Application Research For Optimization Design Of GM Detector With Mento Carlo Method

Based on Mento Carlo method, MCNP, a software for particle simulation, is used to do some optimization design researchs for nuclear radiation monitor,and the purpose is to improve the level and efficiency of engineering design of nuclear radiation monitor. According to the content, the paper have two parts in the first part,Mento Carlo method and its development situation is simply introduced first;then a PC cluster solution for MCNP parallel computation based on Windows system is discussed in detail,mainly concern about hardwares construction and softwares configuration,and a efficient and flexible cluster operating code package written in batch technique is given; at last the cluster is tested for its stability and speedup factor with two instances,one is about optimization design of GM counter,and the other is about nuclear radiation shielding,the test results show that the stability of cluster is very well, there are no any failure occurring after a long time more than 50 hours running,and the efficiency of unit core of CPU is also high enough,the average value is more than 90%,and maximum value can reach 98%. The cluster's performance can satisfy the requirement of rapid engineering design. In the second part,firstly the working mechanism and the current situation of GM counter is simply presented,as following,the research and design model with Mento Carlo method is introduced,secondly,based on the particular parameters of one type GM counter,combined with the reference and calibration source such as 137Cs plane source,a input text file read by MCNP is written,and run on the cluster to do the simulating calculation. The basic process is discribed as follows,according to the operating mechanism of GM counter,the deposition of particles energy in the sensitive regions of detector will be simulated and record,then the energy response curve will be get and drawn,it is compared with the response curve gotten in the experiment with the same input parameters,and the correctness and reliability of current research with MCNP is established and verified,it shows that many experiment steps in the middle engineering design can be replace by Mento Carlo method and associated software. At last,based on the simulation of bare GM tube,a lot of simulating calculations are done to get several optimization results according to the energy response curve by adding cladding,changing cladding materials,shape and thickness,a series of conclusions are also listed at the end.