The electric field in irradiated silicon detectors

The electric field distribution inside heavily irradiated silicon particle detectors is deduced using observations of α particle and minimum ionising particle signals. In these detectors α particle signals are observed for both p+ and n+ side illumination even when the detector is only partially depleted. The observations indicate that the electric field distribution within the partially depleted detector has the contribution expected from a uniform space charge, as in unirradiated detectors, together with a strong, short range, local electric field in the vicinity of the p+ electrode and a non-zero electric field in the remaining part of the detector.