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

The current damage parameter, α and the acceptor damage factor, β, 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 ± 0.03)×10¹⁴ pcm^-2 and at PSI with pions of energy 191 MeV up to a fluence of (4.5 ± 0.5)×10¹⁴ πcm^-2. In this paper we describe the irradiation setup and present the analysis that is used to extract the damage factors. The values of α normalized to 20°C from the proton and pion irradiations are: α_p=(4.84 ± 0.13)×10^-17 Acm^-1 and α_π=(1.2 ± 0.2)×10^-16 Acm^-1 respectively. The values of β from the proton and pion irradiations are β_p=0063 ± 0.0018 cm^-1 and β_π = 0.07 ± 0.02 in the temperature range -7° to -10°C. The ratio of current damage factors is: 2.5 ± 0.4 and agrees with the ratio of calculated non-ionising energy loss.