四川大学学报（自然科学版）2025，Vol.62Issue(2)：451-457,7.DOI:10.19907/j.0490-6756.240121
用于聚变装置的溴化镧探测器在0.1～11 MeV γ能区的能量刻度和效率刻度研究
Study of the energy calibration and efficiency calibration of a lanthanum bromide detector for fusion devices in the 0.1～11 MeV γ energy region
摘要
Abstract
Tokomak confinement plasma generates high-energy hard X-rays during plasma discruption events.Detection of these high-energy hard X-rays provides critical insights into confinement dynamics during breakdown in fusion devices.We have developed a lanthanum bromide detector system to meet the require-ments for high-energy hard X-rays diagnostics in the HL-3 device at the Southwest Institute of Physics of the Nuclear Industry.The crystal size of the developed lanthanum bromide detector system is φ76 mm×76 mm,and the performance test of the developed lanthanum bromide detector was carried out:The background count rate of the detector in the shield composed of lead,cadmium,and copper plexiglass is 455 cps,and the 32 keV and 788 keV γ-rays emitted by decaying radionuclides 138La and 40K decaying γ-rays contained in the crystal of lanthanum bromide and the photomultiplier material were analyzed.1461 keV γ-rays from the 40K decay contained in the tube material,and the alpha decay of the naturally occurring radioactive element 227Ac and its daughter contained in the lanthanum bromide crystals also contribute to the background energy spec-trum;The energy resolution of 662 keV γ-rays obtained by using the standard source 137Cs is about 3%;The energy calibration of the gamma energy region below 2 MeV has been carried out by using the standard sources 137Cs and 152Eu.The energy calibration and the efficiency calibration of full energy peak detection were carried out in the gamma energy region below 2 MeV;In the γ-energy region above 2 MeV,due to the lack of standard gamma sources,high energy γ-rays produced by thermal neutron activation of light elements such as 14N in the 2～11 MeV energy region were used to complete the energy calibration and the efficiency calibra-tion in this energy region.The neutron source used in the experiments was the Am-Be neutron source with an average energy of 4.5 MeV of emitted neutrons,paraffin wax was used as the neutron moderator,and urea(CH4N2O)with a high nitrogen content was used as the nitrogen sample,and in order to achieve the best neu-tron moderating effect to increase the intensity of the required high-energy gamma rays emitted,MCNP was used to optimally select the dimensions of the moderators.The self-absorption of γ-rays of different energies was also calculated in the urea sample.The experimental results show that the developed lanthanum bromide detector has good energy linearity in the 0.1～11 MeV γ-energy region,the typical error of the detection effi-ciency of the full energy peaks obtained from the standard source scale is less than 1.89%.MCNP5 was used to simulate the full energy peak detection efficiency of the developed lanthanum bromide detector.Based on the dimensional structure of the lanthanum bromide probe provided by the manufacturer,a model of the lan-thanum bromide probe was established to simulate the full energy peak detection efficiency of the γ-rays with energies ranging from 0.1～10.829 MeV,and a comparative analysis was carried out with the results of the experimental measurements.关键词
溴化镧探测器/效率刻度/能量刻度/蒙特卡罗Key words
Lanthanum bromide detector/Efficiency calibration/Energy calibration/Monte Carlo分类
能源科技引用本文复制引用
叶茜,罗小兵,祝家俊,鄢文轩,罗冬梅..用于聚变装置的溴化镧探测器在0.1～11 MeV γ能区的能量刻度和效率刻度研究[J].四川大学学报（自然科学版）,2025,62(2):451-457,7.基金项目
国家磁约束核聚变能发展研究专项(2019YFE03010003) （2019YFE03010003）
