The Simulation Of Neutron Collimation Device Of Drugs And Explosives Detection System With Computer

Non-intrusive inspection technology of drugs and explosives detection is getting more and more attention of countries all over the world. This technology has been a vital tool in combating terrorism and banning drugs. Because neutron detection method can analyze the elements of goods being detecting and neutron has strong penetrating force, it has a lot of predominance to use neutron technology in drugs and explosives detection. Especially with the development of the PFTNA technology, it makes more efficient the technology of quantitative analysis of the elements such as C, H, O, N etc. in drugs and explosives.It is helpful to design a suitable neutron collimation device of drugs and explosives detection system which use neutron generators as neutron sources. The device can not only reduce the effect of objects around but also benefit the radiation defence of the whole system.Monte Carlo Method can realistically describe the random events and simulate the experiment courses. It is very suitable for the calculation of particle transport problem which has the randomicity. The method has been widely used in the simulation of nuclear experiments include neutron detection. MCNP is a general program to simulate nuclear experiments, which is made by Los Alamos Station Lab in America based the Monte Carlo thoughts.In the article the author used the MCNP 3B program to simulate and calculate the neutron collimation device of drugs and explosives detection system. The results show that the tungsten and the polythene with 8%~10% B4C by weight are good moderator material of 14MeV neutrons and variety rules of 14MeV neutrons along and apeak the axis are uniform between the column model and the sphere model, but the column model is superior to the sphere model in neutron counts at collimation hole and the relatively intensity of neutrons.