Influences of fusion neutrons on Compton suppressed γ-spectrum analyses at the HL-2A tokamak

Jie Zhang; Yipo Zhang; Jinwei Yang; Guoliang Yuan; Gang Li; Xianying Song; Xu Li; Zhongbing Shi; Yi Liu

doi:10.1016/j.apradiso.2020.109387

Influences of fusion neutrons on Compton suppressed γ-spectrum analyses at the HL-2A tokamak

Appl Radiat Isot. 2020 Dec:166:109387. doi: 10.1016/j.apradiso.2020.109387. Epub 2020 Aug 19.

Authors

Jie Zhang¹, Yipo Zhang², Jinwei Yang³, Guoliang Yuan³, Gang Li⁴, Xianying Song³, Xu Li³, Zhongbing Shi³, Yi Liu³

Affiliations

¹ Southwestern Institute of Physics, PO Box 432, Chengdu, 610041, China. Electronic address: zhangjie@swip.ac.cn.
² Southwestern Institute of Physics, PO Box 432, Chengdu, 610041, China. Electronic address: zhangyp@swip.ac.cn.
³ Southwestern Institute of Physics, PO Box 432, Chengdu, 610041, China.
⁴ Science and Technology on Reactor System Design Technology Laboratory, Nuclear Power Institute of China, Chengdu, 610213, China.

PMID: 32877860
DOI: 10.1016/j.apradiso.2020.109387

Abstract

The newly-built Compton suppression system at the HL-2A tokamak works in a harsh fusion neutron field especially when the second neutral beam injection system is put into application. The present paper performed Geant4 simulations to study the influences of fusion neutrons on Compton suppressed γ-spectrum analyses. The simulation data show that the influence of fusion neutrons on suppressed γ-spectrum shape is limited, while the influence on detection efficiencies is considerable. Consequently, the changes of detection efficiencies caused by the coexisting neutrons must be taken into account in the subsequent γ-spectrum analyses. Hence, the empirical formulas of γ-ray detection efficiencies of the Compton suppression system, which had considered the influences of fusion neutrons, were put forward and then applied to unfold the experimental γ-spectra. This work lays a superior foundation for the further analyses of the Compton suppressed γ-spectra at the HL-2A tokamak.

Keywords: Compton suppression system; Fusion neutrons; Gamma spectrum analyses; Geant4 simulation; γ-ray diagnostic.