Electron Antineutrino Spectrum forU235(n,f)

Abstract

The ${\overline{\ensuremath{\nu}}}_{e}$ spectrum has been computed for fission-product decay following a 30-d irradiation of $^{235}\mathrm{U}$ by thermal neutrons. Estimated uncertainties lie in the range (7-15)% for ${E}_{\overline{\ensuremath{\nu}}}<6$ MeV. Analysis relied on comparisons of calculated $\ensuremath{\beta}$-ray data with recently obtained experimental $\ensuremath{\beta}$-ray spectra. The ${\overline{\ensuremath{\nu}}}_{e}$ spectrum is softer than all other calculated ${\overline{\ensuremath{\nu}}}_{e}$ spectra. Cross sections (${10}^{\ensuremath{-}44}$ ${\mathrm{cm}}^{2}$/fission) were calculated as $\ensuremath{\sigma}({\overline{\ensuremath{\nu}}}_{e}+p\ensuremath{\rightarrow}n+{e}^{+})=58\ifmmode\pm\else\textpm\fi{}3$, $\ensuremath{\sigma}({\overline{\ensuremath{\nu}}}_{e}+d\ensuremath{\rightarrow}n+p+{\overline{\ensuremath{\nu}}}_{e})=2.7\ifmmode\pm\else\textpm\fi{}0.2$, and $\ensuremath{\sigma}({\overline{\ensuremath{\nu}}}_{e}+d\ensuremath{\rightarrow}n+n+{e}^{+})=1.04\ifmmode\pm\else\textpm\fi{}0.13$.