Calculated Gamma Ray Response Characteristics

A Monte Carlo computer program has been used to calculate characteristics of the response of fully depleted silicon and germanium radiation detectors to monoenergetic gamma rays. Data for total absorption probability, intrinsic efficiency, escape peak efficiency and pulse height spectra are presented as functions of detector thickness and photon energy. Other parameters of interest in analysing detector response are also given. The results of a second Monte Carlo calculation of electron migration in silicon and germanium are employed to account for the leakage of secondary electrons from the detector volume. Bremsstrahlung energy loss by electrons is also simulated. The calculations are expected to be applicable in those cases in which secondary electron energies do not exceed 2 MeV. Comparison with experiment shows good agreement within this limitation.