Determination of α factor of epithermal neutron flux in Dalat reactor, Vietnam, based on neutron spectrum calculated using MCNP code.

The α-factor is a measure of the epithermal neutron flux deviation from the ideal distribution 1/ E, where E is neutron energy. It defends on the position of the irradiation channel in reactor. A determination method of the α-factors in irradiation channels of Dalat reactor is presented by fitting the epithermal neutron spectrum obtained from the calculation using MCNP code. The fitting α-values were compared to those by experiment used the “Cd-ratio” method with monitors 197Au–94Zr and 197Au–64Zn. It shows that the α-values calculated from neutron spectra agree well with experimental ones. The difference between both data is about 6%. [ABSTRACT FROM AUTHOR]