摘要
计算了不锈钢、铅和钨材料对不同能量硬X射线的衰减规律,根据计算结果设计了东方超环(EAST)超导托卡马克硬X射线诊断系统探测器的屏蔽准直体;详细介绍了EAST上硬X射线诊断系统,利用^(22)Na放射源对诊断系统进行了台面实验测试,通过放射源的γ射线能谱研究了不锈钢和钨材料对γ射线的衰减规律,拟合计算了衰减系数;同时将实验结果和理论计算结果进行了比较,考虑到实验误差的影响,实验结果和理论计算结果是一致的。通过研究γ射线能谱,对不锈钢和钨材料对X射线、γ射线诊断产生的影响进行了评估。研究结果发现:不锈钢对低能的X射线和γ射线诊断的影响比较严重,而对高能硬X射线以及高能γ射线诊断的影响在一定程度上是可以忽略的,但是要避免探测器的准直孔前方有钨和铅等高Z材料,以减小对诊断数据的影响。
Attenuation coefficients ofγ-rays in stainless steel,lead,and tungsten were calculated theoretically.According to the theoretical calculations,cylindrical lead shielding and a collimator were designed for a high-energy hard X-ray spectrum diagnostic system in the Experimental Advanced Superconducting Tokamak(EAST).The hard X-ray diagnostic system of EAST was introduced in detail,and the diagnostic system was tested through table experiments with radioactive^(22)Na sources.Attenuation coefficients ofγrays in stainless steel and tungsten were also obtained by fittingγ-ray radiation spectra.The effect of the stainless steel and tungsten materials on the X-ray andγ-ray diagnostic system was evaluated byγ-ray energy spectra.The attenuation coefficients obtained through the experiments were found to agree well with those calculated theoretically considering the error.The influence of stainless steel on low-energy X-ray orγ-ray diagnostics cannot be ignored,while its influence on high-energy X-ray orγ-ray diagnostics can be ignored.The influence of tungsten on X-ray orγ-ray diagnostics cannot be ignored.However,high Z materials such as tungsten and lead should be avoided in front of the collimation hole of the detector to reduce the influence on diagnostic data.
作者
卢洪伟
倪志娇
查学军
LU Hongwei;NI Zhijiao;ZHA Xuejun(College of Science,Donghua University,Shanghai 201620,China;People's Republic of China and Member of Magnetic Confinement Fusion Research Center(Donghua University),Ministry of Education,Shanghai 201620,China)
出处
《辐射研究与辐射工艺学报》
CAS
CSCD
2021年第4期84-90,共7页
Journal of Radiation Research and Radiation Processing
基金
东华大学中央高校基本科研业务费专项资金(16D110918、17D110910、19D110914、20D110910)
国家自然科学基金(11205029)资助。
关键词
托卡马克
硬X射线
钨
不锈钢
衰减系数
Tokamak
Hard X-ray
Tungsten
Stainless steel
Attenuation coefficient