A new type of centroid finding method for position sensitive detectors

Abstract

A new method is introduced for determining the position of events in all detectors where the signals are collected through strips or wires or subdivided electrodes. Signals issued from a position-sensitive detector are processed to construct two pulses. Then, the position is determined by the time interval between these two waveforms. This method is a generalization of the delay line one used mostly in MWPC. However, the new method allows higher rates. The delay can be adjusted to smaller values (24 ns for our prototype). Tests were performed with 1D gas-filled detector with 100 mm length, designed for SAXS experiment at the ESRF synchrotron in Grenoble. The induced signal on a segmented cathode was collected through a resistor network similar to the charge division. The left and the right signals were used to determine the position using the new method based prototype. A spatial resolution of 0.67 mm at FWHM was obtained. Good linearity was achieved after correction of the U-distortion observed on a homogeneous irradiation of the detector.