Research on the Development and Performance Regulation Mechanism of Silicon Drift Detectors Based on Domestic Chips

Silicon drift detectors (SDD) hold significant application value in high-precision detection tasks due to their inherent advantages of high energy resolution, low noise, and rapid response. Addressing the performance bottlenecks of domestic SDD concerning leakage current control, readout electronics integration, and high-throughput signal processing, this study focuses on the independent research and development of core detection devices. Herein, we report for the first time the development and systematic parameter characterization of PA150, an SDD based on a domestically produced chip. To comprehensively characterize the key physical specifications of this newly developed chip, an X-ray fluorescence (XRF) testing system was constructed to conduct an in-depth evaluation of its comprehensive performance, including energy resolution, count-rate linear response, and multi-element identification capabilities. The experiment investigated the synergistic modulation mechanism of operating temperature and peaking time—the signal shaping time constant, which determines the balance between noise filtering bandwidth and pulse pile-up probability—on detector performance. The results indicate that the PA150 achieves an energy resolution of 143 eV at 5.9 keV, representing an improvement of approximately 25% compared to the PA200 Si-PIN detector independently developed by our institute. Furthermore, physical mechanism analysis reveals that lowering the operating temperature effectively suppresses the parallel noise and thermal noise induced by the detector's leakage current. Meanwhile, adjusting the peaking time achieves a minimum-value balance between series noise (which is inversely proportional to time) and parallel noise (which is directly proportional to time). Based on the optimal parameter combination determined by this mechanism (–23℃ coupled with a 4–5 μs peaking time), the detector’s energy resolution is further improved to approximately 140 eV, achieving a high count rate of 42.99 kcps while maintaining excellent resolving capabilities. When the peaking time is reduced to 1 μs, the count rate reaches 51.39 kcps. These performance metrics are comparable to those of international commercial SDD, demonstrating exceptional characteristic peak separation capabilities in XRF applications. The independent development of this SDD effectively resolves the reliance on imported core detectors for the rapid screening of complex matrix samples (such as heavy metals in soil) by domestic XRF equipment, providing an indigenous technological solution for geological, environmental, and industrial online inspections.