Surface charge flow in two-dimensional position sensitive silicon detectors

A model has been constructed to study the electrode current characteristics of the resistive sheet type of two-dimensional position sensitive silicon detector (2D-PSD) including those with a low-resistance ring around the central high-resistance area. The 2D-PSD is modelled as a regular mesh of discrete resistors connected at their nodes via capacitors to a common plane; a solution of the individual node voltages for short time steps allows for a determination of the electrode currents. on reconstruction non-linearities and energy signal ballistic deficit have been investigated for various values of surface, ring and electrode termination resistances by integrating the current pulses from a simulated particle hit. been found that for a 2D-PSD with capacitance, C, and a ring resistance of 110th of surface resistance, R□, the position signals should be allowed to develop for ≈R□C5 seconds in order to obtain 1% non-linearity (rms) in the position pattern, and the energy signal for longer than 2R□C5 seconds for less than 1% ballistic deficit. od is described that allows the model results to be used to correct position non-linearities that arise during experimental measurements.