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Radiation Damage

Session chair: Ottaviani , Laurent (Aix-Marseille University, IM2NP - UMR CNRS 7334, Marseille, France); Dalla Betta , Gian-Franco (University of Trento and INFN, Department of Industrial Engineering, Trento, Italy)
Shortcut: N-31
Date: Friday, 22 October, 2021, 7:00 AM - 8:45 AM
Room: NSS - 1
Session type: NSS Session


Click on an contribution to preview the abstract content.

7:00 AM N-31-01

X-ray Radiation Damage Effects on Double-SOI Pixel Detectors for the Future Astronomical Satellite (#185)

M. Kitajima1, T. Kohmura1, K. Hagino1, M. Hayashida1, K. Oono1, K. Yarita1, K. Negishi1, T. Doi1, S. Tsunomachi1, T. G. Tsuru2, H. Uchida2, K. Kayama2, R. Kodama2, T. Tanaka3, K. Mori4, A. Takeda4, Y. Nishioka4, M. Yukumoto4, K. Mieda4, S. Yonemura4, T. Ishida4, Y. Arai5, I. Kurachi6

1 Tokyo University of Science, Noda, Japan
2 Kyoto University, Kyoto, Japan
3 Konan University, Kobe, Japan
4 University of Miyazaki, Miyazaki, Japan
5 KEK, Tsukuba, Japan
6 D&S Inc., Tokyo, Japan


We have been developing the monolithic active pixel detector ''XRPIX'' onboard the future X-ray astronomical satellite ''FORCE''. XRPIX is composed of CMOS pixel circuits, SiO2 insulator, and Si sensor by utilizing the silicon-on-insulator (SOI) technology. When the semiconductor detector is operated in orbit, it suffers from the radiation damage due to X-rays emitted from the celestial objects as well as cosmic rays. From previous studies, positive charges trapped in the SiO2 insulator are known to cause the degradation of the detector performance. To improve the radiation hardness, we developed XRPIX equipped with Double-SOI (D-SOI) structure, introducing an additional silicon layer in the SiO2 insulator. This detector is aimed at compensating the effect of the trapped positive charges. Although the radiation hardness to cosmic rays of the D-SOI detectors has been evaluated, radiation effect due to the X-ray irradiation has not been evaluated. Then, we conduct an X-ray irradiation experiment using an X-ray generator with a total dose of ~ 10 krad, equivalent to ~ 7 years in orbit. As a result of this experiment, the energy resolution in full-width half maximum for the 5.9 keV X-ray degrades by 17.8 ± 2.8% and the dark current increases by 89 ± 13%. We also investigate the physical mechanism of the increase in the dark current using TCAD simulation. It is found that the increase in the surface recombination velocity at the Si-SiO2 interface causes the increase in the dark current.

Keywords: X-ray, SOI pixel, Astronomy, Radiation damage, Dark current
7:15 AM N-31-02

Radiation damage on SiPMs for Spatial Applications (#580)

A. R. Altamura1, 3, F. Acerbi1, B. Di Ruzza2, E. Verroi4, A. Mazzi1, A. Gola1

1 FBK, Trento, Italy
2 TIFPA - INFN (Italy), Trento, Italy
3 Universita' degli Studi di Udine, Udine, Italy
4 Universita' degli Studi di Trento, Trento, Italy


Silicon Photomultipliers are single-photon sensors working in Geiger mode. They are used in a wide range of applications, from high-energy physics to space and medical imaging. In some applications, they can be exposed to a significant amount of radiation, in the order of 1012−1014 neq/cmin high-energy physics or in the order of 109−1012 neq/cm2 in space for 5 years LEO orbits. In this contribution, we present an analysis of the main effects of the protons irradiation on the functional performance of several FBK SiPM technologies, with doses compatible with space missions along LEO orbits. In particular, we irradiated the SiPMs at the Protontherapy Center in Trento with proton fluences between 7.4×10neq/cm2 and 6.4×1011 neq/cm2. During the irradiation test, reverse current-voltage (I-V) measurements were performed on the devices after each fluence step, and key parameter as Dark Count Rate and Photon Detection Efficiency were estimated. An annealing test was conducted at room temperature on all the devices for one month, performing reverse I-V measurements once a day. Lastly, results are showed and conclusions are drawn.

Keywords: Radiation damage, SiPM, Protons
7:30 AM N-31-03

Simulation and Optimization of Irradiated Thin Low-Gain Avalanche Diodes (#485)

T. Croci1, 2, A. Morozzi2, F. Moscatelli3, 2, P. Asenov3, 2, V. Sola4, G. Borghi5, G. Paternoster5, M. C. Vignali5, D. Passeri1, 2

1 University of Perugia, Department of Engineering, Perugia, Italy
2 INFN, Section of Perugia, Perugia, Italy
3 CNR-IOM, Perugia, Italy
4 INFN, Section of Torino, Torino, Italy
5 FBK, Trento, Italy


In this work, the results of Technology-CAD (TCAD) device-level simulations of non-irradiated and irradiated Low-Gain Avalanche Diode (LGAD) detectors will be presented. Since LGADs are becoming one of the most promising devices for high performance in harsh radiation environments, it is of the utmost importance to have a predictive insight into their electrical behavior and charge collection properties up to the highest particle fluences reachable, for example, in the future High Energy Physics (HEP) experiments. To this purpose, state-of-the-art Synopsys Sentaurus TCAD tools have been adopted and equipped with a well-validated radiation damage numerical model, called the “University of Perugia model”, coupling it with an analytical one that describes the mechanism of acceptor removal in the multiplication layer after the LGAD being irradiated. Thanks to this, it has been possible to reproduce experimental data with high accuracy, demonstrating the reliability of the implemented simulation framework. Moreover, the good agreement obtained between simulation results and experimental data has allowed us to apply the newly developed model not only for the prediction of the behavior but also for the optimization of the new thin LGAD detectors fabrication run at the Fondazione Bruno Kessler (FBK) facility.

AcknowledgmentThe authors acknowledge funding from the Italian PRIN MIUR 2017 (Research Project “4DInSiDe” - Innovative Silicon Detectors for particle tracking in 4Dimensions).
Keywords: LGAD, radiation damage effects, radiation hardness, TCAD numerical simulations.
7:45 AM N-31-04

First results from thin silicon sensors irradiated to extreme fluences (#857)

V. Sola1, R. Arcidiacono1, 2, P. Asenov3, 4, G. Borghi5, 6, M. Boscardin5, 6, N. Cartiglia1, M. Centis Vignali5, T. Croci4, 7, M. Ferrero1, 2, G. Gioachin8, S. Giordanengo1, M. Mandurrino1, L. Menzio1, 8, A. Morozzi4, F. Moscatelli3, 4, D. Passeri4, 7, G. Paternoster5, 6, F. Siviero1, 8, M. Tornago1, 8

1 Istituto Nazionale di Fisica Nucleare, Sezione di Torino, Torino, Italy
2 Università degli Studi del Piemonte Orientale, Dipartimento di Scienze del Farmaco, Novara, Italy
3 CNR-IOM, Sede secondaria di Perugia, Perugia, Italy
4 Istituto Nazionale di Fisica Nucleare, Sezione di Perugia, Perugia, Italy
5 Fondazione Bruno Kessler, Centro Materiali e Microsistemi, Trento, Italy
6 TIFPA-INFN, Trento, Italy
7 Università degli Studi di Perugia, Dipartimento di Ingegneria, Perugia, Italy
8 Università degli Studi di Torino, Dipartimento di Fisica, Torino, Italy


In this contribution, we present a new development of radiation-resistant silicon sensors produced by the Fondazione Bruno Kessler (FBK, Italy). The design of the sensors exploits the recently observed saturation of radiation damage effects on silicon, together with the usage of thin substrates, intrinsically less affected by radiation. To cope with the small signal coming from thin sensors, internal multiplication of the charge carriers will be used. At FBK, Low-Gain Avalanche Diodes (LGAD) have been produced on 25 and 35 mm thick p-type epitaxial substrates: when new, the signal multiplication will occur due to the gain layer typical of the LGAD design; after irradiation, the loss of gain resulting by the deactivation of the gain layer atoms will be compensated by a moderate increase of the operating bias. The goal is to pave the way for a new sensor design that can efficiently operate up to fluences of 1x1017 1MeV neutron equivalent/cm2.


Part of this work has been financed by the European Union’s Horizon 2020 Research and Innovation funding program, under Grant Agreement no.654168 (AIDA-2020) and Grant Agreement no.669529 (ERC UFSD669529), and by the INFN CSN5, under INFN Young Researcher Grant eXFlu. This work is partially performed within the CERN RD50 Collaboration, and in collaboration with the Fondazione Bruno Kessler, Trento.

Keywords: Silicon, Silicon radiation detectors, Radiation hardening, Particle tracking, LGAD
8:00 AM N-31-05

Displacement damage in Hydrogenated Amorphous Silicon p-i-n diode and charge selective contacts detectors (#928)

M. Menichelli1, M. Bizzarri1, 2, M. Boscardin3, 4, L. Calcagnile5, M. Caprai1, A. P. Caricato5, G. A. P. Cirrone6, M. Crivellari4, I. Cupparo7, G. Cuttone6, S. Dunand8, L. Fanò2, 1, O. A. Hammad4, M. Ionica1, K. Kanxheri1, M. Large10, G. Maruccio5, A. G. Monteduro5, F. Moscatelli1, 9, A. Morozzi1, A. Papi1, D. Passeri11, 1, M. Petasecca10, G. Quarta5, S. Rizzato5, A. Rossi2, 1, G. Rossi1, A. Scorzoni11, 1, L. Servoli1, C. Talamonti7, G. Verzellesi12, 3, N. Wyrsch8

1 INFN, Sezione di Perugia, Perugia, Italy
2 Università di Perugia, Dipartimento di Fisica e Geologia, Perugia, Italy
3 INFN, TIPFA, Trento, Italy
4 Fondazione Bruno Kessler, Department of Microelectronics, Povo (TN), Italy
5 INFN and Università del Salento, Sezione di Lecce, Lecce, Italy
6 INFN, LNS, Catania, Italy
7 INFN and Università di Firenze, Sezione di Firenze, Firenze, Italy
8 EPFL, Institute of Microengeneering, Neuchatel, Neuchâtel, Switzerland
9 CNR, IOM, Perugia, Italy
10 University of Wollongong, Centre for Medical Physics, Wollongong, Australia
11 Università di Perugia, Dipartimento di Ingegneria, Perugia, Italy
12 Università di Modena e Reggio Emilia, Dipartimento di scienze e metodi dell'ingegneria, Reggio Emilia, Italy


Hydrogenated amorphous silicon is a well known detector material for radiation resistance. This study present 10 µm thickness, p-i-n and charge selective contacts diode detectors which will be irradiated with neutrons at two fluence values: 1016 neq/cm2 and 5 x 1016 neq/cm2. In order to evaluate their radiation resistance detector leakage current, and response to X-ray photons will be measured. The effect of annealing for partial performance recovery at 100°C for 12 and 24 hours will also be studied. These data will be included in the Hydrogenated amorphous silicon simulation code running under the framework of the TCAD Synopsis program.


This  work was partially supported by the “Fondazione Cassa di Risparmio di Perugia” RISAI project n. 2019.0245.

Keywords: Hydrogenated Amorphous Silicon, Particle detectors, Radiation damage, Solid state detectors, X-rays detectors
8:15 AM N-31-06

Performance of Highly Irradiated SiPMs Coupled toLYSO:Ce Crystals for the CMS MTD BarrelTiming Layer (#889)

C. E. Pérez Lara1

1 University of Virginia, Department of Physics, Charlottesville, Virginia, United States of America

On behalf of the CMS Collaboration


The MIP Timing Detector is a new detector being developed for the CMS upgrade for the High Luminosity LHC era. The detector will bring the capability of measuring precisely the production time of particles generated in proton-proton collisions. In particular the MTD will allow for the disentangling of the estimated 200 nearly simultaneous pileup vertices that occur in the interaction diamond at each bunch crossing during high luminosity operation. The central Barrel Timing Layer of this detector will consist of an array of LYSO:Ce crystals coupled to SiPMs able to provide unprecedented time resolution under such conditions (30 ps). One of the important challenges that the detector will face is to keep its good performance (< 60 ps) during the lifetime of the experiment. It has been shown that the performance of SiPMs is affected when they are exposed to high level of radiation. In order to quantify the impact of radiation to our prototype, we irradiated three pairs of SiPMs to different levels of 1 MeV neutron equivalent fluence comparable to those expected at the end of life conditions. We report on the preliminary performance results of time resolution measured in the laboratory and with test beam of our detector prototype.

Keywords: CMS, MTD, BTL, Timing, Radiation
8:30 AM N-31-07

Energy dependence of the acceptor removal by protons for several UFSD types (#1146)

H. Sadrozinski1

1 University of California, Santa Cruz, Santa Cruz Institute for Particle Physics (SCIPP), Santa Cruz, California, United States of America

On behalf of the UFSD Collaboration UC Santa Cruz - INFN Torino


The performance of Ultra-Fast Silicon Detectors (UFSD) is compromised by hadronic irradiation which removes the acceptors in the thin layer below the junction responsible for the gain. This effect is measured in several different UFSD after irradiation with protons with energy of 70 MeV (CYRIC), 800 MeV (LANL) and 24 GeV (CERN) and compared to the same sensors irradiated with neutrons at IJS. The fluence dependence is determined with capacitance – voltage, C-V, measurements of the doping concentration and with measurements of charge collection, CC, using charged particles. We find that the simplified assumption of NIEL scaling does not apply to the acceptor removal mechanism which exhibits a larger effect for protons than predicted by NIEL.


This work was supported by the United States Department of Energy, grant DE-FG02-04ER41286.

Part of this work has been financed by the European Union’s Horizon 2020 Research and Innovation funding program, under Grant Agreement no. 654168 (AIDA-2020) and Grant Agreement no. 669529 (ERC UFSD669529), and by the Italian Ministero degli Affari Esteri and INFN Gruppo V.  
This work was partially performed within the CERN RD50 collaboration.


Keywords: Silicon detectors, Ultra-Fast Silicon Detectors, Fast Timing, Radiation Damage

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