Optimization of the position resolution in semiconductor detectors

In our effort to image the cloud of mobile charge-carriers induced by a radiation interaction in a solid-state material, we have performed a fundamental investigation of the electrode design and pulse shape analysis routines required to optimize the detector's position resolution, when limited by both temporal and carrier uncertainty. The interactions of ions and gamma-rays with silicon are modeled using Monte Carlo techniques so that the currents induced on the measurement electrodes can be predicted. Those predictions are then compared to the measured results derived from a high-resistivity silicon detector, on which metal-semiconductor junctions are used to form the rectifying and ohmic contacts.