OPTIMIZATION OF THE PARTICLE DISCRIMINATOR BASED ON THE BALLISTIC DEFICIT METHOD USING DELAY-SWITCHED GATED INTEGRATOR

The particle discriminator we developed for CsI(TI) elements of an anc illary detector array planned to be used together with large gamma-ray detector systems utilizes the ballistic deficit effect for particle d iscrimination. This technique applies a low-ballistic-deficit long-tim e-constant unipolar semi-Gaussian shaper and a large-ballistic-deficit short-time-constant bipolar shaper. To match the signal processing ti me of our discriminator with that of the standard electronics for Ge d etectors the long-time-constant semi-Gaussian shaper was substituted w ith the so-called delay-switched gated integrator. The experimental te sts of the new arrangement show that the pulse processing time can be significantly shortened. The figure of merit of the particle discrimin ation improves with increasing the total integration time of the delay -switched gated integrator up to 12 mu s, above which the improvement is negligible. Therefore, this 12 mu s integration time is considered as a good compromise as for the figure of merit and the dead time of t he new arrangement.