Absolute cross sections for proton-induced fission of the uranium isotopes

摘要: Absolute cross sections for proton induced fission have been measured $^{233}\mathrm{U}$, $^{234}\mathrm{U}$, $^{235}\mathrm{U}$, $^{236}\mathrm{U}$, and $^{238}\mathrm{U}$ energies ranging from 5.0 to 30.0 MeV. Angular distributions all isotopes the fragment angular anisotropy determined as a function of excitation energy. Excitation data were accumulated at 250 keV intervals with smaller steps in regions special interest. Fission probabilities calculated optical model predictions prominently display effects due opening additional channels energy is increased. A method analysis formulated demonstrated which makes use extended range selection an isotopic sequence target nuclei unfold contributions section first, second, third chance fission. Using this method, previously undetermined thresholds $\frac{{\ensuremath{\Gamma}}_{n}}{{\ensuremath{\Gamma}}_{f}}$ ratios are estimated individual functions energy.NUCLEAR REACTIONS, FISSION $^{233}\mathrm{U}(p,xnf)$, $^{234}\mathrm{U}(p,xnf)$, $^{235}\mathrm{U}(p,xnf)$, $^{236}\mathrm{U}(p,xnf)$, $^{238}\mathrm{U}(p,xnf)$, $E=5.0\ensuremath{-}30.0$ MeV; ${\ensuremath{\sigma}}_{p,xnf}({E}_{p},\ensuremath{\theta})$; deduced ${\ensuremath{\sigma}}_{\mathrm{fT}}(E)$, $\frac{{\ensuremath{\Gamma}}_{n}}{{\ensuremath{\Gamma}}_{f}}(E,A)$, barriers.