Scattering of 220-Mev Polarized Protons by Complex Nuclei

Abstract

Extending earlier measurements, we have studied yields and asymmetries in the scattering of a highly polarized proton beam by ${\mathrm{Be}}^9$, ${\mathrm{C}}^{12}$, ${\mathrm{Al}}^{27}$, and ${\mathrm{Ca}}^{40}$. In the work on ${\mathrm{Be}}^9$ and ${\mathrm{Al}}^{27}$, the beam was monochromatized through the use of a regenerative deflector; its mean energy on striking the targets was 219.6 Mev, and its standard deviation in energy (including the effect of short time fluctuations) was less than 1.1 Mev. With this technique, together with a refined procedure for the analysis of the distribution in range of scattered protons, we have been able to separate elastic from inelastic scattering in ${\mathrm{Be}}^9$ at angles from 8° to 37.5°, and to estimate the inelastic scattering involving the excited state at 2.4 Mev. The separation of elastic scattering in ${\mathrm{Ca}}^{40}$ could also be made, although the regenerator was not used. The results are compared with approximate calculations based on the optical model with $\sigma ·\mathrm{L}$ coupling; a potential is found such that, with variation of the nuclear radius alone, good fits are obtained to measurements on the four nuclei.