医院中子照射器治疗束中子参数测量

Measurement of Neutron Parameters in the Treatment Beam of In-Hospital Neutron Irradiator

为了对医院中子照射器的设计指标进行验证,利用金箔活化法测量了其治疗束出口处中子注量率,并采用金刚石探测单元的扫描装置测量治疗束出口处热中子、超热中子、快中子和γ射线注量率的径向分布。结果显示,在30 kW满功率运行时,热中子束及超热中子束出口中心处,热中子注量率分别为1.75×10^(9)cm^(-2)·s^(-1)和6.57×10^(7)cm^(-2)·s^(-1),超热中子注量率分别为1.41×10^(7)cm^(-2)·s^(-1)和3.14×10^(8)cm^(-2)·s^(-1);治疗束主要分布在束流孔径内,靠近束流边缘会出现指数级下降现象。该测量结果为医院中子照射器开展后续相关测试及实验提供了参数支持。

In order to verify the design specifications of in-hospital neutron irradiator(IHNI),the neutron fluence rates at the exit of its thermal and epithermal neutron beams were measured by using the method of cadmium difference.The radial distribution of the different components of the treatment beam exit was measured using a scanning device with a diamond detection unit.The results show that the thermal neutron fluence rates are 1.75×10^(9) cm^(-2)·s^(-1) and 6.57×10^(7) cm^(-2)·s^(-1) at the center of the thermal and epithermal neutron beams,respectively,and the epithermal neutron fluence rates are 1.41×10^(7) cm^(-2)·s^(-1) and 3.14×10^(8) cm^(-2)·s^(-1) at 30 kW full power operation;The vast majority of the treatment beam components are distributed within the beam aperture,with an exponential drop-off near the beam edges.The measurement results provide parameter support for subsequent related testing and experiments of In-Hospital Neutron Irradiators.