Surface charge flow in two-dimensional position sensitive silicon detectors
Abstract
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. Position 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. It has been found that for a 2D-PSD with capacitance, C, and a ring resistance of {1}/{10 th} of surface resistance, R□, the position signals should be allowed to develop for ≈ {R □C }/{5} seconds in order to obtain 1% non-linearity (rms) in the position pattern, and the energy signal for longer than {2R □C }/{5} seconds for less than 1% ballistic deficit. A method is described that allows the model results to be used to correct position non-linearities that arise during experimental measurements.
- Publication:
-
Nuclear Instruments and Methods in Physics Research A
- Pub Date:
- February 1997
- DOI:
- 10.1016/S0168-9002(97)00974-1
- Bibcode:
- 1997NIMPA.399..365C