中子管非中子产物性质

Properties of non-DT-neutron products in neutron tubes

采用两只经过标定的ST401闪烁探测器,测量了脉冲中子管的中子产额,在其中一只探测器前端增加铅板屏蔽,1cm的铅屏蔽使探测器输出减少了18.20%,在加速器中子源上进行的类似实验表明,0.5cm的铅使探测器的输出减少了2.90%。对两个中子源上测量的情况进行了蒙特卡罗模拟,加速器实验与模拟符合较好,脉冲中子管实验差别较大。对实验和模拟的情况进行了分析,结果表明:中子管除产生中子外,还会产生数量较多的轫致辐射X射线,这些X射线对准确测量中子管中子产额将造成不良影响。

By using two calibrated ST401 scintillation detectors, the neutron yield of a pulse neutron tube was measured, and by adding a Pb shield before one detector, the influence of the Pb shield on neutron flux was determined. The 1 cm thick Pb shield decreases the neutron flux by 18.20%. The influence of the Pb shield on accelerator neutron sources was determined the same way. The 0.5 cm thick Pb shield decreases the neutron flux by 2. 90%. The measurements of two neutron sources were simulated by Monte Carlo. Compared with the neutron tube experiment, the accelerator experiment results agree with the simula- tion better. The theoretical analysis shows that neutron tubes can generate much bremsstrahlung X rays, which may have harmful impact on the measurement of neutron tube yields.