摘要
本文利用经由低能窄谱X射线刻度过的商用大体积球形空腔电离室,开展了低能光子^(125)I近距离治疗源参考空气比释动能的测量方法研究。通过运用蒙特卡罗洛模拟的方法,得到6711型放射源的能谱及发射光子的平均能量,同时也计算出空间散射修正、非均匀性修正、空气衰减修正等多项修正因子。采用插值法得到了球形空腔电离室的刻度因子,并设计了专用的测量支架,最终实现了低能光子^(125)I近距离治疗源参考空气比释动能率的测量,其不确定度为3.8%(k=2),测量结果与溯源至加拿大NRC的井型电离室偏差优于0.29%,具备了低能光子近距离治疗源参考空气比释动能率量值传递的能力。
The research team conducted a study on the measurement method of reference air kerma for low-energy photon ^(125)I brachytherapy source using a commercial large-volume spherical cavity ionization chamber calibrated with low-energy narrow-band X-rays.Through the use of Monte Carlo simulation,the energy spectrum and average energy of emitted photons for the 6711 type radioactive source produced by Beijing Zhibo Bio-Tech Co.,Ltd.were obtained,and several correction factors such as spatial scattering correction,non-uniformity correction,and air attenuation correction were also calculated.The team also used interpolation method to obtain the calibration factor of the spherical cavity ionization chamber and designed a dedicated measurement bracket.Finally,we achieved the measurement of reference air kerma rate for low-energy photon ^(125)I brachytherapy source with an uncertainty of 3.8%(k=2),and the measurement results were in good agreement with the well-type ionization chamber traceable to the Canadian NRC,with a deviation of less than 0.29%.
作者
王继
韩金鹏
侯晓飞
王培玮
王坤
吴金杰
WANG Ji;HAN Jinpeng;HOU Xiaofei;WANG Peiwei;WANG Kun;WU Jinjie;AN Xingtao(National Institute of Metrology,Beijing 100029,China;Hebei University of Science and Technology,Shijiazhuang 050018 China;Beijing Zhibo Bio-Tech Co.,Ltd,Beijing 102502,China)
出处
《核电子学与探测技术》
CAS
北大核心
2024年第6期1083-1090,共8页
Nuclear Electronics & Detection Technology
基金
国家重点研发计划:质子与近距离放疗剂量绝对测量与量值溯源技术研究(2023YFF0613503)
中国计量科学研究院仪器共享项目:铱-192伽马射线参考辐射装置共享优化(YOGX2306)。
