Title Characteristics of gain degradation in proton irradiated Low Gain Avalanche Detectors
Authors Čeponis, Tomas ; Biveinytė, Margarita ; Deveikis, Laimonas ; Gaubas, Eugenijus ; Pavlov, Jevgenij ; Rumbauskas, Vytautas ; Tamošiūnas, Vincas ; Žilinskas, Kęstutis
DOI 10.1088/1748-0221/20/08/C08029
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Is Part of Journal of instrumentation: 20th anniversary Trento Workshop on Advanced Silicon Radiation Detectors (TREDI2025), Trento, Italy, 4–6 February 2025.. Bristol : IOP Publishing. 2025, vol. 20, iss. 8, p. [1-11].. eISSN 1748-0221
Keywords [eng] charge transport and multiplication in solid media ; particle tracking detectors (solid-state detectors) ; radiation damage to detector materials (solid state) ; radiation-hard detectors
Abstract [eng] Low Gain Avalanche Detectors (LGADs) provide high time resolution at moderate charge gain, making them essential for high-energy physics experiments, such as those at the High Luminosity Large Hadron Collider. However, their performance is significantly impacted by radiation induced defects, particularly at high hadron fluences. This study is devoted to the characterization of degradation mechanisms in LGADs irradiated with 24 GeV/c protons at fluences ranging from 1012 to 1016 cm-2. Carrier lifetime (τR ) variations examined using the microwave probed photoconductivity transients revealed a significant reduction of τR from >10 μs in non-irradiated samples to <1 ns at the highest fluence irradiated sensors, indicating increased densities of defects acting as deep-level recombination centers. Photoionization and deep level transient spectroscopy techniques have been employed to identify radiation induced defects. The impact of these defects on the electric field distribution and internal gain in LGADs was comprehensively analyzed using Synopsys TCAD Sentaurus and MATLAB simulations. The results indicate a substantial reduction in gain from 26 for non-irradiated sensors to a negligible its value for 1016 cm-2 fluence irradiated LGADs due to a simultaneous reduction of effective doping concentration, decreased τR and enhanced trapping. The study provides a versatile methodology for correlating electrical and spectroscopic measurements with defect characterization, offering valuable insights for optimizing LGAD design in radiation-rich environments.
Published Bristol : IOP Publishing
Type Journal article
Language English
Publication date 2025
CC license CC license description