Research And Implementation Of Digital Nnclear Spectrum Measurement System

Nuclear spectrum measurement technology is a kind of nuclear analysis method which is based on nuclear signal spectrum extraction, involving many technical fields such as nuclear electronic technology and detection technology, sensing technology and computer technology. Traditional nuclear spectrum measurement system used hardware circuit to realize function modules, with poor flexibility and performance. The rapid development of high-speed ADC and digital signal processors promoted its digital realization. So digital nuclear spectrum measurement system has superior behavior in performance, structure, function reconstruction and it has important academic significance and application value.This paper discussed the characteristics of nuclear pulse signal, summarized the structure of digital nuclear spectrum measurement system, analyzed the major factors affecting system performance and gave a digital method to weaken these impacts; Secondly, did a research on existing processing algorithm of baseline estimation, filtering & shaping and amplitude extraction. Through the advantages and disadvantages comparison, sage-husa-based adaptive Kalman filtering algorithm was selected for baseline estimation, function-convolution-based trapezoidal shaping algorithm, pulse-integration-based amplitude extraction algorithm were selected for corresponding process, whose feasibility analysis were all carried out in Matlab simulation. Thirdly, the digital nuclear spectrum measurement system was completed ultimately by developing the digital hardware platform and doing the function design and verification of signal acquisition, baseline estimation, trapezoidal shape, channels storage and communication. To realize system performance testing, developed spectrum analysis software with MFC application framework, which included functions of spectral data smoothing, resolution calculation and net area calculation.The testing results showed this system could achieve the expected parameter index, with high pulse counting rate and energy resolution. Compared with the traditional ones, its performance was improved significantly.