An improved operating mode for a Si(Li) X-ray spectrometer

A novel technique has been developed for restoring the charge to the feedback capacitor in charge-sensitive preamplifiers. the method, transient-reset, was developed for use in very-low-noise Si(Li) X-ray spectrometers. It has proved valuable as a diagnostic tool for evaluating the noise components of the input circuit in these systems. The technique is described and compared with the pulsed-light and transistor-reset methods. To complement the charge restoration technique, a new configuration of Si(Li) X-ray detector with a very thin aluminum entrance window has been developed. Measurements of the effective window thickness are compared with similar results obtained on gold, nickel, and ion-implanted boron contacts