Application of pole-zero cancellation circuit in nuclear signal filtering and shaping algorithm

• 作者: Huai-Ping Wang Jian-Bin Zhou Xiao-Ping Ouyang Xian-Guo Tuo Xu Hong Yi Liu Jie Yu You-Xian Jin
• 来源期刊: 核技术（英文版）
• 年，卷（期）: 2021,（8）
• 所属期刊栏目: NUCLEAR ELECTRONICS AND INSTRUMENTATION
• 页码范围: 85-94
• 页数: 10页
• 语种: 英文

摘要

In radiation measurement and digital nuclear spectrum systems,traditional nuclear signal processing circuits in nuclear electronics have been gradually replaced by digital algorithm modules with the application of high-performance programmable hardware logic devices(such as FPGA or DSP).Referring to the digital realization method of inverse RC integral circuit systems,the function of the pole-zero cancellation(PZC)circuit was analyzed,a new modified cascade equivalent model of PZC was established,and the time-domain digital PZC(DPZC)recursive algorithm was derived in detail in this study.Two parameters kI and kD are included in the new algorithm,where kI should match the exponential decay time constant of the input signal to realize the pole-zero compensation,while the decay time constant of the output signal can be changed with the adjustable parameter kD(which is larger than the decay time constant of the input signal).Based on the new DPZC algorithm module,two trapezoidal(trian-gular)shaping filters were designed and implemented.The amplitude-frequency characteristics of the output signal of the proposed trapezoidal shaping algorithm and the con-volution trapezoidal shaping algorithm were compared,with fixed peaking time.The results show that the trape-zoidal shaping algorithm based on DPZC can better sup-press high-frequency noise.Finally,based on the NaI(T1)scintillator(ψ75 mm×75 mm)detector and 137Cs source,the effect of the kD value on the energy resolution of the DPZC trapezoidal(triangular)shaping algorithm was studied.The experimental results show that,with an increase in kD,the energy resolution of the system improved and reached the maximum when kD was greater than 10,and the optimal energy resolution of the system was 7.72％.