Neutron capture by heavy isotopes of uranium and neptunium under thermonuclear explosion conditions

Abstract

model. Comparison with experiment has been carried out by means of the p- # diagram which is explained later; this enables us to obtain, for certain approximations, information about the behavior of the radiative neutron capture cross sections of the starting materials from the experimental values of the relative yields of heavy isotopes of the transuranic elements. This comparison shows that the cross sections calculated in this paper describe well the experimental dependence of the radiative neutron capture cross sections on the parity of the isotope and its mass number, at least in the region of 250 ~ A ~ 257. The results of the calculation also indicate a very important fact in the formation under explosion conditions of the final heavy isotopes of the transuranic elements: depending on the radiative neutron capture cross section and the mass number, there must be a significant gap in the region of mass numbers 165 + Z ~ A ~ 168 + Z of the isotopes of the starting material, where Z is the atomic number of the starting material. In the case when the starting material is neptunium this region is found to be within the limits 258 %<A4 261.