ADVANCED EXPERIMENTAL APPLICATION OF A DIGITAL SIGNAL PROCESSOR IN HIGH-RESOLUTION X-RAY SPECTROSCOPY

''Optimum'' digital filtering of the digitized pulses obtained from a radiation detector had been shown to improve the energy resolution wit h respect to suboptimum analog processing [Rev. Sci. Instrum. 66, 975 (1995)]. This note shows that the improvement does not vanish in very high resolution systems, as it depends on the kind and relative amount of the noises present and not on their absolute value. Using one of t he best available silicon detectors, the electronic noise has again be en towered by 18% from 9.6 to 7.9 electrons rms. (C) 1995 American Ins titute of Physics.