Charge collection efficiency and current pulses in GaAs detectors

A model for the electric field distribution in semi-insulating GaAs detectors is developed and used to calculate charge collection efficiencies and current pulses generated by α-particles. Comparison with experiment results in estimated electron trapping times of 3 ns in the high electric field region of the detector. It is predicted that the trapping rate will be proportional to the net density of shallow acceptors in the GaAs.