Software based digital signal processing and spectrum deconvolution in X-ray spectroscopy

Approaches for software based digital signal processing and numerical decon volution of measured signals which overcome limitations of state-of-the-art systems are described. The basic technical equipment for digital signal pr ocessing consists of an energy resolving detector with a preamplifier follo wed by a fast sampling analogue-to-digital converter (ADC). The main idea i s the numerical decomposition of the measured signal into contributions cau sed by single photon absorption using standard pulses. The latter can be ob tained by measurements under definite conditions. The maximum pulse rate is then limited only by the ratio of sampling time to the time between two pu lses which should be attributed to single events. Thus pulse overlaps do no t require pulse rejection. At sampling rates of 10(8) samples per second th eoretically a comparable photon rate can be detected at throughputs of 100% . Beyond that it is outlined that in a comparable manner a numerical deconvol ution of measured energy spectra (statistic distribution functions of singl e events) into combinations of standard spectra, which can likewise be dete rmined by measurement, offers outstanding possibilities, too. On the one ha nd the energy resolution attainable for individual events for a given detec tor can be improved drastically by the statistical treatment of spectra. On the other hand an energy resolving work principle becomes possible for cer tain detectors, which do not permit this conventionally due to their poor s ignal to noise ratio.