Peak tailing cancellation techniques for digital CR-(RC)n filter

Abstract

The CR-(RC)n filter is used for Semi-Gaussian pulse shaping in analog spectroscopy. A new digital CR-(RC)n filter is presented based on the recursive models of the CR filter and RC filter. The spectroscopic signal reconstruction technique is proposed. This technique is applied to digital exponential decay signals obtained by the digitization of analog signals that represent the combined response of a FAST-SDD detector and the associated front-end circuit. Compared with the direct application of the digital CR-(RC)n filter, the technique eliminates the undershoot of the Semi-Gaussian pulse which is the primary cause of the low-energy peak tailing. And, the digital pole-zero cancellation filter follows digital CR-(RC)n filter to reduce the long tail of the shaped Semi-Gaussian pulse which leads to the high-energy peak tailing. Experimental results based on XRF signals of manganese sample show that the proposed techniques can cancel peak tailing due to the shaped Semi-Gaussian pulse improving FWTM/FWHM ratio and throughput capability.