Welcome of the participants; general information regarding this Workshop
HRTEM, LA-ICP-MS and DLTS techniques were employed to characterize several types of B-doped silicon diodes after irradiation with hadrons. The HRTEM results on LGAD samples irradiated with 1019cm-2 show that there is a preferential grouping of defects along tracks normal to the film surface. We will present the LA-ICP-MS technique, recently installed in NIMP, with which we could estimate the...
In this work the Thermally Stimulated Current (TSC) technique has been used to investigate the properties of the radiation induced BiOi defect complex by 23 GeV protons, including activation energy, capture cross section, defect concentration as well as the annealing behavior. At first isothermal annealing (at 80 °C for 0 to 180 minutes) followed by isochronal annealing (for 15 minutes between...
The measurement of spectral dependence of photoconductivity permits to investigate the deep level spectrum, recombination at the surface and photoelectric quantum yield.
This presentation deals with observation of an increase of quantum yield at lover photon energy in highly irradiated Si in comparison with less or non-irradiated Si. The effect was observed in neutron irradiated Si to the...
The time stability of a single crystal diamond radiation detector in response to alpha particle irradiation is studied in this work. A diamond detector is fabricated from a free-standing single crystal diamond plate and is packaged for the alpha irradiation studies. The detector under the bias voltage of +70 V is kept under constant alpha irradiation from a mixed α-source having major activity...
Owing to their low dark current, high transparency, high thermal conductivity and potential radiation hardness, there is a special interest in silicon carbide devices for radiation monitoring in radiation harsh environments or operation at elevated temperatures.
In this work, segmented four-quadrant pn junction diodes produced on epitaxied 4H-SiC substrates are studied. The impact of 2-MeV...
Generation of the current by radiation-induced defects in Si p-n junction detectors is one of the processes responsible for their radiation degradation. In the study, analysis of the I-V characteristics is performed for the profiling of radiation defects acting as current generation centers. The experimental results are obtained for the Si p+-n-n+ diodes with a nonuniform defect distribution...
Radiation defects induced by the harsh radiation environment in the CMS experiment heavily impact the operation of the upgraded silicon pixel detector, that has been installed in the beginning of 2017. During the data taking period of 2017-2018, the phase 1 CMS pixel detector, composed of 4 barrel layers and 3 endcap disks, has experienced up to $1 \times 10^{15} n_{eq}/cm^{2}$. In this...
Non-ionizing energy loss causes bulk damage to the silicon sensors of the ATLAS pixel and strip detectors.This damage has important implications for data-taking operations, charged-particle track reconstruction,detector simulations, and physics analysis. This talk presents simulations and measurements of the leakage current for the ATLAS pixel detector as a function of location in the detector...
The radiation hardness of detectors is of paramount importance for the success of the scheduled High Luminosity upgrade of the CERN Large Hadron Collider. This has driven a global campaign for sensor characterisation and irradiation testing facility qualification. The effect of radiation damage from various particle species and energies are conventionally communicated in term of the equivalent...
We report on the study of response of the MOS capacitor with atomic layer deposited (ALD) Al2O3 layer on p-type silicon substrate to neutron, proton, and gamma irradiation. Alumina films are prominent for use as passivation layers in silicon radiation detectors instead of surface electron accumulation termination structures as alumina forms negative oxide charge on the silicon-oxide interface....
During the era of the High-Luminosity (HL) LHC the experimental devices will be subjected to enhanced radiation levels with fluxes of neutrons and charged hadrons in the inner detectors up to ~2.3x$10^{16}$ n$_{eq}$/cm$^{2}$ and total ionization doses up to ~1.2 Grad. A systematic program of irradiation tests with neutrons and charged hadrons is being run by LHC collaborations in view of the...
This project focuses on the investigation of trap energy levels introduced by radiation damage in epitaxial p-type silicon. Using 6-inch wafers of various boron doping concentrations (1e13, 1e14, 1e15, 1e16, and 1e17 cm$^{-3}$) with a 50 µm epitaxial layer, multiple iterations of test structures consisting of Schottky and pn-junction diodes of different sizes and flavours are being fabricated...
During edge- and Top-TCT measurements using subsequent laser pulses with a pulse repetition time of several microseconds, a significant decrease in the measured signal amplitude has been observed.
The charge created during the pulses has severe effects on the electrical configuration of the sensor. This can be explained by either trapping of charge carriers which alter the charge...
The charge collection of two $\text{n}^+\text{p}^+\text{p}^+$ pad diodes has been measured using a $5 \; \text{GeV}$ electron beam (at DESY) entering from the $150 \; \mu \text{m}$ thick side edge side of diodes. Using the EUDAQ telescope it is possible to precisely reconstruct the beam position. The collected charge as a function of the beam position along the diode thickness is...
The already approved concepts of TCT-TPA and TCT-SPA (both developed within the RD50 Collaboration) have been brought by the RD50 Montenegro team to the pan-European Research Infrastructure and laser facility ELI Beamlines in March 2020. RD50 Montenegro team partnered with RD50 teams from Slovenia, Italy, and the Czech Republic. The idea was to build an additional research TCT infrastructure...
The first TPA signal in LGAD at the TPA/SPA experimental research station, that is under development at the premises of the research infrastructure and laser facility ELI Beamlines, is presented. The RD50 campaign at ELI’s site for the ELI fs- beam profile study and TPA signature was conducted in Oct/Nov 2020 and performed under the ELI User Call Framework after an application by...
By shrinking the sizes of detectors used in high energy physics experimental setups, techniques that can characterise detectors at the micrometer size levels are getting more and more attention. This may be one of the reasons why the Ruđer Bošković Institute (RBI) and its microprobe based IBIC (ion beam induced charge) system, attracted more than 20 users from the high energy physics community...
The PaRaDeSEC project “Particle and Radiation Detectors, Sensors and Electronics in Croatia“ is an ERA Chair Horizon 2020 in the EU Framework Programme for Research and Innovation. A national center for development of radiation particle detectors, sensors and their associated electronics was successfully established as a result of the PaRaDeSEC project. The new Center for Detectors, Sensors &...
We report on the measurements of time resolution for double-sided 3D pixel sensors with a single cell of 50 $\mu$m $\times$ 50 $\mu$m and thickness of 285 $\mu$m, fabricated at IMB-CNM and irradiated with reactor neutrons to 8e14 MeV n$_{eq}$/cm$^2$ and then to 2.3e15 MeV n$_{eq}$/cm$^2$. Measurements were conducted using a radioactive source at a temperature of -20 and 20 \textdegree C in a...
The ATLAS experiment High Granularity Timing Detector (HGTD) project has been approved as a part of the Large Hadrons Collider Phase-II Upgrade (HL-LHC). The Low- Gain Avalanche Detector (LGAD) with time resolution better than 50ps is the key technology to separate collisions in limited space which has been studied and researched by many institutes. This talk will present the simulation and...
First batch of LGAD devices, developed by RAL, University of Oxford, University of Birmingham and Open University in collaboration with T2ev semiconductor foundry, have been designed and fabricated for fast timing applications and potential use in HGTD for ATLAS.
Up to eight different LGAD device flavours, differing in energy and dose of the implanted gain layer, have been fabricated on 6’’...
We will present the preliminary test results of the USTC first batch LGAD, which is designed by USTC focusing on deep implantation and carbon diffusion techniques to improve the irradiation hardness. The design follows the ATLAS-HGTD specifications with 50 um active thickness and 8-inch wafers are used. In the first prototyping run, 6 wafer splits with different gain layer dose and...
A new Ultra Fast Silicon Detectors production (UFSD3.2) has been produced
by Fondazione Bruno Kessler (FBK) in Trento, in collaboration with
University of Trento and National Institute of Nuclear Physics in Turin
(INFN); this production aims to improve the radiation resistance of the
multiplication layer (gain layer).
Previous FBK-UFSD productions (UFSD2 and UFSD3) demonstrated that...
The performance of latest LGAD sensor prototypes from different producers were studied before and after irradiations with neutrons. The charge collection, timing and gain layer depletion voltages were compared.
We report on the first results of a mortality campaign on the Low Gain Avalanche Detectors (LGAD) produced by Hamamatsu (HPK) as prototypes for the High-Granularity Timing Detector (HGTD) in ATLAS. The study was conducted at the ELI Beamlines site during the ELI RD50 campaign as part of the ELI User Experiment that has been recently selected from the ELI User Call proposals. The HPK-P2 (WF25)...
The first production of thin LGAD sensors from FBK has been completed.
The preliminary electrical characterization of sensors before irradiation will be presented and discussed.
Low Gain Avalanche Diodes (LGADs) are characterised by a low to moderate gain (2 - 100), short rise time, high signal-to-noise ratio and exhibit excellent timing performance (30-40 ps), however fine pixelization of LGADs is difficult to achieve. To provide fine spatial resolution the AC-coupled LGAD (AC-LGAD) approach was introduced. In this type of device, the signal is capacitively induced...
Resistive readout allows designing thin sensors with a small material budget and excellent spatial resolution. In this contribution, I will present how exploiting the properties of AC-LGAD is it possible to reach a spatial precision of 1 um with large pixels (150-200 um), keeping the material budget low enough to meet the stringent requirement of the future e+e- experiments.
We describe and simulate a concept which combines small pixels enabled by 3D sensor-electronics integration with gain produced by a Low Gain Avalanche Diode (LGAD) layer (inverted LGAD). The detector is double-sided, with electrons collected by the cathode, which provides timing information, and an anode with small pixels to provide position and angle information. The cathode can be coarse...
A Sr-90 based beta- particle setup was developed and commissioned at CERN-SSD for measuring silicon sensors, specifically their timing properties. Herein, we detail what hardware is thereby deployed, how the setup is operated, as well as data processing and analysis of measurements, for which the open-source programs TRICS and ROOT are used.
The hardware, DAQ and analysis software of the JSI setup will be presented.
In this contribution, I will present the characterization of the latest LGAD productions manufactured at FBK (UFSD3.2) and HPK (HPK2), performed with the β-source (Sr90) setup of the Torino Silicon Lab (INFN – University of Torino). In particular, I will focus on temporal resolution and gain measurements of either irradiated (up to a fluence of 2.5E15 neq/cm2 ) and non-irradiated devices....
RD50-MPW2 is pixel detector prototype fabricated in 150 nm High Voltage CMOS technology at LFoundry. It is a successor of RD50-MPW1 chip developed within RD50 collaboration to study this technology for future experiments. Chips were manufactured on p-type silicon with different initial resistivities and irradiated with neutrons in reactor in Ljubljana. E-TCT and I-V measurements were made...
With the HL-LHC upgrade of the ATLAS detector, the surface of the ATLAS pixel detector will increase from 2 m² to approximately 13 m² . Therefore, commercial CMOS processing lines offering high production throughput at comparatively low costs, represent an attractive option for such large-area detectors. Further benefits originate from multiple metal layers, metal–insulator–metal capacitors,...
An increasing trend towards full silicon trackers in future high energy physics experiments provokes the need to cover increasingly large areas with silicon detectors. As a consequence, detector designs that utilize cost-effective production processes are becoming more important. Employing CMOS production lines for sensors allows large and high-resistive wafers at low cost, making them a prime...
The active matrix of the RD50 HV-CMOS MPW2 prototype consists of 8x8 pixels with analogue frontend only. While former measurements on irradiated sensors have been performed only at passive test-
structures, first results of the irradiated active matrix are discussed in this presentation. The test structures do have a similar layout than the active matrix, but only one pixel at a time can be...
So-called "passive CMOS" pixel and stript sensors using commercial CMOS chip fabrication lines have become an interesting alternative to standard planer sensors. An important question is how the resistance between electrodes changes as a function of irradiation fluence for various implant geometry. We present preliminary results on the measurements of the inter-pixel resistance of passive CMOS...
