Simulation of gamma ray deep penetration through iron based on grid weight window iteration

To improve the efficiency of gamma ray deep penetration shielding calculation, this paper analyzed the influence of gamma ray energies, shield thickness, shielding materials and number of simulated particles on the transport calculation of gamma ray deep penetration, and proposed a Monte Carlo simulation method for gamma ray deep penetration shielding by iterative calculation based on the combination of grid weight window and material density gradually approaching true density. The simulation results show that, by using the iterative calculation method based on grid weight window in MCNP program, it can be realized that gradual transition from non deep penetration shielding simulation to deep penetration shielding simulation. The method can effectively solve the problem of gamma ray deep penetration calculation, and it can make the statistical error of the transmission coefficient of gamma ray penetrating the iron shield with a thickness of 60 times the mean free path of gamma ray less than 5%, which can meet the demand of gamma ray deep penetration simulation.