The Totaln−pScattering Cross Section at 4.75 Mev

Physical Review1953Vol. 89(1), pp. 204–222

Citations Over TimeTop 10% of 1953 papers

E. M. Hafner, W.F. Hornyak, Charles E. Falk, G. A. Snow, T. Coor

Abstract

Attenuation measurements in good geometry on polyethylene and graphite scatterers with transmissions from 0.30 to 0.65 have been made. A thin-walled gas target was used, producing forward $d\ensuremath{-}d$ neutrons at a mean energy of 4.749\ifmmode\pm\else\textpm\fi{}0.009 Mev. Care was taken to minimize uncertainties arising from neutrons of other energies, from unshadowed background, and from impurities in the samples. The geometry was such that multiple scattering-in contributed no more than 0.12 percent to the total uncertainty. Checks against rate-dependent sensitivity of the detector revealed no effects greater than 0.15 percent. The total $n\ensuremath{-}p$ scattering cross section deduced from the measurements is 1.690\ifmmode\pm\else\textpm\fi{}${0.006}_{6}$ barns, where the probable error has been increased from the statistical error of ${0.002}_{4}$ barn to include the energy uncertainty and estimates of possible systematic effects. Values of ${{r}_{0s}}^{(n\ensuremath{-}p)}$, the singlet effective range of the $n\ensuremath{-}p$ interaction, obtained from this result for several potential shapes, are compared with corresponding values of ${{r}_{0s}}^{(p\ensuremath{-}p)}$. The validity of the hypothesis of charge independence is found to depend on the potential shape assumed.

Citations Over TimeTop 10% of 1953 papers

Abstract

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