletion voltage, Vfd) increase with radiation fluence. In addition, the simulation of Single Event Effects (SEE) are also important. High energy proton, neutron, alpha particle can cause Single Event Effects in semiconductor device used in aircraft electronic system, which affects the reliability and lifetime of an aircraft. The 3D device numerical simulation of Single Event Effect is performed using DESSIS.

Speaker: Ren Xiao (Xiangtan University)

19:03 The new low-capacitance silicon pixel detector performance simulation

In order to obtain the high sensitivity Silicon Pixel Tracker(SPT), we gain the low capacitance which can reduce noise and improve signal-noise ratio through modeling and simulating the different type of the junction electrode structure by Sivalco TCAD. Then we get the electrical performance of capacitance, leakage current, electron concentration and electric field distribution. Through the simulation, we can predict and design new low capacitance SPT.

Speaker: Xiong Bo (Xiangtan University)

19:04 3D simulation of electrical characteristics for detector of combining silicon biasing adaptor with silicon drift detector

Silicon drift detector (SDD), which is the detector of low capacitance because of the small area’s anode, has many novel characteristics and advantages within the small electronics noise, high energy resolution, fast response time, and good position resolution. Due to these properties, SDD has been widely used in the fields of aerospace, medical science and high energy physics experiments. By analyzing the traditional SDD properties, it has been found that the power consumption of the SDD array was enormous, and that the suitable resistors as dividers could not be found easily in one’s stockroom. To solve these problems, we came up with combining the silicon biasing adaptor (SBA) with the silicon drift detector (SDD).The combining detector structure is simulated using a 3D Silvaco TCAD tool. It has been found in simulations that both leakage current and the voltage to reach the geometry capacitance (full depletion voltage, Vfd) increase with radiation fluence. Compared with the conventional SDD, the SBA-SDD has the better electrical characteristics.

Speaker: Yuyun Li (Xiangtan University)

19:05 A Novel CMOS Electrode Readout Scheme for High Purity Germanium Detectors

In this work a novel CMOS electrode readout scheme for HPGe(High Purity Germanium) detectors with a low noise and a low input capacitance has been presented. It is a new architecture which is different from the existing planar or coaxial or PC-HPGe (Point-Contact High Purity Germanium) detectors. We propose a readout scheme with double layers of grid electrodes on both top and bottom of the Germanium crystal. Each readout channel has a similar readout structure to the parallel planar electrode readout, but taking the advantage of pixel sensors instead of the plants. The CMOS pixel readout electrode is named Topmetal-II-. From our measurement the ENC (Equivalent Noise Charge) value is 13 e- and the input node capacitance is around 20fF. Some basic characteristics of this scheme such as the capacitances, electric field, parameters of the sensitive region and so on are also simulated and presented. Due to such a low noise and a low integrate capacitance, this scheme would be a competitive candidate for the dark matter detection.

Speaker: Ms Yan Fan (Central China Normal University)

A Low Noise CMOS Electrode Readout Scheme For High Purity Germanium Detectors.ppt

19:06 POSTERS: Pixels (including CCD's) - X-ray imaging:

19:07 Development of X-ray Imaging system with SOI Pixel Detectors

The authors are developing the X-ray imaging system by using a Silicon-On-Insulator (SOI) technology. This system consists of the integration type SOI pixel detectors, named INTPIX4, and the DAQ system based on the multi purpose readout board, named SEABAS2 (Soi EvAluation BoArd with Sitcp 2). As in the past, the parallel readout have been already implemented to INTPIX4 and it realized speedup. However, the total throughput of the DAQ system became the new bottleneck. In order to solve this problem, the parallel processing (data taking process and data storing process) and FIFO buffer were implemented for DAQ software. In result, DAQ throughput was increased to 90Hz (613Mbps) from 6Hz (41Mbps). The authors tried to apply this new DAQ for the X-ray imaging at KEK photon factory. First X-ray imaging was tested at PF BL-14C (33.3keV mono X-ray), integrated still X-ray images of small samples (dried anchovy, red pepper, electrical parts) were taken. Second time was tested at PF BL-14B (9.5keV mono X-ray), integrated still X-ray images for 3D (3-dimensional) CT (Computerized Tomography) of dried anchovy were taken. Sample was taken every 1 degree rotating, total 181 times. These images were reconstructed as the high resolution 3D CT data. The detail of these X-ray tests will be shown in presentation.

Speaker: Ryutaro Nishimura (The Graduate University for Advanced Studies (KEK))

Poster Development of X-ray Imaging system with SOI Pixel Detectors.pdf

19:08 Soft X-ray performance of Back-illumination type of the Kyoto's X-ray Astronomical SOIPIXs

We have been developing SOI pixel sensor (SOIPIX), "XRPIX", for future X-ray astronomical satellites, which is monolithic active pixel sensor based on the silicon-on-insulator (SOI) pixel technology. XRPIX is equipped with event-driven readout mode which offers a fast readout with the timing resolution better than 10 micro sec by reading out the hit pixels only. We started development of the back-illuminated type of XRPIX with the dead layer less than 1 um in order to observe soft X-rays with the energy lower than 1 keV. As a first step of the development, we processed two types of back-illuminated XRPIXs (BI-XRPIX), one of which is produced with "Pizza process" developed by LBNL and the other is processed with the ion implantation and laser annealing. We irradiated the BI-XRPIXs with soft X-ray and investigated soft X-ray performances. The ratio between the counting rates of Ti-K (4.5 keV) and Cu-K (8.0 keV) X-rays suggests that the current version of BI-XRPIX with the Pizza process has the dead layer thickness of 2.0 (+1.1, -0.6) um. The measurements of the charge collection efficiency and spectral quality are under way. We will report the latest results from soft X-ray evaluation in the presentation.

Speaker: Dr Makoto Itou (Kyoto University)

19:09 Reducing the cross-talk between the sensor and circuit layers in the Kyoto's X-ray Astronomical SOIPIXs

We have been developing X-ray SOIPIXs, "XRPIX", for future X-ray astronomy satellites based on the silicon-on-insulator (SOI) CMOS technology. XRPIX is equipped with a function of "event-driven readout", which allows us to read out the hit pixels only in order to realize a high time resolution better than 10micro sec. Current version of XRPIX suffers from significant degradation of the readout noise in the event-driven readout mode compared with that in the frame readout mode, in which all the pixels are read out serially. Previous studies have clarified that it is due to cross-talks between buried P-well (BPW) in the sensor layer and in-pixel circuits in the circuit layer. Thus, we newly developed Double SOI (DSOI) type of XRPIX and reduce the cross-talks. The DSOI wafer has an additional silicon layer working as an electrical shield between the BPW and the in-pixel circuits. We confirmed successful reduction of the cross-talk by observing the analog waveform of the pixel circuit. We will give results on the X-ray performance in the presentation.

Speaker: Dr Shunichi Ohmura (Kyoto Univ.)

19:10 POSTERS: Pixels (including CCD's) - Charged particle tracking:

19:11 Development of planar pixel modules for HL-LHC

To meet the challenges of tracking at the luminosities delivered by the HL-LHC requires upgrades of tracking systems. To perform pattern recognition and vertexing in events with pile-up of up to 200 requires a larger area pixel system within the tracker. This paper reports on the development of large area planar detectors for the outer pixel layers and pixel endcaps. Large area sensors of area 2x2cm2 have been fabricated and mounted onto 4 FE-I4 readout ASICs, so called quad-modules, and their performance evaluated in the laboratory and testbeam to evaluate noise, threshold and bump-bond yield. The current-voltage characteristics of the sensors have been studied and this has been used to improve the design of the biasing, guard rings. Studies of sensors matched to a single Fe-I4 with AC and DC coupling to the front-end electronics have been made, and their noise and tracking performance compared. Sensors with different geometries have been fabricated and characterised in the laboratory and their tracking performance evaluated. A particular challenge in producing thinned large area modules is the bump-bonding, where low yield can be observed due to bowing of the sensor and readout chip during the bonding process. A new bump-bonding process using backside compensation to address the issue of low yield will be described and results of bump yield presented.

Speaker: Anna Macchiolo (Max-Planck-Institut fuer Physik (Werner-Heisenberg-Institut) (D)

19:12 CMS Pixel Upgrade for the Phase I: Module Production and Qualification

The present CMS pixel detector has been designed to be fully efficient up to luminosity of 1e34 cm-2 s-1. The instantaneous luminosity of LHC will be raising up to 2e34 cm-2 s-1 in coming years. Therefore a new detector will be built and installed in the extended year-end technical stop (YETS) in 2016-17. It will consist of four barrel layers and three disks in each endcap (one layer more with respect to the current pixel detector, barrel and disks). Modules for the barrel pixel detector are in production since Spring/Summer 2015 in five different centers. Module production requires first testing components independently and then bump bonding, wire bonding and gluing processes to finally assemble a full module. To have a uniform performance of all modules the standard qualification procedures have been developed. All modules will pass thorough 10 thermal cycles between +17C and -25C and then electrical tests in the temperature and humidity controlled environment at +17C and -20C. In addition, performance of the modules will be verified under high rate X-rays. Internal calibrate signals used for electrical tests will be calibrated in units of electrons using well defined X-ray fluorescence lines from different target materials. The qualification criteria based on which modules are selected to be used in the final system will be explained in details. Finally, the status and challenges of the production are reported.

Speaker: Mercedes Minano Moya (National Taiwan University (TW))

19:13 CMS FPix sensor study for phase I upgrade

The next incarnation of the CMS forward pixel detector, to be installed at the year end extended technical stop 2016-17, will need to survive an integrated luminosity of 300 fb^-1 with the inner radius of the active region of the disks decreasing from 6 to 4.5 cm. Based on the Run 1 experience and irradiation studies, the Phase 1 FPIX sensors will again be n-on-n DOFZ, with parameters similar to those in the present run. We will review the design choices including a study during the prototyping phase to explore different p-stop layouts. Results from the quality assurance probing of the first batches of sensor wafers will be described. The IV measurements are particularly impressive with current densities in range of 3-4nA/cm^2 at the full depletion voltage.

Speaker: Dr Kai Yi (University of Iowa)

CMSFPixSensorPhaseIbest.pdf

19:14 Test-beam evaluation of newly developed n+-in-p planar pixel sensors aiming for use in high radiation environment

Radiation-tolerant n+-in-p planar pixel sensors have been under development in cooperation with Hamamtsu Photonics K.K. (HPK). This is geared towards applications in high-radiation environment, such as for the Inner Trackers (ITk) placed inside the ATLAS detector in the high luminosity LHC (HL-LHC) experiment. Prototypes of those sensors have been produced, irradiated and evaluated through past years. In the previous studies, it was reported that significant drops in the detection efficiency were observed after irradiation, especially under bias structures. The bias structures are made up of poly-Si or Al bias rails and poly-Si bias resistors. The structure is implemented on the sensors to allow quality checks to be performed before the bump-bonding process. To minimize the efficiency drop, several new pixel structures have been designed with bias rails and bias resistors relocated. Several test-beams have been carried out to evaluate the drops in the detection efficiency of the new sensor structures after irradiation. Newly developed sensor modules were irradiated with proton-beams at Cyclotron and Radio-Isotope Center (CYRIC) in Tohoku University to see the effect of sensor-bulk damage and surface charge-up. An irradiation with gamma-rays was also carried out at Takasaki Advanced Radiation Research Center, aiming for decoupling the effect of surface charge-up from that of bulk damage. Those irradiated sensors have been evaluated with particle beams at DESY and CERN. Comparison between different sensor structures confirmed significant improvements in minimizing efficiency loss under the bias structures after irradiation. The results from gamma-irradiation also enabled cross-checking the results of a semiconductor technology simulation program (TCAD). Co-authors: ATLAS-Japan silicon collaboration, ATLAS PPS collaboration

Speaker: Kimihiko Kimura (Tokyo Institute of Technology (JP))

Hiroshima-poster_Kimura.pdf

Hiroshima-poster_Kimura.pptx

19:15 A Novel Source-Drain Follower for Monolithic Active Pixel Sensors

Monolithic active pixel sensors or MAPs receive interest in tracking applications in high energy physics as they integrate sensor and readout electronics in one silicon die with potential for lower material budget and cost, and better performance [\[1\]][1]. Source followers (SFs) are widely used for MAPs readout: they increase charge conversion gain (1/C$_{eff}$) because the follower action compensates part of the input capacitance. Charge conversion gain is critical for analog power consumption and therefore for material budget in tracking applications, and also has direct system impact [\[2\]][2]. This paper presents a novel source-drain follower (SDF), where both source and drain follow the gate potential further improving charge conversion gain. For the Inner Tracking System (ITS) upgrade [\[3\]][3] of ALICE experiment at CERN, low material budget is a primary requirement. The circuit was studied as part of the effort to optimize the effective capacitance of the sensing node. Collection electrode, input transistor and routing metal all contribute: reverse sensor bias reduces the collection electrode capacitance. The novel SDF circuit eliminates the contribution of input transistor, reduces the routing contribution if additional shielding is introduced, and has a voltage gain closer to unity than the standard SF. The SDF circuit is somewhat larger with somewhat lower bandwidth, but this is acceptable in most cases. A test chip, manufactured in a 180 nm CMOS image sensor process, implements small prototype pixel matrices in different flavors to compare readout with standard SF, novel SDF, and novel SDF with additional shielding. The effective sensing node capacitance was measured using a $^{55}$Fe source. Increasing reverse substrate bias from 1 to 6 V reduces the overall sensing node capacitance for the standard SF by 38%. The SDF provides a further 9% improvement. The SDF circuit with additional shielding provides 18% improvement, and combined with 6V reverse bias yields almost a factor 2. [1]: http://dx.doi.org/10.1016/j.nima.2014.07.017 [2]: http://dx.doi.org/10.1016/j.nima.2014.05.027 [3]: http://dx.doi.org/10.1088/0954-3899/41/8/087002

Speaker: Chaosong Gao (Central China Normal University CCNU (CN))

A Novel Source-Drain Follower for the Monolithic Active Pixel Sensors poster.pdf

19:16 Study of built-in amplifier performance on HV-CMOS sensor for the ATLAS Phase-II Strip Tracker Upgrade

The presentation will focus on the performance of analog readout electronics (built-in amplifier) integrated on the high-voltage (HV) CMOS silicon sensor chip, as well as its radiation hardness. Since a CMOS sensor has a ten times lower total collected charge from MIP than for conventional planar sensor, it is crucial to integrate a low noise built-in amplifier on the sensor chip to improve the signal to noise ratio of the system. As part of the investigation for the ATLAS strip detector upgrade, a test chip that comprises several pixel matrices with different geometry, as well as standalone amplifier and built-in amplifier in pixel arrays has been fabricated in a 0.35 .m high-voltage CMOS process. Measurements of the gain and the noise of both the standalone amplifiers and built-in amplifiers in pixel arrays respectively were performed before and after gamma radiation up to 100Mrad. A special interest is the variation of the noise as a function of the sensor capacitance. We optimized the configuration of the amplifier for a fast rise time to adapt to the LHC bunch crossing period of 25 ns, and measured the timing characteristics including jitter. Our results indicate an adequate amplifier performance for monolithic structures used in HV-CMOS technology. The results are incorporated in the next submission of a large-structure chip.

Speaker: Zhijun Liang (University of California,Santa Cruz (US))

A0poster_hiroshimaxian_zhijun_v3.pdf

19:17 POSTERS: Strips:

19:18 Bonding Study towards Quality Assurance of the Belle-II Silicon Vertex Detector Modules

The silicon vertex detector (SVD) for the Belle-II experiment comprises four layers of double-sided silicon strip detectors (DSSDs), assembled in a ladder-like structure. Each ladder module of the outermost SVD layer has four rectangular and one trapezoidal DSSDs supported by two carbon-fiber ribs. In order to achieve a good signal-to-noise ratio and minimize material budget, a novel chip-on-sensor "Origami" method has been employed for the three rectangular sensors sandwiched between the backward rectangular and forward (slanted) trapezoidal sensors. The poster describes the bonding procedures developed for making electrical connections between sensors and signal fan-out flex circuits (aka, pitch adapters), and pitch adapters and readout chips as well as the results in terms of the achieved bonding throughput and pull force.

Speaker: Mr Kookhyun Kang (on behalf of the Belle-II SVD Collaboration)

19:19 Embedded pitch adapters: a high-yield interconnection solution for strip sensors

The interconnection of sensors and readout electronics is a subject of critical importance in the module design for High Energy Physics experiments, such as ATLAS. The sensors are made progressively larger, and the readout electronics smaller, and both contain increasingly more channels. The actual realization of the electrical connection between channels is not trivial and it becomes a yield issue when the experiment contains tens or hundreds of millions of strip channels. The question is not anymore if the bonding can be done, but if it can be done reliably enough to build a whole tracker in the required production time. A proposal to fabricate large area strip sensors with integrated, or embedded, pitch adapters is presented for the End-Cap part of the Inner Tracker in the ATLAS experiment. To implement the embedded pitch adapters, a second metal layer is used in the sensor fabrication, for signal routing to the ASICs. Sensors with different types of embedded pitch adapters have been already fabricated in order to optimize the design and technology. Considerations on signal noise, pick-up, cross-talk, efficiency loss, and also on sensor yield reduction and technological limitations have been taken into account in the design and technology development, and will be discussed. Interstrip capacitance tests taking into account all channel neighbors will be shown which reveal the important differences between the various designs considered. Noise figures obtained in full assembled modules will be correlated with these interstrip capacitance tests, showing that the tests performed on the bare sensors are a valid tool to estimate the final noise in the full module. The full modules have been taken to beam test in order to examine the incidence of cross-talk, pick-up, and signal loss. The detailed analysis will expose the performance difference between the different designs and the influence of technological factors such as second-metal track width or inter-metal oxide thickness. Finally, first results on irradiated sensors will be shown.

Speaker: Miguel Ullan Comes (CNM-Barcelona (ES))

Poster_Embedded-PA_Hiroshima15.pdf

19:20 Noise evaluation of silicon strip super-module with ABCN250 readout chips for ATLAS detector upgrade at high luminosity LHC

Toward the High Luminosity LHC (HL-LHC) runs, the whole of ATLAS inner trackers will be replaced. The SemiConductor Tracker (SCT) using silicon micro strip sensors for tracking of the charged particles willalso be fully replaced. Dedicated readout chips, ABCN250, for the new SCT sensor are being developed for the HL-LHC. The $10 \times 10$ cm${}^2$ strip sensors and the readout chips are integrated into a module. The ABCN250 chips are mounted on hybrid. The strips on the sensor and the readout channels of the chips are wire-bonded directly. A block of these modules are integrated to be a larger structural and electrical unit. The super-module is one of such concept of integration where double-side of the module form an unit, then, a block of double-side modules are mounted on a support frame. We have assembled eight double-side modules equipped with more than 600 ABCN250 chips as a super-module prototype which has more than 80,000 channels of sensors. When multiple sensors and readout chips are operated on a large structure simultaneously, crosstalk between the channels could increase the noise. It is necessary to measure the noise on super-module prototype. In order to readout and test the sensors with the ABCN250 chips on super-module prototype, we have developed a new data-acquisition system utilizing a readout board called SEABAS. The SEABAS has FPGAs: one incorporates TCP/IP communication with PC in a firmware layer, the SiTCP technology, to communicate with PC, and the other, user-FPGA, to communicate with the user-specific hardware with user-specific firmware. To detect unknown issue on bit stream from readout chips, firmware on user-FPGA for our system passes raw bit stream without processing. With the new data-acquisition system, entire system of the super-module prototype was successfully readout and all the channels were tested simultaneously. The distributions of the input noise and the accidental hit rate were evaluated.

Speaker: Kazuki Todome (Tokyo Institute of Technology (JP))

19:21 POSTERS: New materials, New technologies:

19:22 Performance evaluation of newly developed SrI2(Eu) scintillator

The development of europium-doped strontium iodine (SrI2(Eu)) has attracted considerable attention, because of its excellent material priorities as regards gamma-ray scintillator applications. These include its excellent energy resolution, high light output (~80,000 ph/MeV), and high effective atomic number (Z = 49). Here we report on the performance of Φ1” × 1” SrI2(Eu) cylindrical crystals newly fabricated by Union Materials Inc. In this study, we measured the energy resolution, light output, and scintillation decay time at 10 degree temperature intervals between -40 and 40℃, using an optically coupled 2-inch photomultiplier tube (PMT) (Super Bialkali, Hamamatsu). The SrI2(Eu) light output increased by 0.68 %/℃ as the temperature decreased. At -20℃, we obtained the optimum energy resolution recording 2.94 ± 0.02% full width at half maximum (FWHM) for 662-keV gamma rays measured with Cs-137. For comparison, we also measured the same crystal using both a large-area (19 × 19 mm2) avalanche photodiode detector (APD) and 8 × 8 multi-pixel photon counter (MPPC) arrays of 3 × 3 mm2 pixels. Optimum energy resolutions of 3.14 ± 0.06% and 3.99 ± 0.01% were obtained with the APD and MPPC, respectively, as measured at -20℃ with a shaping time of 10 (PMT and APD) or 5 μs (MPPC). We also measured the internal background of SrI2(Eu) in a cave composed of Cu-Pb blocks with their thickness of 5—10cm confirming that SrI2(Eu) has an extremely low internal background. In this study, we have shown that SrI2(Eu) is a promising scintillator that can be utilized for radiation measurements incorporating low-energy X-rays to high-energy gamma rays, and can thus be applied in various medical, industrial, and environmental treatment fields in the near future.

Speaker: Miho Takabe (Waseda Univ)

19:23 Beam Test Results of the Dependence of Signal Size on Incident Particle Rate in Diamond Pixel and Pad Detectors

We will present beam test results of the dependence of signal size on incident particle rate in charged particle detectors based on single-crystal and poly-crystalline CVD diamond. The detectors were tested over a range of particle fluxes from 2 kHz/cm^2 to 2 MHz/cm^2. The pulse height of the sensors was measured with pad and pixel readout electronics. We will present data from the 2014 and 2015 beam tests at PSI indicating the pulse height of non-irradiated single-crystal CVD diamond sensors is stable with respect to flux, while the pulse height of irradiated single-crystal CVD diamond sensors decreases with increasing particle flux. The observed sensitivity to flux is similar in both the diamond pad sensors constructed using diamonds from the Pixel Luminosity Telescope (PLT) irradiated during its pilot run in CMS detector and in neutron irradiated diamond pad sensors from the same manufacturer irradiated to the same fluence of neutrons. The pulse height for unirradiated and irradiated poly-crystalline CVD diamond pad sensors was observed to be stable with respect to particle flux. This work is presently being extended with rates up to 20MHz/cm^2 in both polycrystalline and single-crystal CVD diamond pad and pixel detectors. The latest test beam results for both single-crystal and poly-crystalline CVD diamond will be shown.

Speaker: Felix Caspar Bachmair (Eidgenoessische Tech. Hochschule Zuerich (CH))

19:24 Semiconductor simulation of charge collection mechanism in CVD diamond detector

Research mechanism of charge collection is a important factor for improving the performance of diamond particle detector. With semiconductor device simulation software GSRES, numerical simulations of transport properties of carriers in diamond are carried out. The important material properties, for instance, energy gap and ionization energies, which affect in simulation are set same to pure CVD diamond with no impurity. The physical processes of transport of carriers is numerically researched by the drift-diffusion model, and the SRH recombination mechanism in semiconductor material is the main cause of the loss of charge as simulation results show. Other parameters, as electric field intensity, lifetime of carrier, mobility and saturated velocity of carriers, which influences the charge collection rate is studied. The simulation results is compared to theoretically analysis, and shows well agreement. This numerical research method would be useful in CVD diamond detector development and improvement.

Speaker: Li Yong (Northwest Institute of Nuclear Technology，Xi’an 710024, China)

19:25 POSTERS: Electronics:

19:26 The VeloPix ASIC for the LHCb VELO Upgrade

The LHCb Vertex Detector (VELO) will be upgraded in 2018 along with the other subsystems of LHCb in order to enable full detector readout at 40 MHz. LHCb will run without a hardware trigger and all data will be fed directly to the software triggering algorithms in the CPU farm. The upgraded VELO is a lightweight silicon hybrid pixel detector with 55 um square pixels, operating in vacuum in close proximity to the LHC beams. The readout will be provided by a dedicated front end ASIC, dubbed VeloPix, matched to the LHCb luminosity requirements. VeloPix is a binary pixel chip with a matrix of 256 x 256 pixels, covering an area of 2 cm^2. It is designed in a 130 nm CMOS technology, and is closely related to the Timepix3, from the Medipix family of ASICs. The principal challenge that the chip has to meet is a hit rate of up to 900 Mhits/s/ASIC, resulting in a data rate of more than 16 Gbit/s. Combining pixels into groups of 2x4 super-pixels enables the use of shared logic and a reduction of bandwidth due to combined address and timestamp information. The pixel hits are combined with other simultaneous hits in the same super-pixel, timestamped, and immediately driven off-chip via custom designed 5.12 Gbit/s serialisers. The power consumption of the analog front end is about 5 uW per pixel, and the total power consumption of the ASIC is less than 2 W. An extensive testbeam and lab test campaign is underway in order to characterise prototype upgrade VELO sensors and simultaneously study the performance of the Timepix3 chip in a high track rate environment. These measurements provide valuable input to the VeloPix project. The VeloPix ASIC design is nearing completion and the chip is expected to be submitted in the autumn. The current status of the ASIC design, performance simulations and prototyping will be described, along with recent lab and testbeam results.

Speaker: Xabier Cid Vidal (CERN)

XabierCid_HSTD10_Poster.pdf

19:27 Results on 3D interconnection from AIDA WP3

From 2010-2014 the EU funded AIDA-WP3 project invest established a network of groups working collaboratively on advanced 3D integration of electronic circuits and semiconductor sensors for applications in Particle Physics. The main motivation came from the severe requirements on pixel detectors for tracking and vertexing at future Particle Physics experiments at LHC, Super-B factories and Linear Colliders. To go beyond the state-of-the-art, the main issues are studying low mass, high bandwidth applications, with radiation hardness capabilities, with low power consumption, offering complex functionality, with small pixel size and without dead regions. The interfaces and interconnects of sensors to electronic readout integrated circuits are a key challenge for new detector applications. WP3 was structured in eight subprojects sampling different 3D technologies using different vendors. Some subprojects investigated 3D technologies which have the potential to lead to high-density 3D interconnection processes but still have significant technological challenges. This included high density, high aspect ratio vias in via first and via last technologies. The SLID (Solid Liquid Interdiffusion) technology was used for high density interconnection of sensors and electronics or two electronic tiers. Others used more mature technologies with large diameter vias and standard bump bonding offering more modest possibilities for improvements of the detector performance but still considerable advantages compared to standard detector technologies. This paper presents the final results of the AIDA WP3 project, summarize and compare similar results from other projects, and indicate future research activities in this field.

Speaker: Hans-Guenther Moser (MPI fuer Physik)

Poster Hiroshima.pdf

Poster Hiroshima.pptx

19:28 Development of a low-noise, area efficiency, 4-order readout circuit for silicon pixel detectors

In recent years, silicon detectors are widely used in X ray imaging for medical and astronomical applications. The signal induced by some particles is so weak that specified readout circuit is required. The readout circuit can be connected with silicon detectors by AC-coupling or DC-coupling method. DC-coupling is prefered for pixel detectors, since the AC-coupling capacitors required occupy much space and increase the complexity of the system, especially for large pixel array. However, the leakage current from the silicon crystal can be integrated on the feedback capacitor in charge sensitive amplifier (CSA). After a period, the operation point of the amplifier can be changed and it can not work well. Thus, the leakage current must be considered in the readout circuit design. Moreover, the area of one channel is limited by the system specification. This work will present an ASIC readout circuit development, which aims to achieving low noise and area efficiency. In order to compensate the leakage current, a dual CSA has been designed based on the previous works. The gain is increased. Pole-zero cancellation is also implemented to eliminate the overshoot/undershoot appearing in the output of shaper. A 4-order shaper is designed to obtain a Semi-Gaussian wave and further decrease the noise deduced by the leakage current. This circuit has been design and fabricated in a standard commercial 2P4M 0.35 $\mu m$ CMOS process. Die area of one channel is $1190 \mu m \times 147 \mu m$. The input charge range is 3 fC. The peaking time can be adapted from 1 us to 3 us. Measured ENC is about $70 e^-$ at input capacitor of 0 F. The gain is 180 mV/fC at the peaking time of 1 $\mu s$. The circuit is still under test. More measured results will be presented in this symposium.

Speaker: Dr JIA WANG (Northwestern Polytechnical University)

19:29 Design of Low Noise and Low Area Preamplifier-Shaper in Readout ASICs for CdZnTe Semiconductor X-ray and γ-ray Detectors

CdZnTe detectors are good candidates for high-efficiency, high-resolution, and room-temperature nuclear radiation detectors, and are especially suitable for the detection of the X-ray and γ-ray in the energy range of 20-800 keV. They are being widely used in environmental monitoring, medicine, industrial non-destructive testing, security inspection and space science. We report the study on the design of low noise and low area preamplifier-shaper in readout ASICs for CdZnTe detectors. We focus on the preamplifier-shaper configurations with proper shaping times and filtering frequencies for obtaining low noise, and several realizations of the feedback resistor (including poly resistor, single MOS resistor, serial MOS resistors and a resistor circuitry) in the shaper are studied for achieving low area. These circuits were realized in three experimental chips and were fabricated in 0.35 µm processes. The design with poly resistor achieves the lowest noise and the best linearity, but takes the largest area. The design with single MOS resistor achieves the lowest area, but the gain of the shaper is limited for keeping a good linearity. The designs with serial MOS resistors and with the resistor circuitry also work well with gain limitations of the shapers. In order to get a proper gain for the whole circuits, an additional amplifying stage followed the shaper has been included in each design. The gain linearity of the whole circuits and the equivalent noise charge (ENC) were tested. The test results indicate that the gain linearity is above 99.9% and ENC is around 200e@5pF for each design. With a radiation source of 241Am and a CdZnTe detector of 3 × 7 × 3 mm3, the tests of energy spectrums are being conducted. The expected energy resolution is below 5% for 59.5 keV.

Speaker: Dr Jia WANG (Northwestern Polytechnical University)

19:30 A 4 x 8 Gbps VCSEL Array Driver ASIC and Integration with A Custom Array Transmitter Module for the LHC Front-end Transmission

VCSEL-based parallel optical data links have recently seen rapid and wide-spread deployment in high performance computing labs, data centers and Ethernet networks. The benefits include highly aggregated bandwidth, compact footprint and low power consumption. To apply the parallel optics in high energy physics, for example, in the LHC upgrades as well as other collider detector developments, the devices also have to meet rigid environmental demands of radiation, electro-magnetic field and temperature. Two critical developments, the array driver ASIC and the precision optical interface assembly, are indispensable towards a dedicated array optical transmitter for on-detector deployment. In this paper, we present the design and test results of the LOCld2014 ASIC, a 4 x 8-Gbps VCSEL array driver fabricated in a commercial 0.25- µm Silicon-on-Sapphire(SOS) CMOS technology. This is the first VSCEL array driver ever fabricated at this aggregated bandwidth targeting the high-energy physics experiments. The LOCld2014 receives a low-swing CML signal (differential p-p 200 mV), outputs a 7.5 mA modulation current with a 6.25 mA bias current. Programmable active-shunt-peaking technique is used to extend the bandwidth in pre-driving stages. A novel structure of the output stage removes the ordinary extra bias-circuit, and delivers both bias and modulation current with balanced branches to effectively minimize the switching signals on the power supply and crosstalk. After integrated within a custom array optical transmitter (ATx), the LOCld2014 is able to be fully tested. The ATx module, while utilizing generic mechanical optical interface (MOI) and optical turn fiber ribbon, is assembled via a custom active alignment procedure. The optical eye diagram of each channel at 8Gbps has been measured, and passed the eye mask test with adjacent channels working simultaneously. The BER < 1E-12 is achieved at each channel working at 8 Gbps with adjacent channels working simultaneously. The full data link performance and crosstalk evaluation of the LOCld2014 will be presented in the paper. The X-ray irradiation tests of the whole module including the LOCld2014 will be conducted, and the results will be reported.

Speaker: Dr Di Guo (Southern Methodist University)

HSTD2015 Poster LOCld2014_final.pdf

HSTD2015 Poster LOCld2014_final.ppt

19:31 Development of Low-noise High-speed Analog ASIC for X-ray CCD Cameras and Wide-band X-ray Imaging Sensors

We report on the performance evaluation of the readout ASIC developed for onboard X-ray CCD cameras in astrophysics. The quick and low-noise readout is essential for the pile-up free imaging spectroscopy with the future highly sensitive telescope. Our goal is the readout noise of 5e- rms at the pixel rate of 1Mpix/sec, which is about 10 times faster than those of the currently working detectors. We had successfully developed a low-noise mixed-signal Application Specific Integrated Circuit (ASIC) as the front-end electronics of Soft X-ray Imager (Nakajima et al. 2013, NIMA, 731, 166; Nakajima et al. 2014, JAXA-RR-14-007) onboard the ASTRO-H satellite that will be launched in this Japanese fiscal year. However, the noise performance was limited at the pixel rate higher than 250 kpix/sec. Then we have designed and developed the new ASIC with the fourth-order Delta Sigma modulators to enhance its inherent noise-shaping performance. It was fabricated through Taiwan Semiconductor Manufacturing Company (TSMC) 0.35 um CMOS process. It consists of four identical circuits that process the CCD signal simultaneously. The input signal range of ±20 mV covers the effective energy range of the typical X-ray photon counting CCD (up to 30 keV). Our Delta Sigma circuit can also be applied to the other X-ray wide-band imaging sensors such as SOIPIX (Arai et al. 2011, NIMA, 58, 2528). We present the obtained performances of the new ASIC such as the input equivalent noise, integrated non-linearity, as well as the radiation tolerance against the single event latch-up and total ionizing dose. We also briefly report the results obtained from the integrated test with a fully-depleted P-channel X-ray CCD.

Speaker: Dr Hiroshi Nakajima (Osaka University)

19:32 A low-latency and low overhead encoder ASIC for the serial data transmission in ATLAS LAr calorimeter

The ATLAS LAr calorimeter readout phase-I trigger upgrade calls for a data rate of 204.8 Gbps for each front-end board (LTDB). These data will be transmitted over optical fibers to the back-end. The optical link transmitter side consists of an encoder, a serializer and a custom optical transmitter. The encoder receives data from the upstream ADCs and encoded the data into frames. The LOCic ASIC has been developed with a 0.25 micron Silicon-on-Sapphire CMOS technology. The front-end ADCs are 12-bit 40 MSPS ADCs with 640 Mbps serial output. The custom data frame comprises of 112-bit scrambled ADC data, 8-bit CRC (Cyclic Redundancy Check) code and 8-bit frame header. The 8-bit frame header, used to identify the frame boundary, also provides the capability to quickly re-synchronize the frame boundary if the serial data shift a few bits due to radiation. The LOCic comprises of a synchronous FIFO, a CRC generator, a scrambler, a header generator and a frame builder to composite the data. To reach the clock frequency of 640 MHz we adopted pipeline technique to simplify the circuit logic executed in each clock period, especially in the CRC generator with a limit of 8 XOR logic units in each step. LOCic has been tested using a Kintex 7 FPGA evaluation board. The FPGA implemented a ADC emulator and a decoder. The decoder identifies the data frame boundary correctly and the recovered ADC data pass the CRC code check. The latency of the encoder is about 7 ns and the over

Speaker: Le Xiao (CCNU)

Final Poster LOCic.pdf

19:33 POSTERS: Radiation damage, Environmental monitoring:

19:34 Compensation for radiation damage of SOI pixel detector via tunneling

We are developing a method for removing trapped holes in the oxide layer of SOI monolithic pixel detector after irradiation. Radiations that pass through detector generate electron-hole pairs in the oxide layer. The holes are captured in the oxide layer due to lower mobility than the electron’s. Positive potential of these trapped holes modify characteristic of MOSFETs of signal readout circuit. In order to compensate the effect of positive potential, we tried to annihilate the trapped holes by using the electrons via Fowler-Noldheim tunneling. Applying high voltage to the oxide layer with MOSFET and buried p-well (BPW) under the oxide layer as electrode for 0 V and high voltage respectively, the electrons are injected into the oxide layer through junction of Si-SiO2 by FN tunneling. The sample which has different body type, gate length and width of MOSFETs was used. Before and after irradiation, Id-Vgs was measured to evaluate characteristic of MOSFETs such as threshold voltage, Vth. Current during applying high voltage to the BPW (Ibpw-Vbpw) also measured to make sure of FN tunneling. The sample was irradiated with X-ray up to 1 kGy, and then negative shift of Vth occurred. FN plot which derived from Ibpw-Vbpw showed linearity at Vbpw ≥ 120 V. This linearity indicates FN tunneling from Si surface of the BPW into the oxide layer. We succeeded to recover Vth close to pre-irradiation level after applying Vbpw ≥ 120 V. Other recent progress of this study will be shown in presentation.

Speaker: Dr Miho Yamada (KEK, High Energy Accelerator Research Organization)

19:35 Characteristics and Total Ionizing Dose Compensation of Double Silicon-on-Insulator Integration Type Sensor

We are developing monolithic pixel sensors based on Lapis 0.2 $\mu$m fully-depleted Silicon-on-Insulator (SOI) technology. The SOI pixel sensors have properties such as low leakage current, fast response, and single event effects immunity. For use in hard radiation environments as in HEP experiments, the total ionizing dose (TID) effect is the major issue since the rather thick (200 nm) buried oxide layer affects the readout circuit operation after irradiation. To compensate for TID damage, we have introduced a Double SOI structure which has a Middle Silicon layer (SOI2 layer) underneath the buried oxide layer in addition. The effects due to irradiation-induced holes trapped in oxide layers are to be cancelled by applying a negative voltage to the SOI2 layer. We studied the recovery of an integration-type Double SOI sensor from TID damage induced by $\mathrm{^{60}Co}$ gammas. The sensors irradiated to 100 kGy recovered the pixel functionality by applying a negative voltage to the SOI2 layer, and showed a response for IR laser as expected for non-irradiated sensors. Other characteristics such as cross-talk, signal shape and response to beta-rays were evaluated. The sensors are operated with full depletion as a feature of our SOI devices, allowing fast signal collection and uniform response across. We conclude that the Double SOI sensor is radiation hard enough to be used in HEP experiments in harsh radiation environments such as at Bell II or ILC.

Speaker: Mari Asano (University of Tsukuba (JP))

19:36 Laser Irradiation Experimental Studies on DDR3 for Xilinx Zynq-7010 SoC Microzed

The single event effects of DDR3 influenced on Xilinx Zynq-7010 SoC Microzed performance were tested with 1064nm laser irradiation. The major affecting factors responsible for SEE sensitive region distributions on DDR3 and the SEFI happening probabilities of SoC induced by laser irradiation on DDR3 were tested in detail. These experimental factors include the data communication modes between DDR3 and the circuit modules embedded in SoC, Microzed test board operating frequency, laser device power and its irradiation position on DDR3. The mechanisms of the SEE typical experimental results were primarily explored.

Speaker: Mrs Shuhuan Liu (Xi’an Jiaotong University, Xi’an, Shaanxi, 710049, China.)

19:37 proton radiation damage test studies on Si MCZ detector

The displacement damage induced by high energy proton irrdiation were measured with I_DLTs. The detector typical electronic parameters including I-V,C-V, and electric field profile influced by proton radiation damage were tested and analyzed.

Speaker: Mrs Shuhuan Liu (Xi'an Jiaotong Univ.)

19:38 Degradation Enhancement of Gate-controlled Lateral PNP Bipolar Transistors Induced by Mixed Irradation of Neutron and Gamma

Four types of gate-controlled lateral PNP bipolar transistors have been designed in a commercial bipolar process to investigate their sensitivity to radiation-induced degradation. New experimental and simulated results concerning neutron displacement effects, total ionizing dose effects and ionizing/displacement synergistic effects are presented. Neutron radiation effect experiments on the gate-controlled lateral PNP bipolar transistors have been performed at Xi’an pulsed reactor and the neutron fluence is up to 1×10^13 cm^(-2). Total dose absorbed by the transistors in gamma radiation effect experiments is up to 30 krad(Si). Identical transistors have been also exposed to the mixed irradiation of 1×10^13 cm^(-2) neutron and 30 krad(Si) gamma simultaneously to accomplish the ionizing/displacement synergistic effect experiments. The data reveal that the current and gain degradations induced by the mixed irradiation of neutron and gamma are notably more severe than the sum of neutron and gamma radiation degradations measured individually. Analysis that supported by device simulation shows that the positive charge in the oxide layer and Si/SiO2 interface traps induced by gamma irradiation can enhance the recombination processes of carriers in the bulk defects induced by the neutron irradiation, and this is the main cause of ionizing/displacement synergistic effects on the gate-controlled lateral PNP bipolar transistors.

Speaker: Ms Chenhui Wang (State Key Laboratory of Intense Pulsed Radiation Simulation and Effect (Northwest Institute of Nuclear Technology), Xi’an 710024, China)

19:39 The Effects of Gamma Irradiation on Neutron Sensitivity of Lateral PNP Bipolar Transistors: Investigations and Simulations

Lateral PNP bipolar transistors with different neutral base widths, base doping concentrations and emitter perimeters have been first irradiated with gamma rays then neutrons and compared to the same devices exposed to neutrons only. The data shows that gamma irradiation can make subsequent neutron displacement damage larger and this phenomenon may be due to the increased surface potential induced by the accumulated positive charge in the oxide layer above base region during gamma irradiation. In order to verify this analysis, further neutron radiation effect experiments have been accomplished on the gate-controlled lateral PNP bipolar transistors manufactured in the identical commercial bipolar process whose bias voltage of the gate is zero and 10V respectively. The data reveals that the increased surface potential simulated by the positive bias condition enhances the neutron degradation rate consistent with previous analysis. With semiconductor device simulation software TCAD, numerical simulations of the effects of gamma irradiation on neutron sensitivity have been carried out to find out the physical mechanisms by means of adding positive charge to the oxide layer above base region and changing the minority carrier lifetimes in the bulk of the transistors. The results indicate that the increased surface potential caused by first gamma irradiation affects the transportation process of electrons and holes near Si/SiO2 interface and in the bulk, leading to more rapid gain degradation of the transistors compared to those irradiated with neutrons only. These effects have important radiation tolerance implications.

Speaker: Ms Chenhui Wang (State Key Laboratory of Intense Pulsed Radiation Simulation and Effect (Northwest Institute of Nuclear Technology), Xi’an 710024, China)

19:40 Synergistic Effect of Mixed Neutron and Gamma Irradiation on Bipolar Operational Amplifier OP07

This paper present the synergistic effects on bipolar operational amplifier OP07. The radiation effects were investigated by neutron beam、gamma ray、mixed neutron and gamma ray environments. The trend and character of the synergistic effects were studied through comparison and analysis on different experiment results. Results show that the bipolar operational amplifier OP07 exhibited significant synergistic effects of mixed neutron and gamma irradiation. Besides, the bipolar transistor was considered as the most sensitive unit of the operational amplifiers. In this paper, a serial of experiments were done on bipolar transistors in different radiation environments. The synergistic effect was also observed on these transistors in the mixed neutron and gamma irradiation environments, which leads to the faster degradation of bipolar operational amplifiers. In the theoretical simulation, the geometric and calculation model based on the Medici software package have been constructed for analyzing bipolar components. The effect of mixed neutron and gamma irradiation has been simulated based on the mechanism understanding of the radiation effect on bipolar transistors, and the simulated results show that the trend is consistent with the experimental data. The results of the experiments and simulation indicate that the radiation effect of the bipolar devices in mixed neutron and gamma environments is not a simply combination of TID effect and displacement damage, and the TID effect could enhance the displacement damage. The synergistic effect should not be neglected in complex radiation environments.

Speaker: Mr Yan Liu (State Key Laboratory of Intense Pulsed Radiation Simulation and Effect, Northwest Institute of Nuclear Technology, P. O. Box 69-10, 710024, Xi’an, China)

19:41 Comparison of Single Event Effects on 28-nm SoC Under Different Radiation Environments

We conducted a number of experiments on Xilinx Zynq-7010 28-nm System on chip (SoC) , which was irradiated respectively with alpha particles, protons and laser, to study Single Event Effect (SEE) of SoC. In alpha experiments, 241Am α source at the energy of 5 MeV was used to irradiate the SoC chip. In proton experiments, 3 MeV, 5 MeV and 10 MeV mono-energetic proton beams were vertically irradiated on the SoC chip. In laser experiments, the external dynamic memory (DDR3) was vertically irradiated by 1064-nm laser because laser cannot be incident to the sensitive area in SoC, and DDR3, storing all testing program, is an important component of the test board. The plastic capsulation of SoC and DDR3 was removed in all the experiments. The results showed that Single Event Effect was induced in Xilinx SoC and DDR3. Single-bit event upset (SEU), Single Event Functional Interrupt (SEFI) and multi-bits upset (MBU) occured in different modules including PL, FPU, etc. The error types of all these experiments were similar, making experiments under different radiation environments as complement and verification to each other, which indicates that the test programs determine the test results under different circumstances. The SEU cross sections of different test modules in different experiments were obtained, and the variation trend of cross sections as functions of proton energy was explained. Comparing alpha and laser experiments, PL module was the most sensitive area while few errors happened in FPU in alpha experiments. But in laser experiments, things were completely the opposite. We found that errors were more easily to occur in FPU because FPU performed complex calculations and owned large amount of code; in contrast, few errors occurred in PL because PL completed most missions via hardware programmable logic, only using DDR for input and output values. Comparing alpha and proton experiments, the SEU cross section induced by 5-MeV α was greater than that induced by 5-MeV proton, since alpha particles have greater LET in this case. The comparison and explanation of SEE experiments utilizing different radiation sources were discussed.

Speaker: Yao Zhang (Xi'an Jiaotong University)

19:42 Single Event Effects Studies on 28-nm SoC Induced by Low Energy Proton Irradiation

Protons in earth’s space radiation environment pose a serious threat to astronautics electronic system, where System on Chip (SoC) is widely used. Therefore, we carried out low energy proton experiments on 28-nm SoC and emulated typical modules influenced by incoming particles in SoC to explore proton Single Event Effects (SEE). In the radiation experiments, the SoC chip was irradiated by protons of different energies. The irradiation test results showed that SEE occurred in typical modules of SoC, including register, PL, Cache, etc. The Single Event Upset (SEU) cross sections at different proton energies were obtained. In the simulation, protons of different energies were simulated as pulsed current source in consideration of multilayer wiring and energy loss before reaching the sensitive area. Typical structure of register and inverter in SoC were built. The circuit modules were simulated as SEE occurred and malfunctioned when pulsed current source existed. The changes of the circuit modules output were observed when pulsed current signals were placed at different sensitive nodes, the parameters of pulsed current were altered, or the circuit was working under different conditions. The sensitive nodes in typical modules and the possible reasons of test program malfunction were primarily studied.

Speaker: Yao Zhang (Xi'an Jiaotong University)

19:43 Modeling and Simulation of Radiation Effects on Si PIN Photodetectors Induced by Neutron Beams and γ Ionization Pulses

A method is presented for modeling and simulation of radiation effects on Si PIN photodetectors irradiated by neutron beams and γ ionization pulses. To focus on the modeling and simulation process, the device model, radiation models, and solution methods are described in detail. The mechanism of dark current increase of the PIN photodetectors induced by neutron radiation is analyzed. The device physics modeling and neutron radiation modeling is established to simulate the dark current of the PIN photodetectors by the device simulator. The dark current increase versus 1-MeV-equivalent neutron fluence in the range from 1×10^10 to 1×10^14 cm^-2 is presented. The γ ionization pulse radiation model is established to simulate the photocurrent of Si PIN photodetectors with the dose rates ranging from 1 to 10^9 Gy(Si)/s. The tendency of the simulation results is in agreement with the experimental results of correlative literatures.

Speaker: Dr zujun wang (Northwest Institute of Nuclear Technology)

19:44 Aging and Environmental Tolerance of Optical Transmitter for the ATLAS Phase-I upgrade at LHC

The MTx optical transmitter is developed for the ATLAS phase-I upgrade required for environmental durability. The data transmission of up to 8 Gbps is conducted with VCSELs in TOSA packaging and the custom developed LOCld laser driver of CMOS process suitable for the Large Hadron Collider (LHC) environment. We discuss the MTx design and specification. Aging tests in 85$^o$C/85%RH condition were conducted for the 10 Gbps VCSELs in bare-die and TOSA packages to evaluate non-hermetic tolerance. Tests with 30 MeV and 70 MeV protons were conducted for light degradation of the VCSELs and bit-error rates. The signal eye-diagrams of test samples were also investigated.

Speaker: Suen Hou (Academia Sinica (TW))

HSTD10_poster_MTx_20150925_v5.pdf

19:45 POSTERS: Applications in High Energy Physics, Space, Medical, Material sciences:

19:46 Prototypes and system test stands for the Phase 1 upgrade of the CMS pixel detector

The present CMS pixel detector will be replaced in the extended end of year shutdown between 2016 and 2017 with a new detector that will feature one additional tracking layer, faster readout electronics to cope with the increase in instantaneous luminosity, and a new CO2 cooling system that will help avoiding increases in the total material in the tracker. This presentation will focus on the ancillary electronics that supports the readout of the pixel detector, and on the lessons learned from system test facilities and from a prototype (pilot detector) that is currently installed in CMS. Both the system test facilities and the pilot detector employ preproduction components of the final detector. In addition to allowing tests of the full readout chain the test facilities allow for the development of the data acquisition and of all the calibration programs. With time these test facilities will evolve into test stands where the entire system will be read out and calibrated prior to the installation in CMS. Results from both the pilot detector and from the system test facilities will be presented.

Speaker: Satoshi Hasegawa (Fermi National Accelerator Lab. (US))

2015_09_HiroshimaPOSTER.pdf

19:47 Impact Parameters Simulation for the Turkish Accelerator Center Particle Factory Tracker System

A silicon tracker system was designed for the Turkish Accelerator Center Particle Factory (TAC PF) detector to track relatively low momentum charged particles. The designed tracking detector system consists of five individual cylindrical barrel modules and each module has two parallel single-sided silicon strip detector planes assembled into carbon layers. This structure has already been published. In this work, Monte Carlo simulation technique has been used to estimate impact parameters of the designed tracker system. The preliminary parameterization results have been discussed.

Speaker: Ilhan Tapan (Uludag University (TR))

19:48 Pre-clinical Results with the Proton CT Head Scanner

We report the results from CT scans with 200 MeV protons using the head scanner developed by the pCT collaboration in the last four years. The tracker is based on Fermi silicon strip detectors employing “slim edge” technology and is read out by a fast ASIC specifically designed for this application. The energy detector is a multi-stage scintillation counter permitting fast pulse shaping and high rate. The new data acquisition system permits to record a proton rate in excess of 1 MHz. We have been scanning a variety of phantoms at several hospitals with different proton beam time structures in pre-clinical trials to assess the basic scanner parameters like the accuracy of the relative stopping power (RSP) and the position resolution, as a function of phantom depth. Another crucial parameter is the performance of the scanner as a function of the dose delivered to the patient.

Speaker: Hartmut Sadrozinski (SCIPP, UC santa Cruz)

HSTD10-pCT_Poster-2.pdf

HSTD10-pCT_Poster-2.pptx

19:49 Study of a Detector System for High-Energy Astrophysical Objects Using a Combination of Plastic Scintillator and MPPC

We are studying a hard X-ray detector using a combination of a plastic scintillator and a multi-pixel photon counters (MPPC). Usually photomultiplier tubes (PMTs) have been adopted to read scintillators because of its high-gain and large photoelectric surface, and studies of PMT and scintillator systems are well advanced. However there exist limitations for PMTs. For example they have relatively large size, require high-voltage to operate and cannot be used in a strong magnetic field. On the other hand, MPPCs do not have such limitations but instead have high quantum efficiency and compact size. Therefore we are developing detectors with a combination of MPPC and plastic scintillator, primarily aiming to be used for the polarization measurements from high-energy astrophysical objects. With high quantum efficiency and fast response of MPPCs, we expect that we can achieve energy threshold level lower than or similar to that of PMTs with a rather compact system. We tested MPPC (S12573-100C)+plastic scintillator (EJ204) system in our laboratory, and succeeded in reading out 5.9 keV X-ray photons from 55Fe by operating the detector at low temperature (-10 ℃), and reading the signal with short shaping time (50 ns). We also confirmed that the light yield of our MPPC+scintillator system is comparable to the one we obtained with a conventional PMT to read scintillator signal. This indicates that it is important to reduce the noise of MPPC in order to achieve the energy threshold of 2-3 keV level. Therefore we plan to test a new MPPC such as S13360 series which has improved performance in terms of the cross talk and after-pulse. In this contribution we will report the test results and discuss future prospects.

Speaker: Tatsuya Nakaoka (Hiroshima Univ.)

19:50 Proton Single Event Effects testing of Xilinx Zynq-7010 System-on Chip

The sensitivity to radiation is dramatically increasing with the decrease in transistor dimensions and operating voltages for modern integrated circuit (IC).The low energy proton also causes single event effects through direct ionization.The System-on Chip (SoC) contains complex circuit elements in a chip. Therefore,we provided a methodology and set up a test system to measure the proton single event effects for Xilinx Zynq-7010 SoC based on 28nm technology node.The sensitivities were measured individually for five comments of Xilinx Zynq-7010 System-on Chip that include D-Cache, arithmetic logical unit (ALU), float point unit (FPU), direct memory access (DMA) and programmable logic ( PL). This methodology also was validated for a given application. The SEE sections of different blocks in different energy were calculated. The results demonstrated the D-Cache was more vulnerable than other components, such as DMA, FPU,PL and ALU for direct ionization from low energy proton. Furthermore, the cross sections of different blocks were increasing with the increase of energy except D-Cache block. The SRIM simulations provided insight into the mechanism involved.The LET values and ranges from proton and different heavy ions(Al,Mg, Na)in silicon, with an energy < 10 MeV, caculated with SRIM were given. The direct ionization form low energy leaded to upset the D-Cache, but other blocks were upset by nuclear reactions. Moreover, the experimental results were presented showing that single event functional interrupt(SEFI) was more serious than other types of single event effects.

Speaker: Xuecheng Du (Xi’an Jiaotong University)

19:51 Soft Error Evaluation and Vulnerability Analysis in Xilinx Zynq-7010 System-on Chip System

Radiation-induced soft errors are an increasingly important threat to the reliability of modern electronic systems. The System-on Chip (SoC) includes a variety of electronic components, such as CPU and SRAM. Therefore, the dependability of SoC is becoming a serious issue in operating condition. In this work, we performed the single event effect testing in Xilinx Zynq-7010 SoC chip using 241Am alpha radiation source. The Programmable Logic (PL) , Direct Memory Access (DMA), Arithmetic Logical Unit (ALU), Float Point Unit (FPU), Quad-Flash controller, D-Cache and Registers were tested and the SoC failure modes were classified the Data errors , SEFI, Time-out and System halts. The device cross sections for different components and failures in time (FIT) were calculated. Based on fault tree analysis (FTA) approach, we established fault tree and calculated the SoC failure rate in Xilinx Zynq-7010 SoC using the Isograph Reliability Workbench 11.0. The method of qualitative analysis was used to determine the unique combinations of component failures that can cause system failure and the minimal cut sets. Moreover, the risk priority numbers of different components and the risk priority numbers of different failure modes were calculated using failure mode and effects analysis (FMEA) method. The risk priority number of PL was greater than other components based on the calculated results. The results illustrated the PL was the most sensitive part of Xilinx Zynq-7010 SoC and the Quad-Flash controller was the last. The data of risk priority number of different failure modes inferred that data errors was the most crucial failure mode in Zynq-7010 SoC and the Time-out event was least failure. Throughout the above FTA and FEMA approaches, we identified the critical components and major failure modes. The vulnerability in Xilinx Zynq-7010 SoC was clearly analyzed.

Speaker: Xuecheng Du (Xi’an Jiaotong University)

19:52 Evaluation of image quality for FPD based low dose mobile C-arm CT system

The imaging quality associated with the extent of the angle of gantry rotation, the number of projection views, and the dose of X-ray radiation was investigated in flat-panel detector (FPD) based C-arm cone-beam computed tomography (CBCT) system for medical applications. A prototype CBCT system for the projection acquisition used the X-ray tube (A-132, Varian inc.) having rhenium-tungsten molybdenum target and flat panel a-Si X-ray detector (PaxScan 4030CB, Varian inc.) having a 397 x 298 mm active area with 388 μm pixel pitch and 1024 x 768 pixels in 2 by 2 binning mode. The performance comparison of X-ray imaging quality was carried out using the Feldkamp, Davis, and Kress (FDK) reconstruction algorithm with different projection acquisition conditions. In this work, head-and-dental (75kVp/20mA) and chest (90kVp/25mA) phantoms were used to evaluate the image quality. The 721 (30 fps × 24 s) projection data during 360° gantry rotation with 0.5° interval for the 3D reconstruction were acquired. Parke weighting function were applied to handle redundant data and improve the reconstructed image quality in a mobile C-arm system with limited rotation angles. The reconstructed 3D images were investigated for comparison of qualitative image quality in terms of scan protocols (projection views, rotation angles and exposure dose). Furthermore, the performance evaluation in image quality will be investigated regarding X-ray dose and limited projection data for a FPD based mobile C-arm CBCT system. [1] L. A. Feldkamp, L. C. Davis, and J. W. Kress, “Practical cone-beam algorithm,” J. Opt. Soc. Am., vol. 1(A), no. 6, pp. 612-619, 1984. [2] C.W. Seo, B.K. Cha, R.K. Kim, C.R. Kim, K. Yang, Y. huh, S. Jeon, “Development and Operation of a Prototype Cone-beam Computed Tomography system for X-ray Medical Imaging”, J. Kor. Phy. Soc., vol. 64, no. 1, pp.129-134, 2014. [3] D. L. Parker, “Optimal short scan convolution reconstruction for fan beam CT”, Med. Phys., vol. 9, no. 2, pp. 254–257, 1982.

Speaker: Dr Bo Kyuyng Cha (KERI)

19:53 X-ray performance evaluation of a wafer-scale CMOS flat panel imager for applications in medical imaging and nondestructive testing

Currently, the wafer-scale CMOS flat panel imagers have been widely used in X-ray medical imaging applications including dental CBCT, mammography as well as NDT (nondestructive testing). The CMOS active pixel sensor (APS) has many advantages such as the higher readout speed, low noise, high spatial resolution and high system integration compared to amorphous silicon TFT-based flat panel detector. Specially, the CMOS flat panel X-ray imager has the higher readout speed due to higher electrical charge mobility in single crystalline silicon. The disadvantage of current CMOS technology is the limited wafer size and less resistive to X-ray radiation damage in comparison with a-Si TFT array imager. However, the size limitation of CMOS image sensor can be solved by tiling a single panel into larger array or utilizing 12 inch-wafer scale CIS process. In this work, the 8 inch-wafer scale CMOS flat panel was fabricated using a 0.18µm 1-poly/4-metal standard CMOS image sensor (CIS) process. The CMOS APS detector with 100µm pixel size, different frame rates (30 fps in normal mode and 60 fps in binning mode) and 14.3-bit extended ADC with built-in binning mode was developed for low-dose, high resolution X-ray imaging. The various phosphor screens (or scintillators) such as Gd2O2S:Tb) and CsI:Tl with columnar structure were used in the developed CMOS flat panel detector for the X-ray photons to visible light conversion. The different scintillators and fiber-optic plate were optically combined with the CMOS sensor array to optimize the X-ray imaging characterization. The X-ray imaging performance such as X-ray sensitivity, signal to noise ratio, dynamic range and spatial resolution were measured. X-ray image with about 4.0 lp/mm spatial frequencies could be acquired. The output signal of CMOS flat panel detectors with full resolution mode linearly increased as the incident X-ray dose increases. This paper will demonstrate the significant potential of our CMOS flat panel imager for medical imaging and NDT applications with high-resolution and high-frame rate.

Speaker: Bo Kyung Cha (KERI)

19:54 Investigation of radiation dose and image quality in flat detector-based fluoroscopy and cone beam CT system

The emergence of digital flat panel detector (FPD)-based fluoroscopy and cone-beam computed tomography (CBCT) system provides real-time 2D image influoroscopy and three-dimensional (3D) visualization with sub-millimeter spatial resolution. A modern CBCT system with C-arm and closed O-arm gantry incorporating a large-area flat-panel detector is widely used as a modality for diagnosis and image-guidance in spine surgery, orthopedic and interventional suite and image guide radiation therapy. In this research, the prototype volume CT imaging platform consists of a single rotation gantry that is integrated with a cone-beam X-ray tube, filters, a collimator, an anti-scatter grid, and a large-area TFT based flat panel detector. This detector provides an active area of 400 x 300 mm2 including a 2,048 x 1,536 matrix array with 194-um pixel pitch as well as 7.5 fps and 30 fps. Scatter as the main reason limiting image quality in CBCT has been shown to reduce the contrast of soft-tissue structures, increase image noise and introduce streak artifacts. Different anti-scatter grids with a grid ratio (GR) of 8:1-12:1 with 80 line-pairs/cm and Al or carbon interspacing was used to optimize the scan protocols for specific imaging tasks such as head, thorax and abdomen surgery.The different projection images were usually acquired at various rotation angles with a constant gantry interval with a tube voltage of 80–120kVp, and different current (10–50mA) conditions. The performance evaluation of X-ray imaging quality was carried out using the FDK reconstruction algorithm through acquired 2D projection images at different gantry positions. The quantitative evaluation of image quality was investigated by using the cone beam CT phantom (QRM GmbH, Erlangen, Germany) for contrast resolution, spatial resolution, noise and modulation transfer function(MTF). The radiation dose associated with imaging task-specific protocols was investigated through acrylic CTDI head and body phantoms for central and peripheral dose measurement. The correlation between radiation dose and images quality of fluoroscopic and reconstructed 3D images were investigated for different scan protocols.

Speaker: Bo Kyung Cha (KERI)

19:55 Development and Verification of Signal Processing System of Avalanche Photo Diode for the Active Shields onboard ASTRO-H

ASTRO-H is the 6th Japanese X-ray observatory which is scheduled to be launched in 2015. Two of onboard instruments, the Hard X-ray Imager (HXI) and the Soft Gamma-ray Detector (SGD) are surrounded by large and thick BGO (Bi$_4$Ge$_3$O$_{12}$) active shields to reduce the background. Since there are large number of BGO crystals with various types of size and shape, we apply Avalanche Photo Diode (APDs) for light sensor of these BGO detectors. For the signal processing system of the BGO-APD active shield, we introduce two types of digital filter to generate trigger signals to satisfy following two requirements; anti-coincidence signal has to be generated quickly before AD conversion of the main detector starts, and also, we have to achieve lower energy threshold as much as possible. The another important issue is the trigger timing. It could be deviated due to different timing when the signals over the threshold depending on the pulse height or influence of the noise. We have optimized digital filter parameters and trigger timing including delay and width using prototype model of BGO crystals. In this year, we have finally completed to fabricate the flight model of HXI/SGD, and we have performed various measurement in the pre-flight calibrations. We have operated all of the BGO active shields at the operational low-temperature for the first time, and confirmed that our developed signal processing system works well even if they are assembled as the flight model sensors; we achieve the energy threshold of around 100 to 200 keV, which is comparable to that of obtained at the component verification test, the room background of the main detector is successfully reduced by anti-coincidence as we expected, and the trigger efficiency for the cosmic-ray event is confirmed to be almost 100%. In this contribution, we present detail of development of signal processing system of BGO-APD active shield and verification result utilizing flight model sensors.

Speaker: Masanori Ohno (Hiroshima University)

19:56 Modeling the Response Function for Soft X-ray Imager onbord ASTRO-H Satellite

The ASTRO-H satellite is the 6th Japanese X-ray astronomical observatory to be launched in FY2015. The satellite carries four kinds of detectors, and one of them is an X-ray charge-coupled device (CCD) camera, the soft X-ray imager (SXI), installed on the focal plane of an X-ray telescope. The SXI contains four CCD chips, each with an imaging area of $31\,{\rm mm}\times31\,{\rm mm}$, arrayed in mosaic, covering the whole field of view of $38’\times38’$, the widest ever flown in orbit. The CCDs are a P-channel back-illuminated (BI) type with a depletion layer thickness of $200\,$um. We operate the CCDs in a photon counting mode in which the position and energy of each photon in the energy range of $0.4-12\,$keV are measured. To evaluate the X-ray spectra obtained with the SXI, the accurate calibration of its response function is essential. For this purpose, we performed calibration experiments in Osaka University, Kyoto University, and the synchrotron facility at KEK, each with different X-ray sources with various X-ray energies. We fit the obtained spectra with 6 components; primary peak, secondary peak, constant tail, Si escape and Si fluorescence, and then model their energy dependence using physics based or empirical formulae. Since this is the first time for the P-channel BI type CCDs on the X-ray satellite, we need special care on the constant tail component which is originated in partial charge collection. We notice that we need to assume a trapping layer at the incident surface of the CCD and implemented in the response model. We also note that we have to consider detailed spectral features in the incident X-ray spectrum, even with conventional $^{55}$Fe sources, to obtain accurate response functions.

Speaker: Shota Inoue (Osaka university)

19:57 Soft X-ray quantum efficiency of X-ray CCD onboard ASTRO-H

We have developed X-ray CCD which was named Soft X-ray Imager (SXI) on onboard ASTRO-H which will launch in 2015. We employed the P-channel, back-illuminated (BI) type CCDs for SXI camera with a depletion layer thickness of 200um manufactured by Hamamatsu Photonics K.K. SXI CCD has high QE at the soft X-ray energy range below 2.0keV and thanks to its thick depletion layer, SXI enables to cover the wide X-ray energy range between 0.2-20.0keV. SXI CCD was coated with 100nm thick Al to block optical light which cause the noise for X-ray observation in space. This Al is the dead layer for BI CCD of SXI and absorbs the soft X-ray. Therefore, to determine the QE below 2keV precisely, it is necessary to measure the thickness of Al on the surface of CCD. We have carried out the measurement of QE below 2keV at the synchrotron facility in Japan, KEK photon factory. In this measurement, we employed slant incident method by changing X-ray incident angle to the X-ray CCD from 0 deg to 50 deg and compared the X-ray flux of each angle. In this paper, we will report the result of the soft X-ray QE of SXI.

Speaker: Takayoshi Kohmura (Tokyo University of Science)

Sunday, 27 September

09:00 → 12:30 Pixels (including CCD's)-2

Conveners: Hans-Gunther Moser (Max-Planck-Institut fuer Physik (Werner-Heisenberg-Institut) (D), Suen Hou (Academia Sinica (TW))

09:00 Power Dissipation Studies on n-in-n Pixel Sensors

The innermost tracking detector of the ATLAS experiment at CERN-LHC consists of planar n-in-n pixel sensors with FE-I3 front-end electronics as hybrid. Also the newly installed insertable b-layer (IBL) at the ATLAS experiment consists of pixel sensors with a revised design layout and an improved FE-I4 front-end electronics. The envisaged radiation dose in the run II data taking period of the innermost sensors will be a few $10^{15}$ Neutrons (1 MeV equivalent) cm$^{-2}$. Irradiation doses well above $10^{16}$ n cm$^{-2}$ are considered for innermost pixel detector layers in future collider and detector upgrades like the high luminosity LHC (HL-LHC). In this contribution aspects of R&D laboratory investigations employing measurements of non-irradiated and irradiated n-in-n pixel sensor structures are discussed. Main focus is a systematic study of power dissipation for n-in-n pixel sensors. Measurement parameters include variations of bulk thicknesses, sensor bias voltages, operation temperatures, and irradiation fluences.

Speaker: Reiner Klingenberg (Technische Universitaet Dortmund (DE))

150927-klingenberg.pdf

09:20 Development of n-in-p pixel modules for the ATLAS upgrade at HL-LHC

Thin planar pixel modules are promising candidates to instrument the inner layers of the new ATLAS pixel detector for HL-LHC, thanks to the reduced contribution to the material budget and their high charge collection efficiency after irradiation. 100-200 um thick sensors, interconnected to FE-I4 read-out chips, have been characterized with radioactive source scans and beam tests at the CERN-SPS and DESY. The results of these measurements will be discussed for devices before and after irradiation up to a fluence of $1.5x10^{16}$ n$_{eq}$ cm$^{-2}$. The charge collection and tracking efficiency will be compared for the different sensor thicknesses. The outlook for future planar pixel sensor productions will be discussed, with a focus on sensor design at the pixel pitches (50x50 and 25x100 µm²) foreseen for the RD53 Collaboration read-out chip in 65 nm CMOS technology. An optimization of the biasing structures in the pixel cells is required to avoid the hit efficiency loss presently observed in the punch-through region after irradiation. For this purpose the performance of different layouts have been compared in FE-I4 compatible sensors at various fluence levels by using beam test data at DESY and CERN-SPS. Highly segmented sensors will represent a challenge for the tracking in the forward region of the pixel system at HL-LHC. In order to reproduce the performance of 50x50 µm² pixels at high eta, FE-I4 compatible planar pixel sensors have been studied before and after irradiation in beam tests at high incidence angle (80º) with respect to the short pixel direction. Results on cluster shapes, charge collection and hit efficiency will be shown.

Speaker: Anna Macchiolo (Max-Planck-Institut fuer Physik (Werner-Heisenberg-Institut) (D)

Macchiolo_V1.pdf

09:40 The INFN-FBK Pixel R&D Program for HL-LHC

We report on the INFN ATLAS-CMS joint research activity in collaboration with FBK, which is aiming at the development of new pixel detectors for the LHC Phase-2 upgrades. The High Luminosity LHC will need the complete replacement of the ATLAS and CMS inner trackers with new ones fulfilling the requirements of higher radiation fluence (2x10E16 neq/cm2, or equivalently 1 Grad, expected on the inner pixel layer for 3000 fb-1 integrated luminosity), higher event pile-up (from 140 to 200 events/bunch-crossing). To reach the same or even better performance of the present system, new technologies have to be fully exploited for the redesigned Pixel detectors. Among them, the future version of front-end chips in 65-nm CMOS by the CERN RD53 Collaboration will allow for smaller pixel sizes (50x50 or 25x100 µm2) and lower thresholds (~1000 e-). The advances in the front-end design shall require sensors with smaller pixel cells and thinner active thickness to match the reduced pixel dimension and to improve track resolution and cluster separation in a higher pile-up environment. To this purpose, a new generation of 3D and planar pixel sensors with active edges are being developed in the R&D project to be fabricated at the pilot line of FBK, which was recently updated to process 6-inch wafers. The R&D program includes the design of sensors that can be readout with the present ATLAS and CMS readout chips with standard pixel pitch and also finer pitch pixels with a matching mask purposely designed on the active device. The talk will cover the main aspects of the research program, starting from the sensor design and fabrication technology, with an outlook on the future steps using both Silicon On Insulator (SOI) and Direct Wafer Bonded (DWB) wafers. A first batch of planar sensors has been already produced on DWB of two active depths (100 and 130 µm) and a few sensors have also been sent to irradiation facilities: first results from device characterization will be shown.

Speaker: Marco Meschini (Universita e INFN, Firenze (IT))

MESCHINI-HSTD10.pdf

10:00 Development of n$^+$-in-p planar pixel sensors for very high radiation environments, designed to retain high efficiency after irradiation

We have been developing planar-process pixel sensors in p-type 6-in. silicon wafer aiming for applying the pixel sensors for very high radiation environments such as high luminosity upgrade of the large hadron collider (HL-LHC). The planar process has been established well and is a cost-effective solution for the pixel sensors covering large area of a tracking detector. The p-type silicon wafer is kept as p-type after radiation damage. This fact simplifies the lithographic process only required in the side of the pixel structure and keeps the cost to be the minimum. In our previous prototype pixel sensors, we have identified locations in the pixel structure, especially under the bias rail, where we lose the efficiency for detecting passing charged particles after irradiation. Although the pixel sensor under development is a directly coupled (DC) sensor, we have implemented a biasing structure for quality assurance before bump-bonding readout chips. The new prototype sensors have been designed to mitigate the efficiency loss due to the biasing structure by re-locating the bias rail and the bias resistor, being hidden inside the area of the pixel electrode, together with other variations of the biasing structure. The new pixel sensors, thinned to 150 µm thick, have been fabricated to mate the ATLAS pixel readout ASIC, FE-I4, bumpbonded, irradiated to a fluence of 3 to 5$\times$10$^{15}$ 1-MeV neutron-equivalent (neq)/cm$^2$ at CYRIC, and evaluated with the beam of particles at CERN and DESY. The efficiencies of the different pixel structures are compared and new pixel structures are shown to have improved the efficiency greatly. The physics under the bias rail has been understood by using a semiconductor technology simulation program (TCAD). Primary author: Y. Unno Co-Authors: ATLAS-Japan Silicon Collaboration and Hamamatsu Photonics K.K.

Speaker: Yoshinobu Unno (High Energy Accelerator Research Organization (JP))

UnnoPixelJapan150927.pdf

UnnoPixelJapan150927.pptx

10:20 Performance of Edgeless Silicon Pixel Sensors on p-type substrate for the ATLAS High-Luminosity Upgrade

In view of the LHC upgrade phases towards the High Luminosity LHC (HL-LHC), the ATLAS experiment plans to upgrade the Inner Detector with an all-silicon system. The n-on-p silicon technology is a promising candidate to achieve a large area instrumented with pixel sensors, since it is radiation hard and cost effective. The presentation describes the performance of novel n-in-p edgeless planar pixel sensors produced by FBK-CMM, making use of the active trench for the reduction of the dead area at the periphery of the device. After discussing the sensor technology, some feedback from preliminary results of the first beam test will be discussed.

Speaker: Giovanni Calderini (Centre National de la Recherche Scientifique (FR))

calderini_hiroshima_2015.V5.pdf

calderini_hiroshima_2015.V5.pptx

10:40 Coffee break

11:10 AGIPD: A High Frame Rate Detector for the European XFEL

The AGIPD (Adaptive Gain Integrating Pixel Detector) collaboration - consisting of Deutsches Elektronensysnchrotron (DESY), University of Hamburg, University of Bonn and the Paul-Scherrer-Institute (PSI) - is currently developing a 2D hybrid pixel detector system capable to fulfill the requirements of the European XFEL (Eu-XFEL) that is currently being built in Hamburg (Germany) and where the first light is foreseen for the 1st January 2017. At the Eu-XFEL photons will arrive in bunch trains every 100 ms (or at a rate of 10Hz). Each train consists of 2700 bunches that arrive within 600 µs (i.e. a bunch spacing of 220 ns, meaning 4.5 MHz frame rate) followed by 99.4 ms without pulses. Each single pulse consists of 1012 X-ray photons arriving in less than 100 fs and in an energy range between 250 eV up to 25 keV. In order to cope with the large dynamic range, the first stage of each pixel in the AGIPD ASIC is a charge sensitive preamplifier with three different gain settings that are dynamically switched during charge integration. Dynamic gain switching allows to have single photon resolution in the high gain stage and to cover a large dynamic range of 104∙12.4 keV photons in the low gain stage with a linearity better than 1%. The high frame rate (4.5 MHz) requires a storage of the signal in the pixel before the readout takes place during the gap between bunch trains.The full scale chip (AGIPD1.0), received at the end of 2013, is a 64 x 64 pixel matrix. Each pixel (Area 200 x 200 µm2) is equipped with 352 storage cells. The single module system is composed by 8 x 2 AGIPD chips and the 1M system, that is actually in construction and is foreseen to be ready during summer, consists of 4 quadrants of 4 modules each, for a total of 16 modules. First measurements show that the goal of a dynamic range of 104∙12.4 keV and a noise of 270 el. has been achieved.In this presentation a general overview of the AGIPD 1M system will be given. The focus will be on the characteristics of the ASIC including first experimental results. We will present the current status and give an overview over the foreseen upgrade of the readout chip.

Speaker: Dr Xintian Shi (Paul Scherrer Institute)

11:30 Looking with a SOI monolithic pixel sensor

Silicon-On-Insulator (SOI) monolithic pixel sensor is a new imaging device which can be used for looking many kinds of invisible object, such as X-ray, charged particle, ion beam, infrared light, neutron and so on. SOI technology has many outstanding features and there were several projects to develop SOI sensors in 1990's and early 2000's. Unfortunately most of them are stopped due to difficulties in solving SOI specific issues and lack of process technology at that time. In these days, SOI technology attracts attention again as next generation semiconductor devices. From 2005 we have been developing SOI sensors process technology at KEK. The technology is based on 0.2 um SOI-CMOS process of Lapis semiconductor Co. Ltd. We have introduced several new technologies to this process and solved major problems of SOI sensor such as back-gate effect, high-resistivity wafer, cross talk between sensor and circuit, total-ionizing dose (TID) effect etc. We are now performing tens of projects for various kinds of applications and also doing a few international collaborations. I would like to describe recent status of our SOI sensor development and present applications aimed by our collaborators.

Speaker: Yasuo Arai (High Energy Accelerator Research Organization (JP))

1509HSTD10_arai_open2.pdf

11:50 First result of a Double-SOI pixel chip for x-ray imaging

Aiming at a fine pitch counting type pixel array for low energy x-ray imaging, a prototype chip based on Double-SOI process was designed and tested. The long lasting problem of crosstalk in SOI technology was solved in this chip and the single pixel test demonstrated good detection performance.

Speaker: Dr Yunpeng Lu (Institute of High Energy Physics, Chinese Academy of Sciences)

First result of a Double-SOI pixel chip for x-ray imaging.pdf

12:10 P-stop isolation study of irradiated n-in-p type silicon strip sensors for harsh radiation environment

In order to determine the most radiation hard silicon sensors for the CMS Experiment after the Phase II Upgrade in 2023 a comprehensive study of silicon sensors after a fluence of up to 1.5e15 neq/cm^2 corresponding to 3000fb-1 after the HL-LHC era has been carried out. The reuslts led to the decision that the future Outer Tracker (~20cm < R < ~110cm) of CMS will consist of n-in-p type sensors. This technology is more radiation hard but also the manufacturing is more challenging compared to p-in-n type sensors due to additional process steps in order to suppress the accumulation of electrons between the readout strips. One possible isolation technique of adjacent strips is the p-stop structure which is a p-type material implantation with a certain pattern for each individual strip. However, electrical breakdown and charge collection studies indicate that the process parameters of the p-stop structure have to be carefully calibrated in order to achieve a sufficient strip isolation but simultaneously high breakdown voltages. Therefore a study of the isolation characteristics with four different silicon sensor manufacturers has been executed in order to determine the most suitable p-stop parameters for the harsh radiation environment during HL-LHC. Several p-stop doping concentrations, doping depths and different p-stop pattern have been realized and experiments before and after irradiation with protons, neutrons and x-rays have been performed and compared to T-CAD simulation studies with Synopsys Sentaurus. The measurements combine the electrical characteristics measured with a semi-automatic probestation with Sr90 signal measurements and analogue readout. Furthermore, some samples have been investigated with the help of a cosmic telescope with high resolution allowing charge collection studies of MIPs penetrating the sensor between two strips. The conclusion on this study will be presented.

Speaker: Martin Printz (KIT - Karlsruhe Institute of Technology (DE))

Printz_HSTD_10.pdf

12:30 → 14:00 Lunch break

14:00 → 17:40 Strips

Conveners: Anna Macchiolo (Max-Planck-Institut fuer Physik (Werner-Heisenberg-Institut) (D), Olaf Steinkamp (Universitaet Zuerich (CH))

14:00 Strips and Tracker Infrastructure

TBD

Speaker: Ingrid-Maria Gregor (DESY)

Xian_Ingrid.pdf

14:30 Full-size sensor prototypes for the Phase II Upgrade of the CMS Tracker

The CMS Tracker Collaboration has designed and procured test-structures and full-size silicon strip sensor prototypes from several vendors. These productions are intended for evaluating the production quality of the manufacturers, for providing functional sensors for module prototypes and for concluding the survey towards a suitable silicon base material and sensor design. We provide an overview of the main results of the strip sensor R&D group and present first results of the recent sensor qualifications. This includes results from the first AC coupled strip sensors on 8" wafers.

Speaker: Thomas Bergauer (Austrian Academy of Sciences (AT))

Hiroshima_Xian_Bergauer_2015.pdf

14:50 Detailed Studies of Full-Size ATLAS12 Sensors

The "ATLAS ITk Strip Sensor Collaboration" R&D group has developed a second iteration of single-sided $n$-in-$p$ type micro-strip sensors for use in the tracker upgrade of the ATLAS experiment at the High-Luminosity (HL) LHC. The full size sensors measure approximately 97 x 97 mm$^{2}$ and are designed and engineered for tolerance against the 10$^{15}$ 1 MeV n$_{eq}/$cm$^{2}$ fluence expected at the HL-LHC. Each sensor has 4 columns of 1280 individual channels arranged at 74.5$\mu$m horizontal pitch. Three batches comprising of 100 unirradiated sensors, all produced by Hamamatsu Photonics, were evaluated for their mechanical, bulk and strip characteristics. Non-contact optical microscopy measurements were performed to obtain the sensor surface profile and sensor thickness. The leakage current and bulk capacitance properties were measured for each individual sensor. For sample strips across the sensor batches, the inter-strip capacitance and resistance as well as properties of the punch-through protection structure were measured. A custom-built multi-channel probecard was used to measure leakage current, coupling capacitance and bias resistance for each individual strip on every sensor. The compiled results for 100 non-irradiated sensors are presented in this paper, including summary results for over 500'000 strips probed. Results on the reverse bias voltage dependence of various parameters and frequency dependence of tested capacitances are included for validation of the experimental methods used. Where possible, results are compared with the result data delivered by Hamamatsu Photonics. It was verified that the sensors satisfy the specifications for unirradiated sensors, with almost all sensors falling well within specification.

Speaker: Bart Hommels (University of Cambridge (GB))

FullSizeATLAS12.pdf

15:10 The LHCb Silicon Tracker

The LHCb experiment is dedicated to the study of heavy flavour physics at the Large Hadron Collider (LHC). The primary goal of the experiment is to search for indirect evidence of new physics via measurements of CP violation and rare decays of beauty and charm hadrons. The LHCb detector is a single-arm forward spectrometer and includes a high-precision tracking system consisting of a silicon-strip vertex detector surrounding the proton-proton interaction region, a large-area silicon-strip detector located upstream of a dipole magnet, and three stations of silicon-strip detectors and straw drift tubes placed downstream of the magnet. The silicon-strip detectors located upstream and downstream of the magnet, the Tracker Turicensis (TT) and the Inner Tracker (IT), collectively form the LHCb Silicon Tracker (ST). The TT covers the full acceptance before the magnet while the IT covers a cross-shaped region in the region of highest particle density around the beam-pipe downstream of the magnet. The design of the ST was presented at previous ``Hiroshima'' symposia. The performance and operation of the Silicon Tracker during LHC Run 1 will be reviewed. The maintenance and operation of the detectors during the two year shutdown of the LHC will be discussed and the various repairs and improvements that have been made to the detector hardware and software will be shown. Finally, the re-commissioning of the detector for LHC Run 2 and first results on the performance of the detector will be presented. In particular, the latest measurements of the observed radiation damage will be shown and compared to that expected from simulation.

Speaker: Mark Tobin (Ecole Polytechnique Federale de Lausanne (CH))

MTobin_HSTD10.pdf

15:30 Tea break

16:00 Charge collection and field profile studies in heavily irradiated silicon strip sensors for the ATLAS Inner Tracker Upgrade

The ATLAS group has evaluated the charge collection in silicon microstrip sensors irradiated up to fluence of 1$\times$10$^{16}$ n$_{\rm eq}$/cm$^2$, exceeding the 1.6$\times$10$^{15}$ n$_{\rm eq}$/cm$^2$ maximum expected during the HL-LHC period including a safety factor of 2. The ATLAS12, n$^+$-on-p type sensors fabricated by HPK on FZ substrates, is the latest barrel sensor design. The charge collection out of irradiated 1×1 cm2 barrel test sensors has been evaluated systematically using penetrating -rays and Alivaba readout systems. The obtained data are compared among various measurement sites and with previous ATLAS07 design. The results are very consistent particularly when the sensor thicknesses are normalized with the active thickness derived from CV and edge-TCT (Transient Current Technique) measurements. The edge-TCT is also effective in evaluation of the field profiles across the depth and differences have been examined between irradiated ATLAS07 and ATLAS12 samples and among the samples irradiated with different radiation sources, neutrons, protons and pions. The studies of the bulk properties of the devices show that they can yield sufficiently large signal for the expected range of fluence in the HL-LHC to remain precision tracking sensors. The presentation is on behalf of the ATLAS ITK Strip Sensor Collaboration

Speaker: Kazuhiko Hara (University of Tsukuba (JP))

Hiroshima_CCE_hara_final.pdf

Hiroshima_CCE_hara_final.pptx

16:20 Investigation of HV/HR-CMOS technology for the ATLAS Phase-II Strip Tracker Upgrade

ATLAS has formed strip CMOS project to study the use of CMOS MAPS devices silicon strip sensors for the Phase-II Strip Tracker Upgrade. This choice of sensors promises several advantages over the conventional baseline design, such as better resolution, less material in the tracking volume, and faster construction speed. At the same time, many design features of the sensors are driven by the requirement of minimizing the impact on the rest of the detector. Hence the target devices feature long pixels which are grouped to form a virtual strip with binary-encoded z position. The key performance aspects are radiation hardness compatibility with HL-LHC environment, signal timing resolution compatibility with bunch crossing period of 25 ns, as well as extraction of the full hit position with full-reticle readout architecture. To date, several test chips have been submitted using two different CMOS technologies. The AMS 350 is a HV-CMOS process, which features the sensor bias of up to 120 V. The TowerJazz 180 nm HR-CMOS process uses a high resistivity epitaxial layer to provide the depletion region on top of substrate. We have evaluated charge collection, output signal timing, gain and noise of these chips. The results strongly support the radiation tolerance of these devices to radiation dose of the HL-LHC in the strip tracker region (60 Mrad and 2x10^15 neq/cm^2). We will also describe our next chip designed as a full-reticle length sensor for prototyping the readout architecture and to investigate large-chip effects, such as common mode noise. The hit encoding engine is capable of reading out up to 8 hits from a pre-defined region. The hits are then transferred off-sensor via high-speed bus to reduce the wirebond count. Placement of the comparators and the bulk wafer resistivity will be varied to find the optimal performance.

Speaker: Vitaliy Fadeyev (University of California,Santa Cruz (US))

CMOS-HSTD10-Xian_2015-09-27_v4p1.pdf

16:40 Study of Surface Properties of ATLAS12 Strip Sensors and their Radiation Resistance

on behalf of the ATLAS ITk Strip Sensor Collaboration A radiation hard *n*-in-*p* micro-strip sensor for the use in the Upgrade of the strip tracker of the ATLAS experiment at the High Luminosity Large Hadron Collider (HL-LHC) has been developed by the “ATLAS ITk Strip Sensor collaboration” and produced by Hamamatsu Photonics. Surface properties of different types of end-cap and barrel miniature sensors of the latest sensor design ATLAS12 have been studied before and after proton and gamma irradiation. The tested barrel sensors vary in “punch-through protection” (PTP) structure; while the end-cap sensors having stereo-strips in fan geometry differ also in strip pitch, in stray strip ganging and in fan geometry. Sensors have been irradiated with cyclotron protons at University of Birmingham (UK), at Karlsruhe Inst. Tech. (Germany) and at CYRIC, Tohoku University (Japan) up to fluence of 1E16n$_e$$_q$/cm$^2$ and by gamma in BNL (USA) up to dose of 100kGy. The main goal of presented study was to characterize the leakage current for micro-discharge breakdown voltage estimation, the inter-strip resistance and capacitance, the bias resistance and the effectiveness of PTP structure as a function of bias voltage and fluence. It has been verified that the ATLAS12 sensors have high breakdown voltage well above the operational voltage which implies that different geometries of sensors do not influence their stability. The interstrip isolation is a strong function of irradiation fluence, however the sensor performance is acceptable in the expected range for HL-LHC. New gated PTP structure exhibits low PTP onset voltage and sharp cut-off of effective resistance even at the highest tested radiation fluence. The inter-strip capacitance complies with the technical specification required before irradiation and no radiation-induced degradation was observed. A summary of ATLAS12 sensors test will be presented including a comparison of results from different irradiation sites. The measured characteristics will be compared with ATLAS07 sensor design.

Speaker: Marcela Mikestikova (Acad. of Sciences of the Czech Rep. (CZ))

HSTD10_Suface studies270915.pdf

17:00 Silicon sensor study for the forward strip tracker of the ATLAS experiment for the HL-LHC

R. Mori on behalf of the ATLAS ITK Strip Sensor community The upgrade to the High Luminosity LHC foreseen in about ten years represents a great challenge for the ATLAS inner tracker and the silicon strip sensors in the forward region which have to sustain a radiation fluence up to 2*10^15 n_eq/cm^2. Several strip sensor designs have been developed by ATLAS and fabricated by Hamamatsu in order to maintain enough performance in terms of charge collection efficiency and its uniformity throughout the active region. Of particular attention, in case of a stereo-strip sensor, is the area near the sensor edge where shorter strips have been ganged to the full ones. In this work we present the electrical and charge collection test results on miniature sensors with forward geometry irradiated with protons at different sites. The irradiated devices were tested systematically before, after irradiation and after annealing at 60°C for 80 min. The I(V) and C(V) measurements results demonstrate reasonable full depletion voltages and current levels. Results from charge collection efficiency measurements show that at the maximum expected fluence, the collected charge is roughly halved with respect to the one obtained prior to irradiation. However, it is still high in comparison with the expected noise level. No significant difference between different sensor layouts has been observed. Laser measurements show a good signal uniformity over the sensor. Uniform charge collection between different strips and along the strip direction has been observed and the ganged strips have a similar efficiency as full strips. Only a small difference has been seen between the different ganging techniques, the DC ganging collecting slightly more as the AC ganging. Both studies indicate good performance of the forward strip sensors for the ATLAS upgrade.

Speaker: Riccardo Mori (Albert-Ludwigs-Universitaet Freiburg (DE))

Mori-talkHiroshima-201509-Strip_sensor_forward_detector.pdf

17:20 Sensors from Infineon Technologies AG: Status, capabilities and plans

Speaker: Johannes Hacker (u)

2015-09-27-Sensors-from-Infineon-Technologies.pdf

18:30 → 20:30 Symposium Dinner

Convener: Qingmin Zhang (XJTU)

SymposiumDinnerSeatingV2_SortedNames.pdf

Monday, 28 September

09:00 → 11:10 New Materials, New Technologies, Radiation Damage, Environmental Monitoring, Applications in Space

Convener: Kazuhiko Hara (University of Tsukuba (JP))

09:00 The Si/CdTe Semiconductor Camera of the ASTRO-H Hard X-ray Imager (HXI) (including an brief overview of semiconductor devices on satellites)

The Hard X-ray Imager (HXI) is one of the instruments onboard ASTRO-H, which is scheduled for launch in 2015. The HXI is placed 12 m below the hard X-ray focusing mirrors, and performs imaging spectroscopy with the sensitivity for detecting point sources down to a brightness of 1/100,000 times fainter than the Crab nebula at > 10 keV. The semiconductor camera in the HXI is realized as a stacked semiconductor detector system, which consists of silicon and cadmium telluride (CdTe) sensors. The flight model of the HXI camera has been fabricated and installed on the satellite. The sensor head has dimensions of 10 cm x 10 cm x 4 cm, consisting of 4 layers of Si and CdTe double-sided strip detectors, and front-end readout electronics. Adopting the cross-strip electrode configuration for Si/CdTe sensors, no inactive materials are required between the detectors. This multi-layer approach provides high detection efficiency up to 80 keV, and ensures a high sensitivity free from the activation background below 40 keV. The strip pitch of the Si/CdTe sensors is 0.25 mm, and the signals from all 1280 strips are processed by 40 ASICs developed for the HXI. In this contribution, we present the final design of the HXI camera, and results from the performance verification tests.

Speaker: Dr Goro Sato (ISAS/JAXA)

09:30 A pascalian later drift detector

The necessity for detectors with improved spatial resolution drives many silicon detector R&D projects towards small pitch sizes in various areas of research. However, the evolutionary approach of reduced pitch size increases the number of channels and thus needed bandwidth for detector read-out. A new detector concept, a Pascalian later drift detector (pLAD), exemplifying a strategy for high precision silicon sensors is introduced in this talk that avoids the small pitch dogma and decouples the sensor resolution from the pitch size. The scheme of this new technology is introduced and simulation results are presented exemplifying the feasibility of the working principle.

Speaker: Hendrik Jansen (Deutsches Elektronen-Synchrotron Hamburg and Zeuthen (DE))

2015_09_28_HSTD20-Xian_v2.pdf

09:50 Radiation-Hard/High-Speed Parallel Optical Engine

The LHC at CERN is now the highest energy and luminosity collider in the world. The collider and detectors have just completed an upgrade to operate at higher energy and luminosity. In addition, there are plans to further upgrade the collider and detectors to operate at even higher energy and luminosity. This requires the optical links to transmit data at much higher speed to handle the much increased luminosity. We will present the results from the just completed optical link upgrade for the pixel detector of the ATLAS experiment and the future R&D project. For the completed upgrade, we designed and produced new radiation-hard/high-speed parallel optical engine for the upgraded pixel detector. The new fiber optic transceivers, opto-boards, were designed and produced to replace the first generation opto-boards installed on the ATLAS pixel detector and for the new pixel layer. Each opto-board contains one 12-channel PIN array and two 12-channel VCSEL arrays along with associated receiver/driver ASICs. The new opto-board design benefits from the first generation production and operational experience and contains several improvements. The new opto-boards have been installed. We will present the design, production and operational experience, and reliability study of the new opto-boards. For the future upgrade, we design an ASIC that contains an array of 4 high-speed/radiation-hard drivers to operate an array of 4 VCSELs (Vertical Cavity Surface Emitting Lasers). The bandwidth of each driver is 10 Gb/s. The plan is to increase the number of channels to 12 channels. With the spacing of 250 μm between two VCSELs, the width of an optical array is only 3 mm. This allows the deployment of a compact 120 Gb/s parallel optical engines at a high radiation location close to the interaction region where space is at a premium. We will present the result from the 4-channel driver ASIC fabricated with 65 nm CMOS process. We have also designed a new opto-board that couples the ASIC to an VCSEL array. The result from the new high-speed optical engine will be presented together with the future plans.

Speaker: K.K. Gan (The Ohio State University (US))

HSTD10_Gan.pdf

10:10 The edge transient-current technique (E-TCT) with high energy hadron beam

We propose a novel method to investigate the properties of silicon and CVD diamond detectors for High Energy Physics experiments. The method is similar to the already well established E-TCT technique using laser beam. In the proposed method the beam of high energy hadrons (MIPs) is used instead of laser beam. MIPs incident on the detector in the direction parallel to the readout electrode plane and perpendicular to the edge of the detector. Such experiment could prove very useful to study CVD diamond detectors which are almost inaccessible for the E-TCT measurements with laser due to large band-gap as well as to verify and complement the E-TCT measurements of silicon. In our current setup the DUT is connected to a Particulars high bandwidth current amplifier and recorded by a PSI developed DRS oscilloscope. The readout is triggered by a passage of the MIP through 2 scinitllators coupled to PMTs. The trajectory of each MIP is accurately measured by a reference telescope so the waveforms can be associated with track that released charge at known depth of the DUT. Since the MIP is traversing the detector parallel to the electrodes it releases by an order of magnitude larger charge then in the normal incidence therefore providing large signals. Noise can be further suppressed by averaging waveforms associated to tracks traversing the selected part of the DUT. The method proposed is being tested at CERN in a beam of 120GeV hadrons using a Kartel telescope based on Mimosa 26 sensors with track resolution at the DUT of few μm. MIPs passing trough 6 planes of the reference telescope with the DUT detector in the middle are triggered by 2 scintillators. The preliminary results of the measurements will be presented.

Speaker: Andrej Gorisek (Jozef Stefan Institute (SI))

HSTD10.pdf

10:30 Drift Mobility and Electric Field in Silicon Detectors Irradiated with Neutrons and Protons up to 1E17 n_eq/cm^2

Electric field in silicon irradiated with neutrons up to 1e17 n_eq/cm^2 was investigated by edge-TCT. Methods for absolute determination of electric field were developed. From the v(E) dependence mobility degradation with fluence was extracted. A simple field structure was observed, consistent with a SCR and "ENB", a region that does not contribute to leakage current and the electric field there is consistent with current transport across highly resistive silicon. The observed mobility change and the values of electric field indicate substantial reduction of trapping from linear extrapolation of low fluence values. An irradiation campaign at CERN IRRAD covering the fluence range from 3e14 n_eq/cm^2 to 3e16 n_eq/cm^2 shall provide complementary information on electric field and mobility changes after charged hadron irradiation.

Speaker: Marko Mikuz (Jozef Stefan Institute (SI))

HSTD-10-mm.pdf

10:50 Performance of silicon pixel detectors at small track incidence angles

In order to enable the ATLAS experiment to successfully track charged particles produced in high-energy collisions at the High-Luminosity Large Hadron Collider, the current ATLAS Inner Detector will be replaced by the Inner Tracker (ITk), entirely composed of silicon pixel and strip detectors. An extension of the tracking coverage of ITk to very forward pseudorapidity values is proposed, using pixel modules placed in a long cylindrical layer around the beam pipe. The measurement of long pixel clusters, detected when charged particles cross the silicon sensor at small incidence angles, has potential to significantly improve the tracking efficiency, fake track rejection, and resolution of ITk in the very forward region. The performance of state-of-the-art pixel modules at small track incidence angles is studied using test beam data collected at SLAC and CERN, as well as simulated data.

Speaker: Simon Viel (Lawrence Berkeley National Lab. (US))

sviel_HSTD_sep29.pdf

11:10 → 12:10 Lunch break

Convener: Qingmin Zhang (XJTU)

12:30 → 19:30 Excursion (The Terracotta Worriers and Horses + Huaqing Palace: 450 RMB/person (payment at on-site registration)

Convener: Qingmin Zhang (XJTU)

12:30 Take the bus in front of the hotel

13:30 Visit the Museum "The Terracotta Worriers and Horses"

16:00 Take the bus to go to “The Huaqing Palace Heritage Site”

16:40 Visit the Huaqing Palace

18:10 Meet and go back downtown of Xi’an city

19:30 → 20:30 Dinner (Eat together)

20:30 → 21:30 After dinner POSTER session, with drinks: (All presenters are requested/encouraged to attend their posters; All participants are requested to participate the session, with drinks!)

Conveners: Marcela Mikestikova (Acad. of Sciences of the Czech Rep. (CZ)), Stephen Mcmahon (STFC - Rutherford Appleton Lab. (GB))

Tuesday, 29 September

09:00 → 12:30 Electronics, Applications in Medical Science, Applications in High Energy Physics

Conveners: Jaakko Harkonen, Vitaliy Fadeyev (University of California,Santa Cruz (US))

09:00 A novel method for estimating the 3-D distribution of radioactive isotopes in the material

In recent years, various gamma-ray visualization techniques (gamma camera) have been proposed. These techniques are extremely effective for identification of “hot spots,” i.e., regions where radioactive isotopes accumulate in nuclear disaster-affected areas in Fukushima and around a nuclear reactor. However, the images acquired with a gamma camera do not include the distance information between radioactive isotopes and the camera and hence are “degenerate” in the direction of the isotopes. Moreover, depth information in the images is lost when isotopes are embedded in materials, such as water, sand, and concrete. Here, we propose two novel methods of obtaining depth information of radioactive isotopes embedded in materials by comparing (1) their spectra and (2) the images of incident gamma rays scattered by the materials and direct gamma rays. In the first method, spectra of radioactive isotopes and the ratio of scattered to direct gamma rays are obtained. We verify experimentally that the ratio increases with increasing depth, as predicted by simulations. In the second method, the spatial extent of images obtained for direct and scattered gamma rays is compared. By performing detailed simulations using Geant4, we verify that the spatial extent of the position where gamma rays are scattered increases with increasing depth. For demonstration, we are developing various gamma cameras to compare low-energy (scattered) gamma-rays images with a fully photo-absorbed gamma-ray image. We also demonstrate that the 3-D reconstruction of isotopes/hotspots is indeed possible with our proposed methods. These methods have potential applications in the medical field and in severe environments such as disaster-affected areas in Fukushima.

Speaker: Mr Yasuhiro Iwamoto (Waseda University)

HSTD10_iwamoto.pdf

09:20 Development of Scintillator Readout System with MPPC for Potable Compact Gamma-ray Spectrometer

After the Fukushima Daiichi nuclear accident, the public necessity increases to measure and identify the radioactive isotopes from the environment. Although Ge detectors are powerful with the high energy resolution, it is too expensive (and heavy) to be used widely. Therefore, we developed an inexpensive portable compact gamma-ray spectrometer with the combination of CsI(Tl) scintillator and Multi-Pixel Photon Counter (MPPC) detector, a silicon photomultiplier developed by Hamamatsu Photonics. In this paper, we present (1) how we chose the sizes of CsI(Tl) and MPPC, (2) the development of the feedback circuit to keep the MPPC gain stable against the temperature variation, and the calibration of the spectrometer at Facility of Radiation Standards of Japan Atomic Energy Agency, and (3) some example of actual environment measurements. Among many photon readout detectors, MPPC, photo-multiplier, photo-diode, avalanche photo-diode, we chose the 6 x 6 mm2 MPPC according to the high quantum efficiency, small detector size, light weight, and low operational high voltage. CsI(Tl) scintillator was selected from the relatively high stopping power with the low price. The size of CsI(Tl) crystal was determined as large as 1-inch cubic to identify 137Cs and 134Cs lines (667 keV and 605 keV) separately with keeping the energy resolution better than 8% at 662 keV (FWHM). There is small deviation (~7%) from the linear correlation between the gamma-ray energy and output pulse height above ~1 MeV. It is reasonable due to the pileup effect of some photons into one pixel, since the number of CsI(Tl) scintillation photons is 56000/MeV with the decay time constant of ~1 us. The temperature dependence of MPPC gain was measured for 10 units of 1-inch cubic CsI(Tl) and MPPC. The results show that there is almost no difference about the slope of the relation, while the offset changes for unit by unit. The spectrometer includes the feedback circuit of the high voltage with temperature monitor.

Speaker: Hiromitsu Takahashi (Hiroshima University)

hstd10_mppc.pdf

09:40 A High Frame Rate Pixel Chip Design for Synchrotron Radiation Applications

A hybrid pixel detector working in the single photon counting mode was designed for the High Energy Photon Source (HEPS) in China. Aiming for diffraction and protein crystallography applications, the pixel readout chip works in single photon counting mode in each pixel. It contains an array of 104 × 72 pixels with a pixel size of 150µm×150µm, each owning a counting depth of 20bit. Different from the conventional readout structure based on linear feedback shift register chain, an independent shift register chain was inserted, separated with the counter. Then a 20MHz readout clock can simply increased the frame rate up to 1kHz. By reusing this chain to refresh the configuration data at the same time while data is being readout, the conventional triple-redundancy latches can also be eliminated concerning the SEU events. The measurement showed 118e- equivalent noise after bump bonding and non-uniformity less than 55e- after threshold equalization. All functionalities were proved to be normal at a frame rate of 1.2kHz with a dead-time less than 175ns/frame, which are greatly improved compared with the existing pixel system.

Speaker: Jie Zhang (Institute of High Energy Physics, Chinese Academy of Sciences)

A High Frame Rate Pixel Chip Design for Synchrotron Radiation Applications.pdf

10:00 A 2D imager for X-ray FELs with a 65 nm CMOS readout based on per-pixel signal compression and 10 bit A/D conversion

The unprecedented features of X-ray free electron lasers, capable of producing photon pulses with outstanding brightness and ultra-short duration, promise to revolutionise a number of research fields, including structural biology and chemistry, material science and nuclear and molecular physics. Specific instrumentation needs to be designed and fabricated to comply with the demanding specifications of the most challenging experiments at FELs, such as coherent X-ray diffraction imaging of non-periodic structures, also depending on the beam characteristics: wide dynamic range, single photon resolution at small signals, fast operation rate, minimum dead area, small pitch, radiation tolerance. The PixFEL project, funded by Istituto Nazionale di Fisica Nucleare, is the first step of a long term program aiming at building a large area, focal plane detector based on an active edge sensors interconnected to a dual layer front-end chip with onboard memory. The PixFEL collaboration is developing the main microelectronic blocks for the instrument, while exploring the enabling technologies for the final assembly. Active edge and slim edge pixel detectors have been simulated, designed and optimised for operation with X-rays in the 1 to 10 keV range, also accounting for potential plasma effects due to the large amount of energy released in the detector substrate. A first batch has been submitted, including test structures and arrays of pixels with splittings on pixel pitch and active edge termination. To read the signal from the detector, a front-end channel, compatible with a pitch of 110 um, has been designed in a 65 nm CMOS technology. Compliance with the 80 dB dynamic range typical of diffraction imaging experiments is achieved by means of a low noise preamplification stage with dynamic signal compression capabilities. Time-variant shaping is provided by a switched capacitor filter performing correlated double sampling. A low power, small area SAR ADC converts the analog sample to a 10 bit word. Promising results have been obtained from the characterisation of the test structures, including single blocks, full channels and an 8x8 array. The presentation will introduce the project, present the main test results and discuss the next steps.

Speaker: Lodovico Ratti (Universita e INFN, Pavia (IT))

HSTD10_ratti.pdf

HSTD10_ratti.pptx

10:20 Perspective of 65 nm CMOS technology for radiation-tolerant electronics in high energy physics

Due to the possibility of offering stronger data processing ability, 65 nm CMOS technology is being studied for the perspective of replacing the widely used 130 nm CMOS technology in CERN Large Hadron Collider (LHC). For electronics working under High Energy Physics (HEP) environments, the target has now been raised up to 1 Grad(SiO2) for the electronics in the LHC upgrade, which is the estimated deposited dose in 10 years after upgrade. Besides of that, it has been reported in 130 nm transistors that the heavy ion strike may induce the soft breakdown of the gate oxide, and then the driving currents of the transistors were highly reduced. It is not certain that if 65 nm transistors can successfully overcome these threats, and the suitability of this technology to the extreme HEP environments has to be evaluated. In this paper, the radiation tolerance of a commercial 65 nm technology was verified by 3 MeV protons and heavy ions, to evaluate the long-term degradation and the possible existence of the micro-dose effect correspondingly. From the irradiation results, the 65 nm CMOS transistors showed severe long-term degradation especially in the drain saturation current. The good news is that the transistors did not behave any sudden loss of driving current even after multiple strikes of heavy ions at the gate oxide.

Speaker: Dr Lili Ding (State Key Laboratory of Intense Pulsed Radiation Simulation and Effect, Northwest Institute of Nuclear Technology, China; Department of Information Engineering, Padova University, Italy)

10:40 Coffee break

11:10 First demonstration of real-time gamma imaging by using a handheld Compton camera for particle therapy

Real-time gamma imaging during particle therapy is expected to improve the accuracy of the therapy. A Compton camera is a promising detector for online monitoring during the particle therapy because it is capable of conducting measurements across a wide energy range, measuring not only the annihilation gamma rays (511 keV) but also a part of the prompt gamma rays. In this study, we demonstrated the imaging of gamma rays generated by the nuclear interactions during proton irradiation by using a handheld Compton camera ${\rm ( 14\ cm \times 15\ cm \times 16\ cm ,\ 2.5\ kg )}$ based on scintillation detectors. The angular resolution of this Compton camera is ${\rm \sim 8 ^{\circ}(FWHM)}$ for a ${\rm ^{137}Cs}$ source. We used the cyclotron at the National Institute of Radiological Sciences (NIRS) in Japan, which can generate a 70 MeV proton pencil beam. We measured the energy spectra of the gamma rays using a ${\rm LaBr_3}$(Ce) scintillator and photomultiplier tube (PMT) and performed image reconstruction using the handheld Compton camera when using the proton beam to irradiate the water, ${\rm Ca(OH)_2}$, and PMMA phantom. In the energy spectrum of the PMMA phantom, we found the obvious peak at not only 511 keV but also 718 keV, a part of the prompt gamma rays that derived from ${\rm ^{10}C}$. Therefore, we evaluated the peak positions of the projection of the reconstructed images using both of them. This evaluation showed that the peak positions are 23 $\pm$ 1.8 mm and 30 $\pm$ 8.1 mm, respectively, while the Bragg peak position calculated by simulation is 33mm. We cannot arrive at a clear conclusion that prompt gamma rays trace the Bragg peak well from these results, because of the uncertainty by the spatial resolution of the Compton camera. We can acquire online gamma imaging of both of the energy ranges during proton irradiation in a short time. We are going to develop a high-resolution Compton camera in the near future.

Speaker: Mr Takanori Taya (Waseda University)

HSTD10_taya.pdf

11:30 A compact silicon pixel based PET detector with ATLAS Phase-II-like sensors

Positron emission tomography (PET) is a powerful medical imaging method, which requires a precise measurement of two coincident low energy photons, with great spatial and time resolution. We present a plan to build a novel compact PET detector system based on pixel silicon detectors developed for ATLAS Phase-II upgrade which will achieve. A time resolution of the order of 30 ps for optimal contrast images and a total thickness of the order of cm allow the detector to be operated inside and at the same time of an MRI scanner. The performance of the detector will allow for a spatial resolution of a few millimeter on the photon source.

Speaker: Alberto Cervelli (Universitaet Bern (CH))

Hiroshima.pdf

11:50 Proton Tracking for Medical Imaging and Dosimetry

For many years, silicon micro-strip detectors have been successfully used as tracking detectors for particle and nuclear physics experiments. A new application of this technology is to the field of particle therapy where radiotherapy is carried out by use of charged particles such as protons or carbon ions. Such a treatment has been shown to have advantages over standard x-ray radiotherapy and as a result of this, many new centres offering particle therapy are currently under construction around the world today. The characteristics of a new silicon micro-strip detector based system for this application will be presented. The array uses specifically designed large area sensors in several stations in an x-u-v configuration to be suitable for very fast proton tracking with minimal ambiguities. The sensors will form a tracker capable of giving information on the path of ~200 MeV protons entering and exiting a patient allowing proton computed tomography (pCT) to aid the accurate delivery of treatment dose with tuned beam profile and energy. The tracker will also be capable of proton counting and position measurement at the higher fluences and lower energies used during treatment allowing monitoring of the beam profile and total dose. First results from the tracking stations will be presented along with details of the readout electronics together with simulation work from GEANT4. Radiation tests and studies completed with a 36 MeV beam at the University of Birmingham Cyclotron, UK, and a 62 MeV proton beam at the Clatterbridge Cancer Centre, UK will be shown as well as preliminary measurements with higher energy proton beams at the iThemba LABS in South Africa.

Speaker: Jon Taylor (University of Liverpool)

HSTD10_JTaylor.pdf

12:10 The LHCb Upstream Tracker Project

The LHCb detector performs searches for New Physics in CP-violating observables and rare heavy-quark decays at the LHC. A comprehensive upgrade is planned for the long shutdown of the LHC in 2018/19. A goal of this upgrade is to abolish hardware triggers and read out the full detector at 40 MHz. This requires to replace the existing TT station upstream of the LHCb magnet by a new silicon micro-strip detector, the Upstream Tracker (UT). The UT will have a new front-end chip compatible with 40 MHz readout, silicon sensors with improved radiation hardness, finer readout granularity, and improved acceptance coverage at small polar angles. The outer region of each detection layer will be covered by p-in-n sensors with 10 cm long strips and a pitch of about 180 mum, while n-in-p sensors with half the pitch and strip length will be employed in the regions of highest particle density close to the beam pipe. The innermost sensors will have a circular cutout to optimize the forward acceptance. The front-end chip is being developed in 130 nm TSCM technology and embeds front-end amplifiers, shapers and ADCs as well as pedestal subtraction, common-mode suppression and sparsification. Cooling of the silicon sensors and front-end chips and is provided by bi-phase CO$_2$. I will motivate the main UT design choices and show first results from tests of prototype readout chips and silicon sensors and from mechanical and cooling tests.

Speaker: Olaf Steinkamp (Universitaet Zuerich (CH))

HSTD10_150929_OlafSteinkamp.pdf

12:30 → 14:00 Lunch break

Convener: Qingmin Zhang (XJTU)

14:00 → 15:30 Applications in High Energy Physics

Convener: Xinchou Lou (University of Texas at Dallas (US))

14:00 Diamond Sensors for Future High Energy Experiments, including Testbeam Results of 3D Diamond Sensor

With the recent turn-on of the LHC at 13TeV, ATLAS and CMS are planning to upgrade their innermost tracking layers with more radiation hard technologies. Chemical Vapor Deposition (CVD) diamond is one such technology. CVD diamond has been used extensively in beam condition monitors as the innermost detectors in the highest radiation areas of BaBar, Belle, CDF and all LHC experiments. This talk will describe the lessons learned in constructing the ATLAS Beam Conditions Monitor (BCM) and ATLAS Diamond Beam Monitor (DBM) both of which are based on CVD diamond with the goal of elucidating the issues that should be addressed for future diamond based detectors. The talk will also discuss the present status of state-of-the-art polycrystalline and single-crystal CVD diamond and the latest results on the radiation tolerance of the highest quality material for a range of proton energies, pions and neutrons obtained with this material.

Speaker: Felix Caspar Bachmair (Eidgenoessische Tech. Hochschule Zuerich (CH))

DiamondSensorsForFutureHighEnergyExperiments_upload.pdf

DiamondSensorsForFutureHighEnergyExperiments_upload.pdf

DiamondSensorsForFutureHighEnergyExperiments_upload.pptx

14:30 The DAMPE silicon tungsten tracker

The DArk Matter Particle Explorer is a spaceborne astroparticle physics experiment, programmed for launch on December 2015. It is one the five satellites of the Chinese Academy of Science (CAS) “Strategic Pioneer Research Program in Space Science” program. DAMPE will identify possible dark matter signatures by detecting electrons and photons in the 5 GeV – 10 TeV energy range. It will also measure the flux of nuclei up to 100 TeV, for the study of the high energy CR origin and propagation mechanisms. DAMPE is composed of four sub-detectors: a plastic strip scintillator, a silicon-tungsten tracker-converter (STK), a BGO imaging calorimeter and a neutron detector. The STK is composed of six tracking planes of 2 orthogonal layers of single-sided microstrip detectors, for a total detector surface of ca. 7 m$^2$. Three 1mm-thick layers of tungsten are interleaved with the tracking planes for the photon conversion. Two models of the STK have been produced, one for the space qualification tests (EQM), and one for the space mission (FM). The EQM has been assembled and tested in 2014, while the FM has been assembled and acceptance tested from January to June 2015. The STK has been extensively tested for space qualification. Numerous beam tests at CERN have been done to study particle detection at silicon module level, and at full detector level. To complete the knowledge on the detector performance, simulation studies are conducted. The assembly, space qualification and characterization tests of the STK, as well as the status of simulation studies of the silicon detectors will be presented.

Speaker: Philipp Azzarello (Universite de Geneve (CH))

DAMPE_STK_HSTD10_v1r3.pdf

14:50 Vertex and tracking detector R&D for CLIC

The physics aims at the future CLIC high-energy linear e+e- collider set very high precision requirements on the performance of the vertex and tracking detectors. Moreover, these detectors have to be well adapted to the experimental conditions, such as the time structure of the collisions and the presence of beam-induced backgrounds. The principal challenges are: a point resolution of a few micron, ultra-low mass (~0.2% X0 per layer for the vertex region and ~1% X0 per layer for the outer tracker), very low power dissipation (compatible with air-flow cooling in the inner vertex region) and pulsed power operation, complemented with ~10 ns time stamping capabilities. A highly granular all-silicon vertex and tracking detector system is under development, following an integrated approach addressing simultaneously the physics requirements and engineering constraints. For the vertex-detector region, hybrid pixel detectors with ultra-small pitch (25 um) and analogue readout are explored. For the outer tracking region both hybrid concepts and fully integrated sensors are under consideration. Recent R&D achievements include results from beam tests with prototypes of a novel hybridisation concept based on capacitive coupling between active HV-CMOS sensors and CLICpix readout ASICs implemented in 65 nm CMOS technology. Simulations based on Geant4 and TCAD are used to validate the experimental results and to optimise the detector designs. An overview of the R&D program for pixel and tracking detectors at CLIC will be presented.

Speaker: Dominik Dannheim (CERN)

vtx_trk_detector_RD_for_CLIC_Hiroshima2015_29Sep2015.pdf

15:10 Vertex Detector for the CEPC: A Prospective Overview

The Circular Electron Positron Collider (CEPC) has been proposed by the Chinese High Energy Physics Community to operate as a Higgs Factory, which allows precision measurements of the properties of the discovered Higgs particle. The CEPC vertex detector, which will be placed closest to the interaction point, must fulfill the stringent performance requirements on high spatial resolution, low material budget, low power consumption, high radiation tolerance, etc. In this presentation, I will give an overview of such requirements and also discuss the potential sensor technologies as well as possible challenges on the mechanics and cooling. I will also report briefly the layout optimization work and progress on several R&D topics.

Speaker: Hongbo Zhu (Chinese Academy of Sciences (CN))

CEPC_overview_ZHU.pdf

15:30 → 15:50 Closing of the Symposium

Convener: Xinchou Lou (University of Texas at Dallas (US))

15:30 Closing Remarks

Speaker: Hartmut Sadrozinski (SCIPP, UC santa Cruz)

Final_remarks_HSTD10.pptx

17:20 → 19:50 Entertainment and Dinner (Chang-an Show + Dumplings Dinner): 350 RMB/person, payment at on-site registration