2019/11/28 by R. Klanner, J. Schwandt, Klanner, Robert +1
Engineering · Physics and Astronomy · #FOS: Physical sciences #Instrumentation and Detectors (physics.ins-det) #Particle Detector Development and Performance #Radiation Detection and Scintillator Technologies #Radiation Effects in Electronics
paper · pdf · doi:10.48550/arxiv.1911.12633
openalex publication_date 2019/11/28 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
In this paper the weighting field EW and the frequency dependence of the admittance Y of n+p pad sensors irradiated by 24 GeV/c protons to equivalent fluences in the range Φ\rm eq = 3 to 13× 1015 cm-2 are investigated. 1-D TCad simulations are used to calculate EW. For Φ\rm eq < 1013 cm-2 EW depends on position and time. However, for higher Φ\rm eq the time constant τ is much longer than the typical electronics readout time and EW = 1/d (d = sensor thickness). It is demonstrated that the increase of the resistivity of the Si bulk with irradiation is responsible for the increase of τ. The admittance Y of irradiated pad sensors has been measured for frequencies between f = 100 Hz and 1 MHz and voltages between 1 and 1000 V at -20^∘C and -30^∘C. For f < 1 kHz the parallel capacitance Cp shows a f dependence. A model with a position-dependent resistivity is able to describe the data. It is concluded: 1. The weighting field of a highly irradiated sensor is the same as the weighting field of a fully depleted sensor before irradiation. 2. Models with a position-dependent resistivity describe the frequency dependence of Cp for irradiated sensors.