Analysis of a Charge-Sensitive Preamplifier Circuit with an Improved Time Resolution

A scheme of a charge-sensitive preamplifier (CSP) for measuring the energy and time of flight of detected particles is described. The CSP has two outputs. At the E-output, the signal is determined by the integral of the charge formed by a particle in a semiconductor detector. The signal amplitude at this output is proportional to the particle energy. At the T-output, the signal follows the shape of the detector current pulse and has a short rise time, which reduces the timing error. A circuit diagram of the CSP is shown, and calculations of the signal parameters at the E and T outputs are given. The results of modeling and the measured parameters of the proposed scheme are presented. The criterion of the expediency of using the time channel of the CSP depending on the radiation time of the radiator crystal or the charge collection time is obtained. The CSP is intended for use in photon spectrometers based on PWO crystals and avalanche photodiodes, but it can also be used in spectrometers with other types of semiconductor detectors.