Scattering of 7.5-Mev Protons by Helium

Abstract

The differential cross section for the elastic scattering of 7.5\ifmmode\pm\else\textpm\fi{}0.1 Mev protons from helium has been measured at 2.5\ifmmode^\circ\else\textdegree\fi{} intervals over the laboratory angular range 10\ifmmode^\circ\else\textdegree\fi{} to 172.5\ifmmode^\circ\else\textdegree\fi{} using the Los Alamos nuclear plate camera. The results obtained have an absolute standard error of \ifmmode\pm\else\textpm\fi{}2.5% to \ifmmode\pm\else\textpm\fi{}3%. A phase-shift analysis of the data gives for the $S$, $P$, and $D$ phase shifts: ${\ensuremath{\delta}}_{0}=\ensuremath{-}57.95\ifmmode^\circ\else\textdegree\fi{}$, ${{\ensuremath{\delta}}_{1}}^{+}=112.1\ifmmode^\circ\else\textdegree\fi{}$, ${{\ensuremath{\delta}}_{1}}^{\ensuremath{-}}=52.51\ifmmode^\circ\else\textdegree\fi{}$, ${{\ensuremath{\delta}}_{2}}^{+}=0.44\ifmmode^\circ\else\textdegree\fi{}$, ${{\ensuremath{\delta}}_{2}}^{\ensuremath{-}}=\ensuremath{-}1.87\ifmmode^\circ\else\textdegree\fi{}$. These results fit the experimental data with a root-mean-square deviation of 2.7% and appear to be in harmony with those determined from experiments at other energies.