Nuclear Techniques ›› 2017, Vol. 40 ›› Issue (6): 60403-060403.doi: 10.11889/j.0253-3219.2017.hjs.40.060403


Digitalization of CR-RCm filter

LIU Yinyu, ZHANG Jinglong, ZHOU Rong, YANG Chaowen   

  1. College of Physical Science and Technology, Key Laboratory of Radiation Physics and Technology, Ministry of Education, Sichuan University, Chengdu 610064, China
  • Received:2017-02-17 Revised:2017-03-14 Online:2017-06-10 Published:2017-06-06
  • About author:10.11889/j.0253-3219.2017.hjs.40.060403
  • Supported by:
    Supported by National Natural Science Foundation of China (No.11205108, No.11475121), Excellent Youth Fund of Sichuan University (No.2016SCU04A13)

Abstract: Backgrounds:The CR-RCm filter is a classic and widely used filter for nuclear analog signal processing circuit. It possesses the advantages of superior performance and simple implementation.Purpose:This study aims to digitize CR-RCm filter and discuss its performance with different RC and m parameters. Methods:Based on the linear differential equation with constant coefficients of analog RC (CR) filter's input and output voltage, recursive formulas of the digitized CR high-pass filter and RC low-pass filter were derived, and system transfer function of digitalization CR-RCm filter was further deduced. After analysis of the characteristics of digitalized CR-RCm filter in time-domain and frequency-domain, both the energy spectra and the resolution of full energy peak before and after the CR-RCm filter were experimental tested. Results:The digitalized nuclear pulse signal was shaped as Gaussian waveform by CR-RCm filter. The energy resolution of 137Cs spectrum was improved 1% through CR-RCm filter and could further enhanced by adjusting RC and m parameters.Conclusion:Digitalization CR-RCm filter could be used to reform pulse signal to increase the signal-to-noise (SNR), hence improve spectrum resolution of nuclear signal.

Key words: Digitize, RC filter, CR-RCm shaping, Gauss shaping, Energy resolution

CLC Number: 

  • TL82