Evaluation of characteristics of Hamamatsu low-gain avalanche detectors
Sayaka Wadaa, Kyoji Ohnarua, Kazuhiko Haraa, Junki Suzukia, Yoshinobu Unnob, Koji Nakamurab, Kazunori Hanagakib, Yoichi Ikegamib, Kazuhisa Yamamurac, Shintaro Kamadac, Yuhei Aboc, Hitomi Tokutaked, Daiki Yamamotoe
Nuc. Instr. Meth. A , Volume 924, 21 April 2019, Pages 380-386

Abstract: Low-gain avalanche detectors (LGADs) are attractive because of their fast response to realize a 4-dimensional (4D) tracker in future experiments in high energy physics and other applications. We fabricated LGAD diodes and strip sensors. Their responses before and after irradiation to gamma rays or neutrons were evaluated with light-emitting diodes (LEDs) of various wave lengths and with an infrared laser. The sensors showed a gain of more than 10 before irradiation. Little reduction of gain was observed with gamma irradiation. A substantial reduction of gain was observed after neutron irradiation. A gain increase observed in the interstrip region after neutron irradiation, whereas the gain was equal to one before irradiation.

Radiation tolerance study on irradiated AC-coupled, poly-silicon biased, p-on-n silicon strip sensors developed in India
S. Kuehn, T. Barber, G. Casse, P. Dervan, A. Driewer, D. Forshaw, T. Huse, K. Jakobs, U. Parzefall
Nuc. Instr. Meth. A , Volume 913, 1 January 2019, Pages 97-102

Abstract: The silicon sensors to be deployed in the next generation high energy physics experiments for operation in high luminosity scenarios, will require a high level of radiation tolerance. AC-coupled silicon strip sensors integrated with biasing poly-silicon resistors have been fabricated in collaboration with the Bharat Electronics Limited foundry using 4 inch n-type wafers in p-on-n configuration. Several sensors were irradiated with protons at different fluences at the Karlsruhe Cyclotron facility under the Advanced European Infrastructures for Detectors at Accelerators (AIDA) program. This paper reports on these radiation hardness study performed on the AC-coupled silicon sensors fabricated in India. The characterization comprises of electrical tests, including total current, voltage and strip scans and charge collection studies.

Energy loss of protons from MedAustron in silicon strip sensors
P. Paulitsch, T. Bergauer, D. Blöch, A.Burker, M. Dragicevic, J. Großmann, V. Hinger, A. Hirtl, A. König, F. Ulrich-Pur
Nuc. Instr. Meth. A, Volume 958, 1 April 2020, 162280

Abstract: MedAustron is a hadron synchrotron primarily designed and built for tumor treatment. Besides its clinical purpose, it is equipped with a dedicated beam line for non-clinical research. This beam line can be used for beam tests utilizing protons with an energy up to 252.7 MeV at the moment, but 800 MeV protons and carbon ions will become available through 2019. We conducted first beam tests at MedAustron in order to understand the usability of this beam line for testing silicon detectors. This includes the design and commissioning of a trigger setup based on scintillators and PMTs, which is meant to stay permanently there. This allowed us to measure energy deposition utilizing silicon strip sensors read out by the ALiBaVa system. Nominal beam energies were varied between 62.4 and 252.7 MeV and verified by determining the specific energy loss of protons in silicon. As these energies are rather low compared to typical HEP beam tests, the proton beam through the setup was simulated to determine the necessary energy correction due to losses through matter and air in front of the Si sensor. These approaches yielded good agreement with reference data from NIST, so MedAustron is considered as a reliable facility for future beam tests.

Characterization of Si Detectors
Ajay Kumar Srivastava

Abstract: The LHC (LARGE HADRON COLLIDER) at CERN, Geneva is one of the prestigious High-Energy physics (HEP) collider experiment. The LHC (pp Collider, 14 TeV, 25 ns bunch spacing) is foreseen to be upgraded to HL-LHC , where the luminosity increases of up to ten times i.e., 1035 cm−2 s−1 [1, 2]. At HL-LHC up to 400 interactions per bunch crossing are expected. This causes a major increase in track density, requiring for intermediate and larger radii smaller detection elements with higher granularity than the present the CMS silicon tracker. The radiation damage effects in the Si sensors at HL-LHC will be more challenging to cope with such hostile radiation environment therefore the Compact Muon Solenoid (CMS) experiments will require a new CMS tracking detectors in the phase 2 upgrade (2026) of the HL-LHC.

Characterization of FBK small-pitch 3D diodes after neutron irradiation up to 3.5 × 1016 neq cm−2
R. Mendicino, M. Boscardin, and G.-F. Dalla Betta

Abstract: We report on the characterization by a position resolved laser system of small-pitch 3D diodes irradiated with neutrons up to an extremely high fluence of 3.5 × 1016 neq cm−2. We show that very high values of signal efficiency are obtained, in good agreement with the geometrical expectation based on the small values of the inter-electrode spacings, and also boosted by charge multiplication effects at high voltage. These results confirm the very high radiation tolerance of small-pitch 3D sensors well beyond the maximum fluences expected at the High Luminosity LHC.

The upgraded microstrip silicon sensor characterization facility of the University of Sheffield
Kourlitis, E, Lohwasser, K, French, R, Edwards, S.O.

Abstract: A major component of the ATLAS Phase-II upgrade is the Inner Tracker, an all-silicon detector featuring novel microstrip sensors. Motivated by the current research efforts in silicon sensor technology, a characterization facility has been recently upgraded at the University of Sheffield. A description of the facility along with initial benchmark measurements of sensors before and after their irradiation are presented. The results were found to be in agreement with similar measurements conducted by other facilities in the UK and support the successful commissioning of the facility.