一种改进型源倍增法的模拟研究与验证

Simulation study and validation of improved amplified source method

针对源倍增法测量次临界度受到基波份额变化以及通量畸变影响的问题,有文献提出使用环形"集总"探测器布置和"刻度曲线"来改善其测量结果的方法。为了验证该方法的实用性,用超级蒙特卡罗核模拟软件系统SuperMC与混合评价数据库HENDL,以日本京都大学KUCA铅基实验装置为对象,展开了模拟研究。研究结果表明:该改进方法在KUCA实验装置上是适用的,说明此改进方法具有较好的工程应用潜力。模拟结果表明,使用KUCA装置中现有的六个裂变室进行"集总"探测可以给出相对准确的"测量"次临界度,但为了使测量结果更加准确,在未来实验中,可以在堆芯外围布置更多对称的探测器进行"集总"探测。

Amplified Source Method（ASM）is based on point kinetics model.While used in Accelerator Driven System（ADS）with deep subcriticality and strong external source,its result is affected by the external source effect,the fundamental flux effect and the spatial effect seriously.In order to solve this problem,an annular detector positioning method with calibration has been given.In order to test the practicality of this method,further study is performed against the Kyoto University Critical Assembly by Super Monte Carlo Program for Nuclear and Radiation Simulation（SuperMC）with the HENDL database.Numerical results demonstrate that the proposed method works well for the problem and the six fission chambers in the assembly can give a good measurement result.And more detectors arranged on the fringes of the core are needed in the upcoming experiments to get more accurate measurement results.