Simulation research on the characteristics of a minitype neutron reference radiation field

In order to research the characteristics of minitype neutron reference radiation field regulated by ISO 8529 series standards, Monte Carlo simulation method was applied to calculate the ratio of room-scattered neutron response to the direct neutron response, neutron fluence and energy spectra in the radiation field. Firstly, the characteristics of the field were investigated from the four physical factors as shielding materials, field sizes, shielding thicknesses and borated polyethylene with different boron contents. Secondly, the response of sphere instrument with different diameters in the field and the influence of instrument on the field were analyzed. The results showed that minitype neutron reference radiation field with a size of 2 m x 2 m x 2 m, a shielding material of 5 % borated polyethylene and a shielding thickness of 10 cm was expected to be used for the calibration of neutron measuring instrument.