Research of Material Irradiation Fine Neutron Flux Spectrum in HFETR

The paper calculated and compared the fine neutron flux spectrum of the material at the typical irradiation channels of HFETR using MCNP code,including axial and radial distribution of neutron fluxes,and the 172-group neutron energy spectrum.It indicates that the distributions and characteristics of neutron energy spectrum in different channels filled with the same material,and in the same channel filled with different materials are almost identical,that is,the neutron energy spectrum with high energy is similar to fission neutron spectrum,the spectrums with middle energy and low energy are similar to Fermi spectrum distribution and Maxwell distribution separately.