Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
8166374 | Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment | 2018 | 10 Pages |
Abstract
Low Gain Avalanche Detectors (LGAD) are based on a n++-p+-p-p++ structure where an appropriate doping of the multiplication layer (p+) leads to high enough electric fields for impact ionization. Gain factors of few tens in charge significantly improve the resolution of timing measurements, particularly for thin detectors, where the timing performance was shown to be limited by Landau fluctuations. The main obstacle for their operation is the decrease of gain with irradiation, attributed to effective acceptor removal in the gain layer. Sets of thin sensors were produced by two different producers on different substrates, with different gain layer doping profiles and thicknesses (45, 50 and 80 μm). Their performance in terms of gain/collected charge and leakage current was compared before and after irradiation with neutrons and pions up to the equivalent fluences of 5â
1015 cmâ2. Transient Current Technique and charge collection measurements with LHC speed electronics were employed to characterize the detectors. The thin LGAD sensors were shown to perform much better than sensors of standard thickness (â¼300 μm) and offer larger charge collection with respect to detectors without gain layer for fluences <2â
1015Â cmâ2. Larger initial gain prolongs the beneficial performance of LGADs. Pions were found to be more damaging than neutrons at the same equivalent fluence, while no significant difference was found between different producers. At very high fluences and bias voltages the gain appears due to deep acceptors in the bulk, hence also in thin standard detectors.
Related Topics
Physical Sciences and Engineering
Physics and Astronomy
Instrumentation
Authors
G. Kramberger, M. Carulla, E. Cavallaro, V. Cindro, D. Flores, Z. Galloway, S. Grinstein, S. Hidalgo, V. Fadeyev, J. Lange, I. MandiÄ, G. Medin, A. Merlos, F. McKinney-Martinez, M. Mikuž, D. Quirion, G. Pellegrini, M. Petek, M. Zavrtanik,