用MCNPx程序计算宽能谱中子雷姆仪的响应曲线

利用MCNPx程序计算了宽能谱中子雷姆仪的响应曲线。计算表明，增加铅层对低能中子的响应没有明显的影响，但在高能区(几百MeV以上)宽能谱中子雷姆仪的响应与铅层的厚度有关。铅层厚度为0．6cm时响应比普通雷姆仪提高约3倍，当铅层厚度增加到1．2cm时响应高约5倍。虽然计算结果与ICRP建议书中的H^*(10)曲线相比还有一定的差别，但改变慢化体的结构对提高高能中子的探测效率是有明显效果的。The responses of two extended neutron rein counters as function of neutron energy was ca1cuated Monte Carlo code，MCNPx，was applied in the calculations．Isotropic neutron incidence was employed．The results show that the neutron response is independent on thickness of lead 1aver at low energies，and it is clearly increased with thickness of lead layer at high energies．Although tt1e shape of the response curve does not completely agree with the H (10) curve in ICRP 74 report ，the resuhs obtained give good bases for the practical use of the new instrument in high—energy neutron fields

MCNPx Calculation of Neutron Response for an Extended Range Neutron Rem Meter

The responses of two extended neutron rem counters as function of neutron energy was calculated. Monte Carlo code, MCNPx, was applied in the calculations. Isotropic neutron incidence was employed. The results show that the neutron response is independent on thickness of lead layer at low energies, and it is clearly increased with thickness of lead layer at high energies. Although the shape of the response curve does not completely agree with the H~*(10) curve in ICRP 74 report, the results obtained give good bases for the practical use of the new instrument in high-energy neutron fields.