LINEARITY WITH DOSE-RATE OF LOW-RESISTIVITY P-TYPE SILICON SEMICONDUCTOR-DETECTORS

Semiconductor detectors based on p-type silicon but with different dop ing levels have been investigated. The linearity response with dose ra te (dose per pulse in a pulsed beam), the sensitivity drop and the sen sitivity variation with temperature have been investigated after preir radiation, radiation damage, in different radiation qualities. It was shown that a p-type detector with a low doping level, high resistivity , showed a non-linear dose rate response if radiation damaged in a hig h energy photon beam, which contains neutrons. By increasing the dopin g level it was shown that a detector with a resistivity of 0.2 OMEGAcm stayed linear after preirradiation in radiation fields from high ener gy electrons, photons and protons. Other parameters did not show any c hanges of clinical importance at the different doping levels.