# The 26th International Workshop on Vertex Detectors

Hotel Enclave Las Caldas, Asturias, Spain
Description

The International Workshop on Vertex Detectors (VERTEX) is a major annual series of international workshops for physicists and engineers from the high energy and nuclear physics community. VERTEX provides an international forum to exchange the experiences and needs of the community, and to review recent, ongoing, and future activities on silicon based vertex detectors. The workshop covers a wide range of topics: existing and future detectors, new developments, radiation hardness, simulation, tracking and vertexing, electronics and triggering, applications to medical and other fields.

The 26th edition of the series will be held on September 10th-15th 2017 at the spa town of "Las Caldas" in Asturias, Spain. Participants are expected to attend the meeting for its full duration, arriving on the venue on September 10th and leaving on September 16th

Participation to the workshop is open to all.
Oral presentations are by invitation only.

Organizing committee accepts abstract only for poster sessions.

A number of grants will be provided for young researchers

Participants
• Abhishek Sharma
• Abraham Antonio Gallas Torreira
• Alessandro Mapelli
• Andrea Alici
• Andrea Garcia Alonso
• Andreas Nürnberg
• Ben Kilminster
• Ben Whitmore
• Carlos Solans Sanchez
• Daniele Passeri
• Edgar Lemos Cid
• Emma Buchanan
• Erik Butz
• Ernesto Migliore
• Esteban Curras Rivera
• Fabian Alexander Forster
• Fabian Huegging
• Fabio Ravera
• Fernando Arteche
• Gagan Mohanty
• Gervasio Gomez
• Giacomo Contin
• Giulio Pellegrini
• Gregor Kramberger
• Heiko Christian Augustin
• Hendrik Jansen
• Ivan Vila Alvarez
• James Michael Keaveney
• Jelena Luetic
• Jiri Kroll
• Jochen Christian Dingfelder
• Jordi Duarte Campderros
• Jory Sonneveld
• Kazuhiko Hara
• Kristian Hahn
• Lorenzo Viliani
• Luis Alejandro Perez Perez
• Marcel Vos
• Marco Petruzzo
• Marcos Fernandez Garcia
• Maria Margherita Obertino
• Marko Mikuz
• Martin Kocian
• Mathieu Benoit
• Mohsine Menouni
• Oscar Augusto De Aguiar Francisco
• Paolo Petagna
• Paul Seyfert
• Prafulla Behera
• Rachel Yohay
• Raphael Tieulent
• Roberto Beccherle
• Ronald Lipton
• Sami Vahanen
• Shaun Roe
• Sofia Otero Ugobono
• Thomas Bergauer
• Tomasz Hemperek
• Veronica Wallangen
• Viktor Veszpremi
• Xavier Llopart Cudie
• Zbynek Drasal
Contact
• Sunday, September 10
• 5:00 PM
Registration
• Welcome cocktail and finger-food dinner
• Monday, September 11
• 1
Welcome
Speaker: Dr Ivan Vila Alvarez (Instituto de Física de Cantabria (CSIC-UC))
• Operational Experience on Current detectors: First block
• 2
Operational experience of ATLAS SCT and Pixel Detector

The ATLAS Inner Detector based on silicon sensors is consisting of a strip detector (SCT) and a pixel detector. It is
the crucial component for vertexing and tracking in the ATLAS experiment.
With the excellent performance of the LHC well beyond the original specification the
silicon tracking detectors are facing substantial challenges in terms of data acquisition, radiation damage to the sensors, and SEUs in the readout ASICs.
The approaches on how the detector systems cope with the demands of high luminosity operation while maintaining excellent performance
through hardware upgrades, software and firmware algorithms, and operational settings, are presented.

Speaker: Martin Kocian (SLAC National Accelerator Laboratory (US))
• 9:25 AM
Questions
• 3
3D Silicon Tracker for AFP - From Qualification to Operation

The ATLAS Forward Proton (AFP) experiment is a detector located ~210 m
away from the ATLAS interaction point on both sides. It's aim is to
tag and measure forward protons produced in diffractive events. The
detector consists of a 3D silicon pixel tracker, to measure the proton
trajectory, as well as a time-of-flight system to suppress
pileup-related backgrounds. Each tracker and the ToF system are placed
inside a Roman Pot, allowing operation in the vicinity of the LHC
beam, up to 2-3 mm. AFP was installed in 2 stages during the LHC
technical shutdowns of 2015-2016 and 2016-2017. This presentation will
give an overview of the silicon sensor qualification as well as the
production, assembly and quality assurance of the tracker modules. The
installation, commissioning and operation of the full detector will
also be discussed.

Speaker: Fabian Alexander Forster (IFAE Barcelona (ES))
• 10:00 AM
Questions
• 4
Operation and Performance of the CMS outer tracker

The CMS outer silicon strip tracker with its more than 15000 silicon modules and 200m2 of active silicon area is in its ninth year of operation at the LHC. We present the performance of the detector in the LHC Run 2 data taking. Results for signal-to-noise, hit efficiency and single hit resolution will be presented. We review the behavior of the system when running at beyond-design instantaneous luminosity and describe challenges observed under these conditions. The evolution of detector parameters under the influence of radiation damage will be presented and compared to simulations.

Speaker: Erik Butz (KIT - Karlsruhe Institute of Technology (DE))
• 10:35 AM
Questions
• 10:45 AM
Coffe Break
• Operational Experience on Current detectors: 2nd block
• 5
Operation of the LHCb silicon tracking and vertexing systems in LHC Run-2

The LHCb detector is a single-arm forward spectrometer with precise silicon-strip detectors in the regions with highest particle occupancies. Around the interaction region, the VErtex LOcator (VELO) has active sensing elements as close as 8 mm from the LHC beams. The Silicon Tracker (ST) consists of a large-area detector located upstream of a dipole magnet, and three stations placed downstream of the magnet. Both detectors share the same front-end electronics, the Beetle chip.

The detectors performed very well throughout LHC Run-1 but new operating conditions for Run-2 pose new challenges. Signal spill-over from adjacent bunch crossings has to be considered in the reconstruction of clusters and tracks.

The non-uniform exposure of the LHCb sensors makes it an ideal laboratory to study radiation damage effects in silicon detectors. The VELO sensors are exposed to fluences of the order of $5\times10^{13}$ 1-MeV neq/cm$^2$ per $fb^{-1}$ while the ST sensor are exposed to more moderate fluences of the order of $10^{12}$ 1 MeV neq/cm$^2$ per $fb^{-1}$.

Several different methods are used to monitor the radiation damage. In
particular, regular High Voltage scans are taken which allow a precise
measurement of the charge collection efficiency (CCE) as function of the voltage.
This analysis is used to determine the operational voltages, and allows to monitor any degradation in the detector performance. In particular the radiation damage affects the cluster finding efficiency due to the double metal layer structure necessary to route the signal out to the FE electronics.

The overall performance of the VELO and ST during Run-2 will be presented.
The results of the latest high voltage scans will be shown, and measurements of the effective depletion voltage will be compared with the expected values that are calculated using the Hamburg model. The impact of these predictions are used to assess the operation of the detector during the remaining Run-2 data taking.

Speaker: Emma Buchanan (University of Bristol (GB))
• 11:40 AM
Questions
• 6
Operational experience with the ALICE ITS

ALICE (A Large Ion Collider Experiment) is the dedicated heavy–ion ex- periment at the CERN LHC designed to address the physics of strongly– interacting matter at extreme energy densities, where the formation of a deconfined phase of matter, the quark–gluon plasma (QGP), is expected. The innermost detector of ALICE is the Inner Tracking System (ITS), a six-layer silicon vertex detector that provides primary vertex reconstruction as well as secondary vertex reconstruction of heavy-flavour and strange par- ticle decays, particle identification and tracking of low-momentum particles and precise determination of the impact parameter.
The ITS cylinder is based on three different technologies and includes from the innermost radius of 3.9 cm to the outermost radius of 43 cm two layers of Silicon Pixel Detector (SPD), two Silicon Drift Detector (SDD) layers and two Silicon Strip Detector (SSD) layers.
In this report, the status and performance of the ALICE ITS detector dur- ing Run2 are summarized and the operational experience and requirements to ensure optimum data quality and data taking efficiency are described.

Speaker: Andrea Alici (Universita e INFN, Bologna (IT))
• 12:15 PM
Questions
• 7
Commissioning and first results from the CMS phase-1 upgrade pixel detector

The phase-I upgrade of the Compact Muon Solenoid (CMS) pixel detector has been designed to maintain the tracking performance at instantaneous luminosities of 2 x 10^34 cm-2 s-1. Both barrel and endcap disk system now feature one extra layer (4 barrel layers and 3 endcap disks), and a digital readout that provides a large enough bandwidth to read out its 124M pixel channels (87.7% more pixels compared to the previous system). The backend control and readout systems have been upgraded accordingly from VME(Versa Module Europa)-based to micro-TCA(Telecommunications Computing Architecture)-based ones. The detector is now also fitted with a bi-phase CO2 cooling system that reduces the material budget in the tracking region. The detector has been installed inside the CMS tracker at the start of 2017 and is now taking data.

In this presentation we discuss experiences in the commissioning and operation of the CMS phase-I pixel detector. We also present the first results from the CMS phase-I pixel detector in this year's LHC proton-proton collision data. The new pixel detector outperforms the previous one in terms of hit resolution, track resolution, and vertex resolution.

Speaker: Jory Sonneveld (Hamburg University (DE))
• 12:50 PM
Questions
• Operational Experience on Current detectors: 3th block
• 8
DAMIC and CONNIE: CCD detectors for low energy threshold dark matter and neutrino searches

CCDs measure ionization energy produced from nuclear or electronic recoils, and can therefore be used as particle detectors with extremely low readout noise. This opens up a new experimental frontier in searching for coherent scattering of dark matter or neutrinos from silicon nuclei that produce ionization energies of only 10s of electron Volts. This talk will explain how CCDs are used for particle identification, and present recent results from two running CCD experiments. DAMIC (Dark Matter in CCDs) is a CCD experiment in SNOLab, optimal for searching for galactic halo WIMP dark matter with mass of around 1 GeV. CONNIE (Coherent Neutrino Nucleus Interaction Experiment) is a CCD experiment searching for the yet-unmeasured coherent scattering of neutrinos from a nuclear reactor at Angra in the Brazilian state of Rio de Janeiro. Issues common to both experiments, such as calibration of nuclear recoils at low energy, will be discussed. Plans for future larger scale experiments will be presented.

Speaker: Ben Kilminster (Universitaet Zuerich (CH))
• 2:55 PM
Questions
• 9
The CT-PPS project: detector hardware and operational experience

The CMS-TOTEM Precision Proton Spectrometer allows extending the LHC physics program by measuring the protons in the very forward regions of CMS. Tracking and timing detectors have been installed along the beam pipe at $\sim 210$ m from the CMS interaction point on both sides of the LHC tunnel. The tracking system consists of a station of silicon strip detectors and a station of silicon pixel detectors on each side. The latter is composed of six planes of 3D silicon pixel sensors bump-bonded to the PSI46dig ROC developed for the CMS Phase I Pixel Tracker upgrade. A track resolution of $\sim 10$ $\mu$m is obtained along the most interesting direction. The future goal is to replace the present strip stations with the pixel ones in order to ensure better performance of multi-track event reconstruction. Each timing station is made of three planes of diamond detectors plus one of Ultra-Fast Silicon Detector (UFSD). A timing resolution of a few tens of picoseconds can be achieved with the present detector; a large R&D effort is ongoing to reach the $10$ ps target resolution. This contribution will describe the hardware characteristics and the present status of the CT-PPS project. The operational experience during the 2017 data taking will also be presented.

Speaker: Fabio Ravera (Universita e INFN Torino (IT))
• 3:30 PM
Questions
• 10
MAPS-based Vertex Detectors: Operational Experience in STAR and Future Applications

The STAR PiXeL detector (HFT PXL) at RHIC is the first application of the thin Monolithic Active Pixel Sensors (MAPS) technology in a collider environment. It is based on 50 μm-thin MAPS sensors with a pitch of 20.7 μm. The sensor is read-out in rolling shutter mode in 185.6 μs. The 170 mW/cm2 power dissipation allows for air cooling and contributes to reducing the global material budget to 0.4% radiation length on the innermost layer. This system took data in Au+Au collisions, p+p and p+Au collisions at √sNN=200 GeV at RHIC, during the period 2014-2016. Operational experience and lessons learned from the construction and the 3 years of data-taking will be presented in this talk. Detector performance and results from 2014 Au+Au data analysis, demonstrating the STAR capabilities of charm reconstruction, will be shown. Following this successful experience, the next-generation MAPS sensor, featuring an integration time shorter than 20 μs, will be used to upgrade the ALICE Inner Tracking System (ITS) at LHC and has been proposed for the vertex detector (MVTX) for sPHENIX, the future nuclear physics experiment for the study of the QGP planned for RHIC. A short outlook on these future applications will conclude the presentation.

Speaker: Giacomo Contin (Lawrence Berkeley National Lab. (US))
• 4:05 PM
Questions
• Poster Exposition and coffee break
• 11
Modeling Radiation Damage Effects in 3D Pixel Digitization for the ATLAS Detector

Modeling Radiation Damage Effects in 3D Pixel Digitization for the ATLAS Detector

Silicon Pixel detectors are at the core of the current and planned upgrade of the ATLAS detector. As the detector in closest proximity to the interaction point, these detectors will be subjected to a significant amount of radiation over their lifetime: prior to the HL-LHC, the innermost layers will receive a fluence in excess of 10^15 neq/cm2 and the HL-LHC detector upgrades must cope with an order of magnitude higher fluence integrated over their lifetimes. This poster presents the details of a new digitization model that includes radiation damage effects to the 3D Pixel sensors for the ATLAS Detector.

Speaker: Veronica Wallangen (Stockholm University (SE))
• 12
50um thin LGAD fabricated for the High Granularity Time Detector of the ATLAS experiment

The objective of the work presented in this talk 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 last experimental results on 50um thin LGAD fabricated for the High Granularity Time Detector of the ATLAS experiment with the geometry of the AltiROC readout chip.

Speaker: Giulio Pellegrini (Centro Nacional de Microelectrónica (IMB-CNM-CSIC) (ES))
• 13
Development of CMS silicon strip detector module mechanics for Phase-II upgrade

The CMS experiment will change it’s silicon tracker completely during phase II upgrade. There is need to develop light and high precision and durable mechanical structure for silicon sensor. The prime purpose of this should also be reducing material in the silicon tracker detector. The group at IIT Madras is heavily involved in R&D of production of this material. We have produced high precision bridge made of AL-CF material and carbon fiber stiffener.

List of contributors: Prafulla Kumar Behera, Sivasrinivasu Devadula, Prabhat Pujahari, peter ngangkham, Md. Alibordi

Speaker: Prof. Prafulla Behera (Indian Institute of Technology Madras (IN))
• 14
Edge-TCT Characterisation on TowerJazz CMOS Sensor Towards the ITK Phase II Upgrade

The ATLAS experiment is planning a major upgrade of its tracking detectors during the Phase-II LHC shut down, to better take advantage of the increased luminosity of the HL-LHC. To this end, new CMOS sensors are being developed. The Edge-Tracient Current Technique (Edge-TCT) measurement method and its latest subsequent preliminary results on the TowerJazz 180nm CMOS technology sensor are presented. The suitability of various pixel sizes is assessed including 50um and 10um-sized structures. Charge sharing is quantified using multi-pixel measurements also at various pixel sizes.

Speaker: Abhishek Sharma (University of Oxford (GB))
• 15
EMC characterization of vertex detectors within the framework of AIDA2020 project

The use of silicon vertex detectors has been used frequently in particle physics and astrophysics detectors. They have been used in astrophysics satellites to detect X-rays, gamma rays and matter/anti-matter as well as in particle physics experiments at CERN or KEK.

During the last years, physics community has been paid attention to the noise issues in this type of detectors. As a result, more detectors designers demand specific facilities in order to perform EMC test. The test results help them to identify sensitive areas of the detector electronics, characterize the coupling mechanism between the noise and sensor and define the noise emissions level compatible with the FEE. Via the AIDA-2020 project, the physics community now has access for the first time to an EMC laboratory specially focused on EMC tests for electronic noise characterization and grounding diagnostics at the Instituto Tecnológico de Aragón (ITAINNOVA) in Spain. The EMC facility has already been used for this purpose during the two first years of the project.

This paper presents a general overview of EMC tests that have been performed on prototypes of vertex detectors at ITINNOVA within AIDA2020 project. The paper shows the type of test that can be performed as well as the analysis and curves that can be obtained to identify the coupling mechanisms between the noise and front end electronics. Today this understanding is critical to define design recommendations and specify the electronics and system topology to increase the FEE robustness to EMI in anticipation of the challenging power distribution schemes proposed for future generation of vertex detectors.

Speaker: Mr Mateo Iglesias (ITAINNOVA)
• 16
LHCb vertex locator upgrade: front-end electronics and firmware.

The LHCb Experiment will be upgraded to a trigger-less system reading out the full detector at 40 MHz event rate with all selection algorithms executed in a CPU farm. The upgraded Vertex Locator (VELO) will be a hybrid pixel detector read out by the "VeloPix" ASIC with on-chip zero-suppression. The upgrade of the LHCb experiment will be installed during the shut-down LS2 of LHC in 2019-2020. It will transform the experiment into a trigger-less system reading out the full detector at 40 MHz event rate. The VELO surrounding the interaction region is used to reconstruct primary and secondary decay vertices and measure the flight distance of long-lived particles. The highest occupancy ASICs will have pixel-hit rates above 900 Mhit/s and produce an output data rate of over 15 Gbit/s, adding up to 1.6 Tbit/s of data for the 41M pixels of the whole VELO.

This poster will present the architecture and design of the VELO on-detector electronics, describing each component and its relation to the LHCb common frame. The main components are: the VeloPix ASIC at 5 mm from the beam in a secondary vacuum tank and exposed to an extremely high inhomogeneous radiation environment, the Opto- and Power Board (OPB) outside of the vacuum, but still in a high radiation environment, the LHCb readout (TELL40) and front-end control (SOL40) boards, placed in a radiation free environment. The whole system is currently being integrated, validated and tested. The results and experience gained from these test will be presented.

Speaker: Edgar Lemos Cid (Universidade de Santiago de Compostela (ES))
• 17
Material budget measurements with beam telescopes

The material budget of a particle physics experiment is a characteristic figure governing its overall performance and detailed knowledge of the material budget of the single components is required for precise modelling of the detector. Beam telescopes, a standard tool in sensor R&D for high-energy physics, allow for the measurement of position-resolved material budgets delivering valuable input to the experiment and the community as a whole.

This contribution covers the basics of multiple Coulomb scattering of charged particles whilst traversing matter, the measurement set-up using a EUDET-type beam telescope, the implementation of a dedicated track model for the precise extraction of the deflections angles, and results from various gauge samples and actual modules. A plug-and-play analysis code is presented, which is open to the community. Additionally, the application of material budget measurements enables a new type of tomography, the track-based multiple scattering tomography, which is discussed in terms of contrast and resolution. This serve as an example for technology transfer from high-energy physics to non-destructive material testing.

Speaker: Hendrik Jansen (Deutsches Elektronen-Synchrotron (DE))
• 18
MuPix8 - a large-area D-MAPS chip

The architecture of the first large area $2\times 1 cm^2$ MuPix8 prototype, produced in an AMS $180 nm$ HV-CMOS process, is presented.
The MuPix8 chip is a High Voltage Monolithic Active Pixel Sensor (HV-MAPS) being developed for the Mu3e experiment which will search for the lepton flavour violating decay $\mu^{+} \rightarrow e^{+}e^{-}e^{+}$ with an unprecedented sensitivity of one in $10^{16}$ decays. To reach this sensitivity goal an ultralight-pixel tracker with $10^{-3}$ radiation lengths per tracking layer and high rate capability is being built. The Mu3e pixel tracker will be based on MuPix chips with a thickness of $50 \mu m$ and a pixel size of $80\times80 \mu m^2$. The hits are readout by on-chip state machines and the data are streamed out via four 1.25 Gbit/s data links.
The Mupix8 is the first prototype which fulfills above requirements and features the full column length of the final chip. In addition, it implements circuitry providing pulse height information, thus allowing for timewalk suppression aiming at time resolution of $10 ns$ or better.

Speaker: Mr Heiko Augustin (Physikalisches Institut Heidelberg)
• 19
The automated assembly of stacked detector modules.

The CMS phase II upgrade outer tracker is built from modules each consisting of two silicon sensors and associated electronics and mechanics. One module type, known as the "PS" module, contains one pixel sensor and one strip sensor that must be assembled to a relative rotational alignment of 800 micro radians. An automated module assembly system is proposed as an alternative to a manual, jig-based, approach. The automated system is based on the integration of a high-precision motion stage with vacuum handling tooling and a vision system. A dedicated software control application obtains images, performs pattern recognition to deduce component positions, and controls the motion stage to arrange components. The current status of the system is discussed with particular emphasis on the pattern recognition techniques and quality of the prototypes produced thus far.

Speaker: James Michael Keaveney (Deutsches Elektronen-Synchrotron (DE))
• 20
The VeloPix ASIC test results

LHCb is a dedicated experiment searching for new physics by studying CP violation and rare decays of b and c quarks. The LHCb silicon vertex detector (VELO) is a crucial component of the experiment. The detector provides precision space points close to the interaction point and thus used to reconstruct b decay vertices, in both the trigger and offline track reconstruction as well as being an important part of the tracking system. In order to match the upgraded LHCb readout system, which aims at a trigger-free read-out of the entire detector at the bunch-crossing rate of 40 MHz, all silicon modules and electronics must be replaced. The upgraded VELO will be a hybrid pixel detector (55x55 um pitch), read out by the VeloPix ASIC derived from the Timepix3. The sensors and ASICs will approach the interaction point to within 5.1 mm and be exposed to a radiation dose of up to 370 Mrad. The hottest ASICs must sustain pixel hit rates of more than 900 Mhits/s and produce an output data rate of over 15 Gbit/s, adding up to 1.6 Tbit/s of data for the whole VELO.

This paper will present an overview of the tests performed on the first version of the VeloPix, issues found and solutions. All digital and analogue functionality has been validated and conforms to specifications. Low temperature operation was verified and tests with a probecard were successful. Total Ionising Dose irradiations have been carried out with irradiation up to 400 Mrad which resulted in no change in digital power consumption and no drift in analogue parameters. Two testbeams have been carried out. One to crosscheck the synchronization, high rate capabilities and tracking performance using 5 VeloPix planes in a telescope at rates up to 300 Mtracks/s. Another one for timewalk studies using the Timepix3 telescope. Jitter on the clock that is used for the 4.8 Gbits/s serialiser generates erroneous packets, which can be reduced by adding decoupling outside of the chip and tuning the internal clock phase. Four sessions of Single Event Effects testing have been carried out in the Heavy ion facility in Louvain-la-Neuve. We found unexpected Single Event Latch-up (SEL), large cross section for the reset circuit and some small design flaws. To solve/mitigate SEE and jitter issues a second version of the VeloPix will be submitted. This poster will describe the architecture of the VeloPix chip, the test results and design changes that have been implemented.

Speaker: Edgar Lemos Cid (Universidade de Santiago de Compostela (ES))
• 21
Vertex Reconstruction and Performance in ATLAS

Efficient and precise reconstruction of the primary vertices in LHC collisions is essential in both the reconstruction of the full kinematic properties of a hard-scatter event and of soft interactions as a measure of the amount of pile-up. The reconstruction of the primary vertices in the busy, high pile up environment of the LHC is a challenging task. The challenges and novel methods developed by the ATLAS experiment to reconstruct vertices in such environments will be presented. The performance of the current vertexing algorithms using Run-2 data will be presented and compared to results from simulation. Additionally, data-driven methods to evaluate vertex resolution, and details of upgrades to the ATLAS inner detector will be presented.

Speaker: Mr Ben Whitmore (Lancaster University)
• Detectors in design and construction: first block
• 22

The Vertex Locator (VELO) surrounding the interaction region is used to reconstruct the collision points (primary vertices) and decay vertices of long-lived particles (secondary vertices). The VELO detector will be changed for the upgrade of the LHCb detector to be able to run at 5 times higher instantaneous luminosity. The modules will each be equipped with 4 silicon hybrid pixel tiles, each read out with by 3 VeloPix ASICs. The highest occupancy ASICs will have pixel hit rates of 900 Mhit/s and produce an output data rate of over 15 Gbit/s, with a total rate of 1.6 Tbit/s anticipated for the whole detector. The VELO modules are located in vacuum, separated from the beam vacuum by a thin custom made foil. The foil will be manufactured through a novel milling process and possibly thinned further by chemical etching. The front-end hybrid hosts the VeloPix ASICs and a GBTx ASIC for control and communication. They hybrid is linked to the the the opto-and-power board (OPB) by 60 cm electrical data tapes running at 5 Gb/s. The tapes must be vacuum compatible and radiation hard and are required to have enough flexibility to allow the VELO to retract during LHC beam injection. The OPB is situated immediately outside the VELO vacuum tank and performs the opto-electrical conversion of control signals going to the front-end and of serial data going off-detector. The board is designed around the Versatile Link components developed for high-luminosity LHC applications. From the OPB the detector data are sent through 300 m of optical fibre to LHCb's common readout board (PCIe40). The PCIe40 is an Altera Arria10-based PCI-express control and readout card capable of 100 Gb/s data throughput. The PCIe40 firmware is designed as a series of common components with the option for user-specific data processing. The common components deal with accepting the input data from the detector over the GBT protocol, error-checking, dealing with reset signals, and preparing the data for the computing farm. The VELO-specific code would, for example, perform clustering of hits and time reordering of the events scrambled during the readout.

An additional challenge is the non uniform nature of the radiation damage, which results in requiring a guard ring design with excellent high voltage control. The performance of the prototype sensors has been investigated in a test beam, exploring tests of irradiated samples. A collection of preliminary results will be presented.

The design of the complete VELO upgrade system will be presented with the latest results from the R\&D. The VELO upgrade will utilise the latest detector technologies to read out at this rate using while maintaining the necessary radiation hard profile and minimising the detector material.

Speaker: Edgar Lemos Cid (Universidade de Santiago de Compostela (ES))
• 5:20 PM
Questions
• 23
The CMS Pixel Detector Upgrade and R&D developments for the High Luminosity LHC

The High Luminosity Large Hadron Collider (HL-LHC) at CERN is expected to collide protons at a centre-of-mass energy of 14 TeV and to reach the unprecedented peak instantaneous luminosity of $5\cdot10^{34}\,{\rm cm^{-2} s^{-1}}$ with an average number of pileup events of 140. This will allow the ATLAS and CMS experiments to collect integrated luminosities up to $3000\,{\rm fb^{-1}}$ during the project lifetime. To cope with this extreme scenario the CMS detector will be substantially upgraded before starting the HL-LHC, a plan known as CMS Phase-2 upgrade. The entire CMS silicon pixel detector will be replaced and the new detector will feature increased radiation hardness, higher granularity and capability to handle higher data rate and longer trigger latency. In this talk the Phase-2 upgrade of the CMS silicon pixel detector will be reviewed, focusing on the features of the detector layout and on developments of new pixel devices.

Speaker: Lorenzo Viliani (Universita e INFN, Firenze (IT))
• 5:55 PM
Questions
• 24
The Muon Forward Tracker, upgrade of the ALICE experiment

ALICE is the experiment specifically designed for the study of the Quark-Gluon Plasma in heavy-ion collisions at the CERN-LHC. The ALICE detector will be upgraded during the LHC Long Shutdown 2, planned for 2019-2020, in order to fully exploit the large integrated luminosity that will be provided by the LHC in Run 3 and Run 4.

The Muon Forward Tracker (MFT), an internal tracker added in the acceptance of the existing Muon Spectrometer and designed to cover the pseudorapidity range 2.5 < eta < 3.6, is part of the ALICE detector upgrade programme, allowing for a crucial improvement of the measurements presently done with the Muon Spectrometer, and giving access to new measurements. The precise measurement of the offset to the primary vertex for the muon tracks, in particular,
will permit for the first time in ALICE the statistical separation of open charm ($c\tau \sim 120-300~\mu$m) and beauty ($c\tau \sim 500~\mu$m) production at forward rapidity, rejecting at the same time a large fraction of background muons coming from pion and kaon decays.

The setup of the MFT is an assembly of circular planes made of CMOS Monolithic Active Pixel Sensors (MAPS), to be installed between the interaction point and the hadron absorber of the Muon Spectrometer. The total material budget of the MFT tracking planes, the radiation hardness of their components, coupled with the high granularity of the pixel sensors and the envisaged readout speed, fulfill the conditions for the operation at the luminosities foreseen for the LHC Run~3 heavy-ion program. The ambitious programme of high-precision measurements expected to characterize the ALICE muon physics after 2020, will also impose the upgrade of the front-end and readout electronics of the existing Muon Spectrometer.
A selection of results from the physics performance studies will be presented, together with an overview of the technical aspects of the MFT upgrade project.

Speaker: Dr Raphael Tieulent (IPN-Lyon, CNRS/IN2P3, Université de Lyon)
• 6:30 PM
Questions
• 25
Upgrade of ATLAS ITk Pixel Detector

The high luminosity upgrade of the LHC (HL-LHC) in 2026 will provide new challenges to the ATLAS tracker. The current inner detector will be replaced with an entirely-silicon inner tracker (ITk) which will consist of a five barrel layer Pixel detector surrounded by a four barrel layer Strip detector. The expected high radiation levels are requiring the development of upgraded silicon sensors as well as new a front-end chip. The dense tracking environment will require finer granularity detectors and low mass global and local support structures. The data rates will require new technologies for high bandwidth data transmission and handling. The current status of the ITk ATLAS Pixel detector developments as well as different layout options will be reviewed.

Speaker: Fabian Huegging (University of Bonn)
• 7:05 PM
Questions
• Tuesday, September 12
• Detectors in design and construction: 2nd Block
• 26
Design and construction of the LHCb Upstream Tracker
Speaker: Marco Petruzzo (Università degli Studi e INFN Milano (IT))
• 9:25 AM
Questions
• 27
ATLAS ITk Strip Detector for High-Luminosity LHC

The ATLAS experiment is currently preparing for an upgrade of the tracking system in the course of the High-Luminosity LHC that is scheduled for 2026. The expected peak instantaneous luminosity up to 7.5E34 per second and cm2 corresponding to approximately 200 inelastic proton-proton interactions per beam crossing, radiation damage at an integrated luminosity of 3000/fb and hadron fluencies over 1E16 1 MeV neutron equivalent per cm2, as well as fast hardware tracking capability that will bring Level-0 trigger rate of a few MHz down to a Level-1 trigger rate below 1 MHz require a replacement of existing Inner Detector by an all-silicon Inner Tracker (ITk) with a pixel detector surrounded by a strip detector. The current prototyping phase, that is working with ITk Strip Detector consisting of a four-layer barrel and a forward region composed of six discs on each side of the barrel, has resulted in the ATLAS ITk Strip Detector Technical Design Report (TDR), which starts the pre-production readiness phase at the involved institutes. In this contribution we present the design of the ITk Strip Detector and current status of R&D of various detector components.

Speaker: Jiri Kroll (Acad. of Sciences of the Czech Rep. (CZ))
• 10:00 AM
Questions
• 28
The CMS Outer Tracker Upgrade for the High Luminosity LHC

The era of High Luminosity LHC will pose unprecedented challenges for detector design and operation. The planned luminosity of the upgraded machine is 5*10^34cm^-2s^-1, possibly reaching an integrated luminosity of 3000fb-1 by the end of 2037. CMS Tracker detector will have to be replaced in order to fully exploit the delivered luminosity and cope with the demanding operating conditions. The new detector will provide robust tracking as well as input for the first level trigger. The focus of this talk is the replacement of the CMS outer tracker system, describing new layout and technological choices together with some highlights of R&D activities.

Speaker: Jelena Luetic (Universite Libre de Bruxelles (BE))
• 10:35 AM
Questions
• 10:45 AM
coffee break
• Detectors in design and construction: 3th block
• 29
The Belle-II Pixel Detector

The construction of the new e+e- super flavor factory SuperKEKB in Tsukuba, Japan has been finalized
and the machine is designed to deliver an instantaneous luminosity 40 times higher than its predecessor KEKB.
For high-performance vertex reconstruction, the Belle II experiment will be equipped with a highly granular,
ultra-transparent active pixel detector (PXD) very close to the interaction point. This new pixel detector
consists of two layers of active pixel sensors based on the DEPFET technology, which combines
charged-particle detection with in-pixel amplification by integration of a field effect transistor
in a fully depleted silicon bulk for each pixel. A complete detector system including solutions for the ultra-thin sensors,
their mechanical support and cooling, the front-end electronics, services and a DAQ system able to handle the expected large data rate from the PXD is being constructed. Recent milestones are a full system test of the vertex detector in a test beam
and the commissioning of the BEAST II pre-experiment which is planned to start in early 2018.
In this presentation, an overview of the Belle II PXD system, its construction status, detailed module characterizations
and final system tests will be given.

Speaker: Jochen Christian Dingfelder (University of Bonn (DE))
• 11:40 AM
Questions
• 30
Belle II Silicon Vertex Detector

The Belle II experiment at the SuperKEKB collider is the next-generation flavor factory, which will operate at an unprecedented instantaneous luminosity of 8×1035 cm-2s-1, about 40 times larger than its predecessor Belle experiment. Its vertex detector is composed of a two-layer DEPFET based pixel detector (PXD) and four-layer double-sided silicon microstrip detector (SVD). To achieve a precise vertex reconstruction and excellent low-momentum tracking, even under the harsh background and high trigger rate of 30 kHz, the SVD employs several innovative techniques. To minimise the capacitive noise, 1,748 APV25 ASIC chips that read out signals from 224k strips, are directly mounted on the modules relying on the novel Origami concept. The analog signals from APV25 after digitised by an FADC system are sent to the central DAQ and also to online tracking system based on SVD hits to provide the region of interests to PXD, enabling reduction of the latter data size to achieve the required bandwidth and data storage space. In this talk, we highlight design principles and construction status of the Belle II SVD, before closing with the path towards its integration and commissioning.

Speaker: Gagan Mohanty (Tata Inst. of Fundamental Research (IN))
• 12:15 PM
Questions
• 31
Mu3e vertex and tracking system

The Mu3e experiment is searching for the lepton flavour violating decay μ+→e+e−e+. In an environment of up to 10^9 muon decays per second the detector needs to provide precise vertex, time and momentum information to suppress both physics and accidental background. The detector consists of cylindrical layers of 50 μm thin High Voltage Monolithic Active Pixel Sensors (HV-MAPS) placed in a 1 T magnetic field, which allow a precise vertex and momentum reconstruction. Additional layers of fast scintillating fibre and tile detectors are providing sub-nanosecond time resolution.

The development of the Mu3e vertex and tracking system are described, showing the R&D progress on the chip technology and module construction.

Speaker: Heiko Christian Augustin (Ruprecht-Karls-Universitaet Heidelberg (DE))
• 12:50 PM
Questions
• New developments
• 32
Overview and perspectives of depleted CMOS sensors

To cope with increased radiation levels expected at the HL-LHC new approaches are being investigated using monolithic CMOS pixel detectors where readout electronics and depleted charge collection layer are combined. Those devices rely on radiation hard process technology, multiple nested wells, and high resistivity substrates to achieve significant depletion depths. They can be thinned and backside processed for biasing.
Since 2014, members of more than 20 groups in ATLAS are colaborating in CMOS pixel R&D in an ATLAS Demonstrator program pursuing sensor design and characterisations with the goal to demonstrate that depleted CMOS pixels are suited for high rate, fast timing and high radiation operation at LHC. Many CMOS technology vendors have been approached in this effort.
This presentation introduces challenges for the usage of CMOS pixel detectors at HL-LHC and gives a summary of different concepts and the current state of designs of depleted CMOS prototypes.

Speaker: Tomasz Hemperek (University of Bonn (DE))
• 2:55 PM
Questions
• 33
Silicon Sensor technologies for timing (LGAD)

The working conditions at future accelerators will require the capability of taking data at unprecedented intensities and the possibility to distinguish events separated by a few tens of picoseconds will become of utmost importance. To face this challenge, intense R&D programs in silicon sensors are currently being carried on, with the ultimate goal of reaching concurrent excellent position and time resolutions. In this contribution I will review the status and the expectations on the production of fast silicon devices and I will point out the interplay of parameters such as internal gain, pixel volume and segmentation, electronic and shot noise in the design of the optimum sensor. Challenges related to the sensor manufacturing and the detector signal processing will be discussed, and first results from recently produced prototypes will be shown and compared to simulation.

Speaker: Maria Margherita Obertino (Universita e INFN Torino (IT))
• 3:30 PM
Questions
• 34
Recent Developments of SOI Pixel Devices

We are developing monolithic pixel devices utilizing Lapis 0.20um FD-SOI CMOS process. A couple of issues needed to solve in adopting SOI technology to pixel sensors for high-energy experiments, namely, back-gate effects, noise pick-up and total ionization dose (TID) damage, have been successfully overcome ultimately by use of double-SOI wafers. The application of SOI technology has been boosted recently through five-year fund of Grant-in-Aid for Scientific on Innovative Area Research. Major achievements in this development activities will be covered, including FPIX test beam results, achieving a spatial resolution as small as 0.7um, and and SOFIST development of the ILC. The FPIX has shown TID tolerance up to 1 MGy of irradiation.

Speaker: Kazuhiko Hara (University of Tsukuba (JP))
• 4:05 PM
Quesitons
• Poster Exposition and coffee break
• Electronics and System Integration
• 35

Effective thermal management of modern silicon detectors for HEP experiments is a challenging task. Although technological progresses on electronic chips allow for remarkable lowering of their specific power consumption at every new generation, the increasing request for performance and the very large number of sensing modules, concentrated in a confined volume in convoluted geometries, determine a detector power dissipation per unit volume comparable to the one of the most demanding high power electronics applications. This, added to a hostile radiation environment and to the well-known requirements of material budget minimization (very specific to our field), pushes the thermal design towards the adoption of advanced technologies.
This is in particular true for pixel detectors, where only a careful weighting of all the design requirements may lead to the optimal choice of the cooling technology, both at system level and for local thermal management solutions. There is unfortunately no universal “magical recipe”, providing the designers with the best-adapted thermal management solution for every pixel detector. A lot is indeed left to the appreciation of the correct balance between requirements that are often conflicting. Some of these requirements can be easily translated into well-defined numerical values, like the minimal radiation length for the target physics performance, or the power density to be evacuated from the detector volume. Other ones however, like design and manufacturing complexity, reliability, damage tolerance, or maintainability are much less adapted to an objective quantification.
The talk will review some of the most recent trends in vertex detector cooling, with a special focus placed onto the numerous upgrade programmes ongoing in the HEP community. The most impacting advantages and disadvantages of the different classes of solutions adopted or under study will be discussed, with the intention to provide a critical view of the options available.

Speaker: Paolo Petagna (CERN)
• 5:25 PM
Questions
• 36
The NA62 GTK, from silicon microchannel cooling plates to tracking detectors

Since the beginning of the NA62 experiment, 9 silicon microchannel cooling plates have been integrated into GigaTracKer (GTK) modules. In 2014, the first module was installed in the NA62 beam line, pioneering the use of microfluidic devices for the thermal management of detectors in HEP experiments. In 2016, three fully functional GTK modules were installed in the and they were successfully operated without noise for the physics run.

The GTK is an essential element in the K+⟶𝜋+𝝂𝝂- measurement. It determines the momentum and the direction of the kaon entering the NA62 experiment with a time resolution of 100 ps, better than the 200 ps expected from the design. About 5 x 1011 K+ decays have been taken by the NA62 experiment to study the K+⟶𝜋+𝝂𝝂- decay.

The poster will highlight the microfabrication process of the silicon cooling plates, the construction of the modules as well as their installation and operation in the beam line.

Speaker: Alessandro Mapelli (CERN)
• 6:00 PM
Questions
• 37
Microchannel Cooling techniques at LHCb
Speaker: Oscar Augusto De Aguiar Francisco (CERN)
• 6:35 PM
Questions
• Wednesday, September 13
• Electronics and System Integration: First block
• 38
RD53A: a Large Scale prototype of a New generation Pixel Readout ASIC for the HL_LHC experiment

The R&D program for a 65nm CMOS pixel chip of new generation for extremely high rate (3GHz/cm2) and very high radiation levels (1Grad) for ATLAS and CMS phase 2 pixel upgrades has taken place within the RD53 collaboration. Radiation test structures have been realized and characterized; building blocks and analog very front ends have been produced and tested. Small scale demonstrators with 64x64 array of 50x50 um2 pixels containing complex digital architectures have been produced and showed the feasibility of operating at very small noise and in-time thresholds.

Based on the past experience and achievements, the collaboration has designed in the last year a large scale prototype (20mm x 12 mm) called RD53A, that will be submitted for production during summer 2017. It contains a large number of different building blocks (analog front-ends, calibration circuit, Bandgap, DACs, ADC, PLL, serializer, cable driver, serial IO, serial power Shunt-LDO regulator, on-chip monitoring of temperature/radiation/current/voltages, etc.) that have been prototyped and extensively tested, including irradiation, before being finalized and integrated on the RD53A demonstrator.

The main concepts of RD53A are described, explaining how it defines the baseline for the development of the pixel chips for the ATLAS and CMS experiments for HL_LHC

Speaker: Roberto Beccherle (INFN, Pisa (IT))
• 9:55 AM
questions
• 39
Solutions for flip chip bonding of future pixel detectors

Flip chip processing of pixel detectors face many technological challenges when moving to finer CMOS technology nodes, production of 300 mm wafers and having larger chips than ever. In addition, finer pixel pitches and thinner CMOS chips are required, which will cause headache for the wafer bumping and assembly foundries. There will be fewer foundries, which are able provide all the required services, and thus the responsibilities will have to be shared within several foundries. Despite having more challenging logistic scheme and taking the technological challenges to next level, the hybrid pixel modules should be cheaper than ever in order to have large areas covered within the pixel detectors.

This presentation considers various technological aspects of flip chip process for the hybrid pixel detector and suggestions for remedies are given to overcome the problems in flip chip process of hybrid pixel detectors for vertex/tracking applications. Wafer bumping concepts and solder bump structures will be introduced for fine pixel pitches and low soldering temperatures. Thin CMOS chip flip chip bonding solutions, novel Si sensors and future large-area tiling of Si sensor modules using through silicon vias will be introduced.

• 10:30 AM
Questions
• 40
3D IC integration
Speaker: Ronald Lipton (Fermi National Accelerator Lab. (US))
• 11:05 AM
questions
• 11:15 AM
Coffe Break
• Electronics and System Integration: 2nd block
• 41
The Timepix family ASICs

The Timepix chip is composed of a matrix of 256 x 256 square pixels at a pitch of 55um It can be programmed on a pixel-by-pixel basis to record particle arrival time, Time-over Threshold (ToT) or particle counts. This has made it a very versatile device and it has been used in the readout of various segmented semiconductor detectors, micro channel plates and different kinds of gas gain grid (GEM, InGrid etc). The chip has been used in a large variety of applications including classroom experiments, space science, space dosimetry, X-ray diffraction and spectroscopy, neutron imaging and finally back to High Energy Physics. This paper will attempt to summarize the Timepix family of chips and its applications.

Speaker: Xavi Llopart Cudie (CERN)
• 12:10 PM
Questions
• 42
Poster Summary
Speaker: Abraham Antonio Gallas Torreira (Universidade de Santiago de Compostela (ES))
• 4:00 PM
Group photo
• 4:30 PM
Social Activity (Tour to the Asturian pre-romanesque monuments)

16:30 H. Pick up at Hotel de las Caldas

    Visit to San Julián los Prados, asturian pre-romanesque church from the 9th Century, UNESCO World Heritage Site.

Panoramic Tour of the city by bus

Visit to Santa María del Naranco and San Miguel de Lillo, Palace and Church from the 9th Century and also UNESCO World Heritage Sites.

Guided walking tour in the Old Quarter in Oviedo. Pedestrian. We will discover the main squares, churches and palaces and also the history of the City.


20:30 H. End of visit at Hotel de las Caldas.

• Thursday, September 14
• 4th dimensional tracking and vertexing (timing): First block
• 43
4th dimensional tracking: the GigaTracker of NA62 experiment.

The GigaTracker is a lightweight hybrid silicon pixel detector built for the NA62 experiment at CERN,
which aims at measuring the branching fraction of the ultra-rare kaon decay $K^+\rightarrow \pi^+\nu\bar{\nu}$ at the CERN SPS.
The detector consists of three stations, 61$\times$27 mm$^2$ each, which tracks particles in a 75 GeV/$c$ hadron beam with a flux reaching
1.3 MHz/mm$^2$ and provides single-hit timing with 130 ps resolution.
Each station is composed of a 200 $\mu$m thick planar silicon sensor,
segmented in 300$\times$300 $\mu$m$^2$ pixels, bump-bonded to 2$\times$5 custom 100 $\mu$m thick ASIC, called TDCpix.
Each TDCpix contains 40$\times$45 asynchronous pixels, and is instrumented with 720 time-to-digital converter channels with 100 ps bin.
The three stations are installed in vacuum (about 10$^{-6}$ mbar) and cooled with liquid $\mathrm{C_6F_{14}}$ circulating through micro-channels etched inside few hundred of micrometers thick silicon plates.
The total material budget is less than 0.5% $X_0$ per station.
Detector description, operational experience and performance from the NA62 experimental run in 2016, at about 30% the nominal beam intensity, will be presented.

Speaker: Ernesto Migliore (Universita e INFN Torino (IT))
• 9:25 AM
Questions
• 44
Precision timing for the High Luminosity Upgrade of CMS

The projected proton beam intensity of the High Luminosity Large Hadron Collider (HL-LHC), slated to begin operation in 2026, will result in between 140 and 200 concurrent proton-proton interactions per 25 ns bunch crossing. The scientific program of the HL-LHC, which includes precision Higgs coupling measurements, measurements of vector boson scattering, and searches for new heavy or exotic particles, will benefit greatly from the enormous HL-LHC dataset. However, particle reconstruction and correct assignment to primary interaction vertices presents a formidable challenge to the LHC detectors that must be overcome in order to reap that benefit. Time tagging of minimum ionizing particles (MIPs) produced in LHC collisions with a resolution of 30 ps provides further discrimination of interaction vertices in the same 25 ns bunch crossing beyond spatial tracking algorithms. The Compact Muon Solenoid (CMS) Collaboration is pursuing two technologies to provide MIP time tagging for the HL-LHC detector upgrade: LYSO:Ce crystals read out by silicon photomultipliers (SiPMs) for low radiation areas and silicon low gain avalanche detectors (LGADs) for high radiation areas. This talk will motivate the need for a dedicated timing layer in the CMS upgrade, describe the two technologies and their performance, and present simulations showing the improvements in reconstructed observables afforded by four dimensional tracking.

Speaker: Rachel Yohay (Florida State University (US))
• 10:00 AM
Questions
• 45
High Granularity Timing Detector at Atlas
Speaker: Gregor Kramberger (Jozef Stefan Institute (SI))
• 10:35 AM
Questions
• 10:45 AM
Coffee break
• 46
Review of RD42 activities
Speakers: Harris Kagan (Ohio State University), Marko Mikuz (Jozef Stefan Institute (SI))
• 11:40 AM
Questions
• 47
Review of RD50 activities
Speaker: Marcos Fernandez Garcia (Universidad de Cantabria (ES))
• 12:15 PM
Questions
• 48
Main Results of Radiation Characterization of CMOS 65nm technology and the impact on the design of RD53A, a large scale pixel chip prototype for HL_LHC.

The results of several years of radiation characterization of the CMOS 65nm technology at both transistor level and circuit level will be summarized here.The degradation of the performance of 65 nm MOSFETs upon radiation exposure was studied using 10-keV X-rays, but also using 3-MeV protons. Models that parameterize the effect of total dose on MOS performance have been defined according to the measurements made, in particular for 200 and 500 Mrad.
The analog circuitry and building blocks designed in the framework of RD53 collaboration have been made radiation hard by design following few prescriptions and using the irradiation models. A chip has been designed to study the effect of TID on several different types of standard cell libraries provided by the foundry (Digital-RAD, DRAD chip). In particular ring oscillators have been designed in different flavors, so to measure how much the digital transitions are slowed down by irradiation.
The design of the RD53A, a large scale prototype of a new generation pixel ASIC, takes into account the radiation characterization of the CMOS 65nm technology and it is meant to demonstrate the capability to make pixel chips that can sustain and survive the extremely challenging operating conditions determined by HL_LHC in the inner layers of the experiments.

Speaker: Mohsine Menouni (Centre National de la Recherche Scientifique (FR))
• 12:50 PM
Questions
• 49
Speaker: Marko Mikuz (Jozef Stefan Institute (SI))
• 2:55 PM
Questions
• 50

In view of the LHC luminosity upgrade (HL-LHC), new radiation tolerant silicon sensors are being developed. Such sensors will have to cope with radiation levels of up to about $10^{16}\text{ fast hadrons}/\text{cm}^2$. Under these conditions, the degradation of the charge collection efficiency remains the main obstacle in detector operation. Furthermore, as new functionalities are given to silicon sensors, such as fast timing, new developments in sensor technologies and particularly in radiation tolerance are required. One of the options in order to tackle these challenges is the use of radiation tolerant silicon sensors with intrinsic charge gain, aiming to improve signal amplitudes after high radiation levels and improve the timing capabilities of silicon sensors. One of the proposed technologies for intrinsic gain sensors is Low Gain Avalanche Detectors (LGADs).

This work focuses on the study of a set of LGADs produced by CNM, Barcelona (Run 7859). Several samples were irradiated with 24-GeV protons up to different fluences, ranging between $10^{12}$ and $10^{15}\text{ 1 MeV n}_\text{eq}/\text{cm}^2$. The measurements performed to characterise the devices include TCT, edge-TCT, TPA-TCT, and CV/IV measurements. The main goal of these studies was to analyse the voltage required to fully deplete the multiplication layer of LGADs, and measure the gain degradation as well as the distribution of the electric field inside the devices as a function of radiation fluence. In order to do so, the measurements were performed under different temperature, read-out and biasing conditions.

The obtained data confirm that for the investigated highly irradiated LGADs the depletion starts from the back electrode, thus shifting the onset of the charge multiplication towards high voltages.

Speaker: Sofia Otero Ugobono (CERN/Universidade de Santiago de Compostela (ES))
• 3:30 PM
Questions
• 51
Speaker: Daniele Passeri (University & INFN, Perugia (IT))
• 4:05 PM
Questions
• 4:15 PM
Coffe Break
• Future Collider Experiments
• 52
Status & Challenges of Tracker Design for FCC-hh

A 100TeV proton collider is a central aspect of the Future Circular Collider (FCC) study. An integral part of such a study is the conceptual design of individual detector systems that can exploit the luminosities reaching values up-to $30\times10^{34} \mathrm{cm}^{-2} \mathrm{s}^{-1}$. One of the key limitations in detector design arises from an increased number of pile-up events O(1000), which makes the tracking and identification of vertices extremely challenging. This talk will review the general ideas, which drive the current tracker/vertex detector design for the FCC-hh, like material budget, granularity in R-Ф & Z, pattern recognition & tagging capabilities, uniformity of magnetic field across large detection region, occupancy and data rates. We will also discuss the limits of current tracker/vertex detector technologies and requirements on their progress to meet the challenging conditions of FCC-hh environment.

Speaker: Zbynek Drasal (CERN)
• 5:10 PM
Questions
• 53
Silicon pixel R&D for CLIC

The physics aims at the proposed future CLIC high-energy linear e+e- collider pose challenging demands on the performance of the vertex and tracking detector system. In particular the 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 requirements include ultra-low mass, facilitated by power pulsing and air cooling in the vertex-detector region, small cell sizes and precision hit timing at the few-ns level. 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. We present the proposed detector system, and give an overview of the ongoing technology R&D, including results from recent beam tests of fine-pitch silicon pixel detector prototypes.

Speaker: Andreas Nürnberg (CERN)
• 5:45 PM
Questions
• 54
Vertex and Trakcing for LC detectors
Speaker: Luis Alejandro Perez Perez (Institut Pluridisciplinaire Hubert Curien (FR))
• 6:20 PM
Questions
• Friday, September 15
• Offline Tracking and vertexing
• 55
Performance of the ATLAS tracking
Speaker: Shaun Roe (CERN)
• 9:25 AM
Questions
• 56
Tracking Performance and alignment of the recently upgraded CMS tracker

The CMS Tracker consists of two tracking systems utilizing semiconductor technology: the inner pixel and the outer strip detectors. The tracker detectors occupy the volume around the beam interaction region, between 3 cm and 110 cm in radius and up to 280 cm along the beam axis. The pixel detector consists of 124 million pixels in about 2 m2 total area. It plays a vital role in the seeding of track reconstruction algorithms, and in the reconstruction of primary interactions and secondary decay vertices. It is surrounded by the strip tracker with 10 million read-out channels in 200 m2 total area used in track building. The Tracker is operated in a high-occupancy and high-radiation environment represented by particle collisions in the LHC. The performance of the silicon strip detector continues to be of high quality. The pixel detector that has been used in Run 1 and in the first half of Run 2 was replaced with a new one (the so called Phase 1 Upgrade Pixel Detector) well suited to match the instantaneous luminosity the LHC would reach 2x10E34cm−2s−1. The Phase 1 upgrade of the CMS pixel detector was built to operate at such a high rate with a new digital readout chip. The detector's new layout has an additional inner layer with respect to the previous one; it allows for more efficient tracking with smaller fake rate at higher event pile-up. The presentation will focus on the first results obtained during the commissioning of the new detector. Results will include challenges we had to face during the first data taking to reach the optimal tracking efficiency. Details will be given on the performance at high occupancy with respect to local observables, such as the the read-out thresholds, hit reconstruction efficiency and resolution. The alignment strategy for the reconstruction of the first cosmic ray and collision data will be outlined. The performance of track reconstruction algorithms will be shown.

Speaker: Viktor Veszpremi (Wigner RCP, Budapest (HU))
• 10:00 AM
Questions
• 10:10 AM
Coffee break
• Online Tracking and vertexing
• 57
Level-1 track finding for the CMS HL-LHC upgrade
Speaker: Kristian Hahn (Northwestern University (US))
• 11:05 AM
Questions
• 58
Real-time alignment and reconstruction in Run 2 and its performance at the LHCb experiment
Speaker: Adam Davis (Tsinghua University (CN))
• 11:40 AM
Questions
• 59
Tracking, Vertexing and data handling strategy for the LHCb upgrade

For Run III (2021 onwards) of the LHC, LHCb will take data at an instantaneous luminosity of 2 × 10^{33} cm−2 s−1, five times higher than in Run II (2015-2018). To cope with the harsher data taking conditions, the LHCb collaboration will upgrade the DAQ system and install a purely software based trigger, in addition to various detector upgrades. The high readout rate contributes to the challenge of reconstructing and selecting events in real time.

Special emphasize in this talk will be put on the need for fast track reconstruction in the software trigger. I demonstrate how the modified detector infrastructure will be able to face this challenge and discuss the necessary changes to the reconstruction sequence. I present a novel strategy to distribute and maximise the bandwidth among the different physics channels using a genetic algorithm.

The data processing chain includes a re-design of the event scheduling, introduction of concurrent processing, optimisations in processor cache accesses and code vectorisation. Furthermore changes in the areas of event model, conditions data and detector description are foreseen.

Speaker: Paul Seyfert (CERN)
• 12:15 PM
Questions
• 60
Workshop Summary
Speaker: Thomas Bergauer (Austrian Academy of Sciences (AT))