Nuclear Techniques ›› 2015, Vol. 38 ›› Issue (1): 10401-010401.doi: 10.11889/j.0253-3219.2015.hjs.38.010401


Simulation study on digital processing of fission chamber output signal

YUAN Chao1,2,3 LI Yongping1,3 HUANG Yuefeng1,3   

  1. 1(Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Jiading Campus, Shanghai 201800, China) 2(University of Chinese Academy of Sciences, Beijing 100049, China) 3(Key Laboratory of Nuclear Radiation and Nuclear Energy Technology, Chinese Academy of Sciences, Shanghai 201800, China)
  • Received:2014-09-23 Revised:2014-10-16 Online:2015-01-10 Published:2015-01-07

Abstract: Background: Neutron flux density is an important parameter related to nuclear power of the reactor. Digitized processing of neutron flux density in a wide measurement range of fission chamber detector has more advantages than the traditional analog circuits. Purpose: The aim is to improve the accuracy of neutron counting in the pulse mode, as well as mean square value calculation in the Campbell mode. Methods: The waveform of the output signal of fission chamber with various electronic noise was simulated, and then a trapezoidal shape filtering and digital adaptive filtering were employed to deal with digitized waveform signal of fission chamber in both low neutron flux density (pulse mode) and high neutron flux density (Campbell mode) circumstances. Results: By using these two methods, the accuracy of both the pulse counting and mean square value calculation was improved. Conclusion: Trapezoidal shape filtering and digital adaptive filtering can be applied to process digitized fission chamber output signal to achieve precise measurement of the neutron flux density in a wide range.

Key words: Fission chamber, Wide range, Digital