A Comprehensive Performance Study of Digital Pulse Processors in Si-PIN Detector-Based XRF Systems

The digital pulse processor (DPP) serves as the core of X-ray fluorescence spectroscopy (XRF) systems, where its performance dictates the quality of energy spectra and overall analytical precision. Traditional analog multichannel analyzers (MCA) are constrained by hardware architecture, leading to significant pulse pile-up and dead-time effects that degrade energy resolution. While digital signal processing offers a robust alternative, domestically developed DPP in China are currently in the early stages compared to established international products, necessitating rigorous validation of their performance and engineering utility. In this work, the design architecture and characteristics of the domestic DPP_NCP1 are presented, and its performance is evaluated within an XRF experimental system coupled with a Si-PIN detector. Comparative benchmarks are conducted against a domestic analog multichannel analyzer (NUMCA) and a commercial digital pulse processor (DP5X). Experimental results indicate that the energy spectra acquired by the DPP_NCP1 exhibit sharp primary peaks and distinct secondary peaks, effectively eliminating the tailing phenomena inherent in MCA systems. At operating temperatures of 250 K and 255 K, the energy resolution of the DPP_NCP1 for Mn (5.9 keV) and Ag (22.1 keV) shows significant improvements over the NUMCA, specifically enhancing the Mn resolution by approximately 50% and that of Ag by 60 eV. Although the energy resolution of the DPP_NCP1 is marginally higher than that of the DP5X (by 3–10 eV), its relative standard deviation (RSD < 0.46%) is notably lower, demonstrating superior measurement consistency. Furthermore, the DPP_NCP1 maintains high peak stability with a shift of less than one channel under constant temperature; under thermal fluctuations (250–255 K), the drift characteristics for Mn and Ag are highly consistent with those of the DP5X. These findings confirm that the DPP_NCP1, in conjunction with Si-PIN detectors, delivers excellent performance in energy resolution, signal stability, and signal-to-noise ratio, underscoring its significant potential for reliable engineering applications. The BRIEF REPORT is available for this paper at http://www.ykcs.ac.cn/en/article/doi/10.15898/j.ykcs.202506060150.