4th DRD3 week on Solid State Detectors R&D

Session

WG3/WP3 - Extreme fluence and radiation damage characterization

12 Nov 2025, 10:50

6/2-024 - BE Auditorium Meyrin (CERN)

6. Gain-Layer Project

Niels Sorgenfrei (CERN / University of Freiburg (DE))

12/11/2025, 11:25

WG3 Radiation Damage - Extreme Fluence

The study of radiation damage created inside the gain-layer of LGADs is nearly impossible with defect spectroscopy techniques.
To investigate the gain-layer degradation at the defect level, the Gain-Layer Project has produced an extensive set of $p$-type pad diodes (19050 in total), whose bulk properties replicate the high doping concentrations of a gain layer.
Across 25 FZ wafers, various...

46. Study of Irradiation-Induced Defects in EPI silicon PINs and LGADs by c/iDLTS

Dr Yunyun Fan (Chinese Academy of Sciences (CN))

12/11/2025, 11:55

WG3 Radiation Damage - Extreme Fluence

Low Gain Avalanche Detectors (LGADs) exhibit excellent properties, including ultra-fast time resolution and a high signal-to-noise ratio. They are widely used in high-energy physics experiments for precise particle detection and time-of-flight measurements. However, irradiation introduces deep-level defects and causes detector performance degradation. Therefore, improving the radiation...

20. Optical detected magnetic resonance (ODMR) of $A$$_{Si}$-Si$_{i}$-defects: case of acceptor indium

Kevin Lauer (CIS Institut fuer Mikrosensorik GmbH (DE))

12/11/2025, 12:15

WG3 Radiation Damage - Extreme Fluence

Kevin Lauer,$^{1,2}$ Bernd Hähnlein,$^{1}$ Mario Bähr,$^{1}$ Kai Kühnlenz,$^{1}$ Phillipp Kellner,$^{1}$ Dirk Schulze,$^{2}$ Stefan Krischok,$^{2}$ Alexander Rolapp,$^{3}$ Christian Möller$^{1}$ and Thomas Ortlepp$^{1}$

$^{1}$ CiS Forschungsinstitut für Mikrosensorik GmbH, Konrad-Zuse-Str. 14, 99099 Erfurt, Germany
$^{2}$ Technische Universität Ilmenau, Institut für Physik, Weimarer Str....

30. Study of radiation damages at extreme fluences by Infrared Spectroscopy

Dr Faiza Rizwan (CERN)

12/11/2025, 12:35

WG3 Radiation Damage - Extreme Fluence

Study of Si detectors for radiation tolerance at extreme fluences up to 1e18 neq/cm2 has been suffering with numerous challenges. Defects created in the crystal lattice, compensate the doping by trapping the free charge carriers, causing the depletion region to collapse. Resultantly, the electrical defect characterization tools become ineffective. This moves our attention towards the optical...

38. Investigation of point defects in silicon supercells using density functional theory

George Alexandru Nemnes (Horia Hulubei National Institute for R&D in Physics and Nuclear Engineering)

12/11/2025, 14:20

WG3 Radiation Damage - Extreme Fluence

Neutral and charged point defects in silicon supercells containing vacancies and/or extrinsic impurities (B, P, C, O) are investigated using density functional theory (DFT) calculations. We consider a number of defects and determine the formation energies and the transitions between the charged states. The electronic structure is analyzed in detail, the focus being on defects that can explain...

39. Donor removal and Global Gain Quenching (GGQ) in nLGAD detectors

Milos Manojlovic (Consejo Superior de Investigaciones Cientificas (CSIC) (ES))

12/11/2025, 14:40

WG3 Radiation Damage - Extreme Fluence

nLGAD detectors are specifically designed for detecting shallow-penetrating radiation. In our previous work, we tested these devices using low-wavelength lasers and achieved reasonable detectability down to 200 nm. In this work, we explore the potential of nLGADs for the detection of shallow-penetrating ions, aiming to evaluate their gain and response to induced damage. Using Ion Beam Induced...

32. Radiation hardness and annealing studies of double irradiated silicon diodes produced on 8-inch wafers for CMS HGCAL

Max Andersson (Uppsala University (SE))

12/11/2025, 15:00

WG3 Radiation Damage - Extreme Fluence

To face the higher levels of radiation due to the 10-fold increase in integrated luminosity during the High Luminosity LHC, the CMS detector will replace the current endcap calorimeters (CE) with the new High Granularity Calorimeter (HGCAL). It will facilitate the use of particle flow calorimetry with its unprecedented transverse and longitudinal readout and trigger segmentation, with more...

60. Studies of surface radiation damage with CMS HGCAL test diodes

Eva Fialova (CERN)

12/11/2025, 15:50

WG3 Radiation Damage - Extreme Fluence

Studies of the silicon dioxide (SiO$_2$) passivation layer in HGCAL's n-on-p sensors are important for qualifying their performance at the High-Luminosity LHC and for optimising the operation of future high-energy physics experiments. This work presents a novel method to evaluate the impact of the surface radiation damage on the inter-pad isolation in HGCAL sensors, by measuring the threshold...

8. Leakage current evolution in LHCb VELO sensors during Run 1-2 LHC data taking period.

Agnieszka Oblakowska-Mucha (AGH University of Krakow (PL))

12/11/2025, 16:10

WG3 Radiation Damage - Extreme Fluence

The data-taking period of LHC Run 2 was finished at the end of 2018, providing an opportunity to study radiation damage effects in the LHC's most heavily irradiated silicon devices. In this presentation, we discuss new analyses of the evolution of the leakage current in the LHCb VELO sensors, accompanied by predictions from the Hamburg model. The leakage current's radial and longitudinal...

36. Annealing effects on highly n-doped layers in Resistive AC-coupled Silicon Detectors (RSD/AC-LGAD)

Aurora Losana (università di Torino), Brendan Regnery (KIT - Karlsruhe Institute of Technology (DE))

12/11/2025, 16:30

WG3 Radiation Damage - Extreme Fluence

Resistive AC-coupled Silicon Detectors (RSD/AC-LGAD) are novel silicon sensors that provide both precise spatial and temporal resolution, making them a key technology for the next generation of collider experiments (HL-LHC, FCC, CEPC). Like all silicon devices, these sensors suffer from irradiation damage which create additional states in the silicon band gap that lead to macroscopic changes,...

1. Response of AC-coupled Low Gain Avalanche Detectors to Ionizing and Non-ionizing Radiation Damage

Jiahe Si (University of New Mexico (US))

12/11/2025, 16:50

WG3 Radiation Damage - Extreme Fluence

Low gain avalanche diodes with DC- and AC-coupled readout were exposed to ionizing and non-ionizing radiation at levels relevant to future experiments in particle, nuclear, and medical physics and to astrophysics. Damage-related change in their acceptor removal constants and in the resistivity of the region between the guard ring and the active area are reported, as is change in the leakage...

41. Defect investigation on n-type Schottky diodes based on 4H-SiC before and after irradiation with 6 MeV electrons

Andra-Georgia Boni (National Institute of Materials Physics – Romania)

12/11/2025, 17:10

WG3 Radiation Damage - Extreme Fluence

We present the results of DLTS investigation of as-grown and radiation-induced defects in n-type 4H-SiC Schottky diodes irradiated with different fluences of 6 MeV electrons. The only variable between the samples has been the irradiation fluence, varying from unirradiated state up to fluences as high as 6E14 e/cm2. The DLTS spectra were analyzed and simulated to extract the defect...

76. WG3 - Updates and Discussion

Ioana Pintilie (National Inst. of Materials Physics (RO)), Dr Joern Schwandt (Hamburg University (DE))

12/11/2025, 17:30

62. Annealing of radiation defects in 8” silicon sensors for CMS HGCAL

Gizem Gul Dincer (KIT - Karlsruhe Institute of Technology (DE))

WG3 Radiation Damage - Extreme Fluence

To withstand the much higher radiation levels resulting from a tenfold rise in integrated luminosity at the High-Luminosity LHC, the CMS experiment will upgrade its existing endcap calorimeters (CE) with the new High Granularity Calorimeter (HGCAL). This detector will enable particle-flow calorimetry through its exceptionally fine transverse and longitudinal segmentation for both readout and...