Montecarlo Simulation of Charge Collection Time in Closed Ended HP Ge Gamma Detectors

Charge collection dynamics for gamma radiation in closed ended HP Ge detectors is numerically computed by means of a Montecarlo simulation. The resulting collection time spectra for different bias voltages are then compared with the ones obtained for true coaxial detectors. The geometrical shape of closed ended detectors affects charge collection times mainly for weakly energetic gamma rays and low bias voltages, adding both a slow and a fast tail to time spectra.