CHARGE WAVEFORM OF A NEW TWO-DIMENSIONAL POSITION-SENSITIVE SILICON DETECTOR.

The operation principles of the two-dimensional position-sensitive silicon detector newly developed by T. Doke et al. were studied using a simple model. This model treats the detector as an area of continuously distributed capacitance C and resistance R//s of position surface layer. A linear relationship can then be obtained between the position of the incident particle and charge collected at the corner contacts of the detector. The kinetics of charge collected at corner contacts, ballistic deficit and noise were calculated. Rise time of the charge pulse (10-90 percent) was found to vary with the position of incidence up to about R//sC/8. It was found that a shaping time constant longer than R//sC/3 is required for pulse shaping with single CR-differentiation and single CR-integration in order to obtain a ballistic deficit of less than 1 percent.