DEVIATIONS FROM RUTHERFORD BACKSCATTERING FOR Z = 1, 2 PROJECTILES

In a previous paper, an analytical expression for the center of mass kinetic energy, E(nr), for departure from Rutherford backscattering was obtained and applied to both proton and He-4 projectiles. This paper further explores the consequences of deviations from Rutherford backscattering, specifically for the charged particle projectiles, Z = 1, 2. In the original model there was no dependence on the nature of the projectile. In this paper, it is shown through the use of both data and optical model calculations that there are two clearly discernable projectile effects, namely an increase in E(nr) as the projectile charge increases and a less pronounced increase in E(nr) for the heaviest of the isotopes in each of the two charge groups. It is then demonstrated how these two effects can be accounted for in terms of the mass and change of the projectile, without changing either the model parameters or results of the previous paper.