Proton elastic scattering on light nuclei. II. Nuclear structure effects

Abstract

Differential cross sections for proton scattering on 61 nuclei with mass numbers between 9 and 70 were measured at 35.2 MeV incident energy. To extend previous measurements further data were collected at 29.7 MeV on 10 nuclei. From a detailed inspection of the data a definite correlation emerges between the elastic and inelastic cross section values at backward angles and the quadrupole deformation parameters ${\ensuremath{\beta}}_{2}$. Nuclear structure effects are also evident at forward angles at the filling of the $1p$ shell. A set of mass dependent optical-model parameters which produces acceptable fits at forward angles was derived. The imaginary part was found to contain terms connected with the above structure effects. The results of this and of a coupled-channels analysis are discussed.NUCLEAR REACTIONS Proton scattering on $^{9}\mathrm{Be}$, $^{10,11}\mathrm{B}$, $^{12,13}\mathrm{C}$, $^{14,15}\mathrm{N}$, $^{16,17,18}\mathrm{O}$, $^{19}\mathrm{F}$, $^{20,22}\mathrm{Ne}$, $^{23}\mathrm{Na}$, $^{24,25,26}\mathrm{Mg}$, $^{27}\mathrm{Al}$, $^{28,29,30}\mathrm{Si}$, $^{31}\mathrm{P}$, $^{32,34}\mathrm{S}$, $^{35,37}\mathrm{Cl}$, $^{40}\mathrm{Ar}$, $^{39,41}\mathrm{K}$, $^{40,42,43,44,48}\mathrm{Ca}$, $^{45}\mathrm{Sc}$, $^{46,47,48,50}\mathrm{Ti}$, $^{51}\mathrm{V}$, $^{50,52,53,54}\mathrm{Cr}$, $^{55}\mathrm{Mn}$, $^{54,56,58}\mathrm{Fe}$, $^{59}\mathrm{Co}$, $^{58,60,61,62,64}\mathrm{Ni}$, $^{63,65}\mathrm{Cu}$, and $^{64,66,67,68,70}\mathrm{Zn}$; ${E}_{p}=35.2$ MeV. On $^{23}\mathrm{Na}$, $^{31}\mathrm{P}$, $^{39}\mathrm{K}$, $^{45}\mathrm{Sc}$, $^{51}\mathrm{V}$, $^{50,53,54}\mathrm{Cr}$, and $^{62,64}\mathrm{Ni}$ at ${E}_{p}=29.7$ MeV. Measured $\ensuremath{\sigma}(\ensuremath{\vartheta})$ for elastic and inelastic scattering to ${2}_{1}^{+}$ states. Optical-model and coupled-channel analysis. Deduced optical-model parameters and ${\ensuremath{\beta}}_{2}$ quadrupole deformation parameters.