Polarization of silicon detectors by minimum ionizing particles

This work presents quantitative predictions of the properties of highly irr adiated (e.g. by high-energy particles. up to an equivalent fluence of 1 x 10(14) n cm(-2)) silicon detectors operating at cryogenic temperature. It i s shown that the exposure to the Minimum Ionising Particle (MIP) with count ing rates of about 10(6) cm(-2) s(-1) can influence the electric field dist ribution in the detector's sensitive volume. This change in the electric fi eld distribution and its effect on the charge collection efficiency are dis cussed in the frame of a model based on trapping of carriers generated by M IPs. The experiment was performed at 87 K with an infrared (1030 nm) laser to simulate MIPs. (C) 2000 Elsevier Science B.V. All rights reserved.