Nuclear Techniques ›› 2015, Vol. 38 ›› Issue (10): 100403-100403.doi: 10.11889/j.0253-3219.2015.hjs.38.100403


Study of fission ionization chamber in CSNS flux monitor system

WANG Qi1 BAO Jie1 HOU Long1 RUAN Xichao1 SU Xiaobin1 JING Hantao2 LI Qiang2   

  1. 1(Key Laboratory of Nuclear Data Measurement and Evaluation Technology, China Institute of Atomic Energy, Beijing 102413, China) 2(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China)
  • Received:2015-01-19 Revised:2015-05-12 Online:2015-10-10 Published:2015-10-14

Abstract: Background: The fission ionization chamber is constituted by 235U and 238U materials as monitor in China Spallation Neutron Source (CSNS) reverse angle. Purpose: This paper mainly introduces the whole system time precision influence on the energy resolution and the actual measurement corrections. Method: The flux energy spectrum is measured accurately using n-TOF method. Results: The time resolution which is caused by energy resolution is proportional to 3/2 power energy, and the correction is induced less than 0.1% due to differences of the standard cross section energy. Conclusion: The experimental results show that the design of the ionization chamber can meet the requirements of CSNS neutron flux measurements.

Key words: Time resolution, Neutron spectrum, Fission ionization chamber