Elastic Scattering of 22-Mev Alpha Particles

Abstract

The elastic scattering of 22-Mev alpha paticles from silver, gold, and lead has been measured as a function of angle. The differential cross section has been found to follow Rutherford's equation at forward angles but at some critical angle the cross section deviates, first increasing slightly for lead and gold and then decreasing monotonically. The silver distribution shows no increase.The lead and gold data have been fitted with a modification of Blair's sharp angular momentum cut-off theory but there is no satisfactory agreement between theory and experiment for the silver data. Using this type of analysis one is able to find a nuclear radius that follows the $R={r}_{0}{A}^{\frac{1}{3}}$ law with ${r}_{0}=1.5\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}13}$ cm only if one assumes a large size, \ensuremath{\sim}2.5\ifmmode\times\else\texttimes\fi{}${10}^{\ensuremath{-}13}$ cm, for the alpha particle.