Proton-Gamma Angular Correlation Studies ofBe9andCa40(d, pγ)Stripping Reactions

Abstract

To investigate the applicability of the Butler stripping theory, the angular correlations have been measured between the protons and $\gamma$ rays from the reactions ${\mathrm{Be}}^9(d, p\gamma ){\mathrm{Be}}^{10*}$ (3.37 Mev) and ${\mathrm{Ca}}^{40}(d, p\gamma ){\mathrm{Ca}}^{41*}$ (1.95 Mev), using 7.78-Mev deuterons. Both correlations in the ($d, p$) plane are of the form $1+A_2{P}_2\left(cos\theta \right)$, where $\theta$ is the angle between the $\gamma$ ray and the recoil nucleus, as predicted by theory. For ${\mathrm{Be}}^9$ the coefficient $A_2=-0.33\mathrm{}\pm 0.04$, in reasonable agreement with the previously reported value of -0.40±0.05 for a deuteron energy of 4 Mev, and hence confirming the theoretically expected energy independence. This value of $A_2$ is close to that of -0.40 predicted on the assumption of $L-S$ coupling with the assignment of a ${}_{}{}^3{}_{}{}^{}P_2^{}{}_{}{}^{}$ state for the first excited level of ${\mathrm{Be}}^{10}$. For ${\mathrm{Ca}}^{40}$, $A_2=+0.17\mathrm{}\pm 0.04$, in satisfactory agreement with the predicted value of 0.143 obtained by using the reasonable assumption of $j-j$ coupling with less than ${10}^{-3\mathrm{}}$% $M3\mathrm{}$ in the predominantly $E2\mathrm{}$ $\gamma$ transition. Both transitions showed less than 6% effect in the correlation in the plane perpendicular to the recoil axis, in agreement with the isotropy expected from the simplified stripping theory.