Simulation And Calculation Of Neutron Imaging

As a nondestructive testing method,neutron imaging technology is playing an increasingly important role in various industrial fields and scientific research fields.Among them,fast neutron imaging technology has its irreplaceable characteristics because of its strong penetrability effect.Therefore,the research of fast neutron imaging technology is of great significance.However,due to fast neutron imaging system's complexity of the device,the large experimental cost,simulation of fast neutron imaging technology research is very necessary.Based on the deep research of the principle and structure of the fast neutron imaging system,the fast neutron imaging system is modeled by Monte Carlo software MCNP.After deriving the relation between the actual imaging pixel value and the energy deposition in the simulation,the energy deposition of exiting neutron on the BC400 plastic scintillator plate was calculated by using MCNP,and using the results obtained by C ++ program and Matlab software the simulation images are drawn,and the obtained simulation images are basically the same in space structure as the sample model to be tested.It shows that the simulation of MCNP software for fast neutron imaging system is basically accurate and can be used for other calculation of fast neutron imaging system.In the following,we optimize the collimator part of the fast neutron imaging system.First,the collimator's material and structure are designed and calculated according to the sheilding requirements of the collimator.The collimator structure and the thickness of each layer are determined.Then the collimators of collimating channels of different shapes are simulated according to the uniformity of the neutron flux distribution at the outlet of the collimator.The inverted biconic collimation tunnel is determined to meet the requirement of fast neutron imaging system.The influence of the three parameters that determine the structure of the inverted double-cone collimator on the outgoing neutron beam of an inverted double-cone collimator is obtained by simulation.The simulation results of the inverted double cone collimator show that a collimator structure with an ideal exiting beam is obtained.