Cross sections for the ($p,p\alpha$) reaction at 101.5 MeV have been measured for nine nuclei ranging from ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$ to ${}_{}{}^{66}{}_{}{}^{}\mathrm{Zn}$. Distorted-wave impulse approximation analyses of the ground state transitions provide relative alpha-cluster spectroscopic factors in qualitative agreement with (${}_{}{}^6{}_{}{}^{}\mathrm{Li},d$) studies, although quantitative differences exist. The calculations are sensitive to the bound alpha-cluster parametrization, so that the experimental data suggest limits on the rms radius of the cluster-core wave function.

NUCLEAR REACTIONS ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$, ${}_{}{}^{20}{}_{}{}^{}\mathrm{Ne}$, ${}_{}{}^{24}{}_{}{}^{}\mathrm{Mg}$, ${}_{}{}^{28}{}_{}{}^{}\mathrm{Si}$, ${}_{}{}^{32}{}_{}{}^{}\mathrm{S}$, ${}_{}{}^{40}{}_{}{}^{}\mathrm{Ca}$, ${}_{}{}^{48}{}_{}{}^{}\mathrm{Ti}$, ${}_{}{}^{54}{}_{}{}^{}\mathrm{Fe}$, ${}_{}{}^{66}{}_{}{}^{}\mathrm{Zn}$ ($p,p\alpha$), $E=101.5\mathrm{}$ MeV; Measured ($E_p,E_{\alpha },{\theta }_p,{\theta }_{\alpha }$); DWIA analysis; deduced spectroscopic factors.

• Received 19 August 1980

DOI:https://doi.org/10.1103/PhysRevC.23.576