Alpha particle elastic scattering from ${}_{}{}^{208}{}_{}{}^{}\mathrm{Pb}$ and the ${}_{}{}^{208}{}_{}{}^{}\mathrm{Pb}$(${}_{}{}^4{}_{}{}^{}\mathrm{He}$,$t$)${}_{}{}^{209}{}_{}{}^{}\mathrm{Bi}$ and ${}_{}{}^{208}{}_{}{}^{}\mathrm{Pb}$(${}_{}{}^4{}_{}{}^{}\mathrm{He}$, ${}_{}{}^3{}_{}{}^{}\mathrm{He}$)${}_{}{}^{209}{}_{}{}^{}\mathrm{Pb}$ reactions have been measured at 39.8, 61.5, and 81.4 MeV. Distorted-wave Born approximation calculations, including finite range effects, provide spectroscopic factors for the lowest levels which are generally energy independent to within 15%. This result is in contrast to published ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$+${}_{}{}^{208}{}_{}{}^{}\mathrm{Pb}$ single nucleon transfer studies which show a factor of approximately four variation in the spectroscopic factor over the same MeV/nucleon energy range.

NUCLEAR REACTIONS ${}_{}{}^{208}{}_{}{}^{}\mathrm{Pb}$($\alpha$,$\alpha$), ($\alpha$,${}_{}{}^3{}_{}{}^{}\mathrm{He}$), ($\alpha$,$t$), $E_{\alpha }=39.8, 61.5, 81.4$ MeV, measured $\sigma \left(\theta \right)$, enriched target; optical model analysis, DWBA analysis, deduced spectroscopic factors.

• Received 25 March 1981

DOI:https://doi.org/10.1103/PhysRevC.24.1471