Si detector macroscopic damage parameters during irradiation from measurements of dark current evolution with fluence

The current damage parameter, /spl alpha/ and the acceptor damage factor, /spl beta/, of silicon detectors are extracted from an analysis of the evolution of the detector dark current during irradiation. The irradiations were carried out in the CERN PS 23GeV proton beam up to a fluence of (3.00 /spl plusmn/ 0.03)/spl times/10/sup 14/ pcm/sup -2/ and at PSI with pions of energy 191 MeV up to a fluence of (4.5 /spl plusmn/ 0.5)/spl times/10/sup 14/ /spl pi/cm/sup -2/. In this paper we describe the irradiation setup and present the analysis that is used to extract the damage factors. The values of /spl alpha/ normalized to 20/spl deg/C from the proton and pion irradiations are: /spl alpha//sub p/=(4.84 /spl plusmn/ 0.13)/spl times/10/sup -17/ Acm/sup -1/ and /spl alpha//sub /spl pi//=(1.2 /spl plusmn/ 0.2)/spl times/10/sup -16/ Acm/sup -1/ respectively. The values of /spl beta/ from the proton and pion irradiations are /spl beta//sub p/=0063 /spl plusmn/ 0.0018 cm/sup -1/ and /spl beta//sub /spl pi// = 0.07 /spl plusmn/ 0.02 in the temperature range -7/spl deg/ to -10/spl deg/C. The ratio of current damage factors is: 2.5 /spl plusmn/ 0.4 and agrees with the ratio of calculated non-ionising energy loss.