The measurement of DD neutron yield by activation is presented. This method is based on the inelastic scattering reaction of 115In with DD neutron, and the activated y spectrum is counted by HPGe detector. The relation between the counts of detected y rays and the neutron yield is analyzed. The optimal thickness of sample is given by Monte Carlo simulation, which is 1 cm. The entire counting system has been calibrated on the K-400 accelerator. The result shows that the DD neutron measurement by indium activation can be used in the ICF experiment when the neutron yield is above 2×109. The total error of the system is below 10% in this condition. The total error will reduce when the neutron yield is larger.%提出了活化法测量DD中子产额的实验方法,该方法可提高DD中子产额测量的精度.方法基于铟同位素115In与DD中子的非弹性散射反应,活化反应释放的γ射线被HPGe探测器记录,根据活化系统标定灵敏度推算出中子产额.分析了探测器记录的活化γ射线数与中子产额间的关系.介绍了一套活化测量的系统设计.通过蒙特卡罗方法模拟了活化样品出射的γ射线数与样品厚度的关系,模拟结果表明:样品厚度取为1cm可兼顾活化效率和测量精度.在加速器上对铟活化样品进行了标定实验,实验结果表明:在聚变中子产额大于2×109的实验中可使用铟活化诊断方法,中子产额测量的相对标准误差在10％以内.随着聚变中子产额的不断提高,铟活化测量中子产额的精度可进一步提高.
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