Two-proton-transfer reactionsPb208(C12,Be10)Po210andPb208(O16,C14)Po210

Abstract

Levels in ${}_{}{}^{210}{}_{}{}^{}\mathrm{Po}$ have been investigated using the two-proton-transfer reactions (${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$, ${}_{}{}^{10}{}_{}{}^{}\mathrm{Be}$) and (${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$, ${}_{}{}^{14}{}_{}{}^{}\mathrm{C}$) on ${}_{}{}^{208}{}_{}{}^{}\mathrm{Pb}$ at incident energies $E\left({}_{}{}^{12}{}_{}{}^{}\mathrm{C}\right)=78\mathrm{}$ MeV and $E\left({}_{}{}^{16}{}_{}{}^{}\mathrm{O}\right)=104\mathrm{} \mathrm{and} 140$ MeV. Reaction products were identified and energies measured with a magnetic spectrometer and a focal-plane resistive-wire proportional counter. Many levels in ${}_{}{}^{210}{}_{}{}^{}\mathrm{Po}$ were observed up to an excitation energy of about 8 MeV. The results have been analyzed using distorted-wave Born approximation, and shell-model wave functions for levels in ${}_{}{}^{210}{}_{}{}^{}\mathrm{Po}$ have been tested. The $0^{+}$ → $0^{+}$ (g.s.) transition is enhanced by a factor ∼8 compared with the expected strength for a pure ${\left(\pi h_{\frac{9}{2}}\right)}^2$ $0^{+}$ configuration for ${}_{}{}^{210}{}_{}{}^{}\mathrm{Po}$(g.s.). The dependence of the cross sections on projectile and target structure is discussed.