Book Description

Measurements of partial 235U(n,2n[gamma]) [gamma]-ray cross sections have been carried out as a function of incident neutron energy using the GEANIE spectrometer at LANSCE/WNR. The yields of [gamma] rays resulting from the population of discrete levels in the residual nucleus 234U have been measured at incident neutron energies in the 1-20-MeV range. These data provide, with the aid of nuclear reaction modeling, a measurement of the 235U(n,2n) reaction cross section and serve as a proof of principle of the y-ray technique for the parallel 23gPu(n,2n) measurement [l]. This paper presents the analysis of the [gamma]-ray data and the extraction of partial [gamma]-ray cross sections as a function of incident neutron energy. Uncertainties associated with the spectroscopic analysis of the data and validation of the results are discussed in detail.