涂硼电离室中子灵敏度计算与验证

Calculation and Verification of Neutron Sensitivity for Boron-Coated Ionization Chamber

假设α粒子或Li离子探测器效率相同时,α粒子或Li离子对探测器输出电流相同,计算了10B丰度为90%,硼面密度为0.8mg/cm2,涂硼面积为2760cm2,电离室中子灵敏度为5.25×10-13A/(n·cm-2·s-1)。采用10B丰度为90%的硼粉制作了面密度为0.8mg/cm2的电极管,将其组装为电离室样件,工作气体介质为P10气体;在线性中子源上测试了工作气体压力为0.025MPa^0.3MPa,电离室样件的中子灵敏度,结果表明:气体压力达到0.16MPa时,电离室样件的输出电流饱和,硼层中出射粒子的能量完全沉积到工作气体中,此时的中子灵敏度为4.01×10-13A/(n·cm-2·s-1),试验结果与理论结果偏差约为25%左右。

When the detection of efficiency of particles or Li ions is the same,the ionization output current of particles or Li ions is the same.The abundance of 10B is 90%,the surface density is 0.8mg/cm2,the boron-coated area is 2760 cm2,and the neutron sensitivity of the ionization chamber is 5.25×10-13A/(n·cm-2·s-1).An electrode tube with boron-coated surface density of 0.8mg/cm2 was prepared with 10B Abundance of 90%boron powder and assembled into an ionization chamber sample.The working gas medium of the sample was P10 gas.The neutron sensitivity of the sample in the ionization chamber was measured at a linear neutron source with the gas pressure of 0.025MPa^0.3MPa.The results show that when the gas pressure reaches 0.16MPa,the output current of the sample in the ionization chamber is saturated,and the energy of the particles emitted from the boron layer is completely deposited into the working gas.At this time,the neutron sensitivity of the ionization chamber is 4.01×10-13A/(n·cm-2·s-1).The deviation between the experimental results and the theoretical calculation is about 25%.