Comparison of the SAND-II and LOUHI Computer Programs in Unfolding Neutron Flux Density Spectra

Three different problems are selected for the comparison of results obtained by two different neutron flux density spectrum unfolding codes, LOUHI and SAND-II. In the first two problems, a light-water-reactor-type spectrum is considered. For both problems the same input spectrum, the same reaction rates, and the same neutron cross-section data library (ENDF/B-IV) is used. The third problem deals with the betatron-associated neutron flux density spectrum using LOUHI and SAND-II codes in the same way. This technique proved to be very useful in finding in a very practical way the problematic reaction rates, like ²⁷Al(n, α)²⁴Na, ⁴⁸Ti(n, p)⁴⁸Sc, ¹¹⁵In(n, n)^115mIn, ¹²⁷I(n, 2n)¹²⁶I, and ²³²Th(n, f), in neutron spectrum unfolding.