Fission Following Transfer toTh232at Energies below the Coulomb Barrier

We have observed fission induced by transfer to ${}_{}{}^{232}{}_{}{}^{}\mathrm{Th}$ from ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$ and ${}_{}{}^{19}{}_{}{}^{}\mathrm{F}$ projectiles at sub-Coulomb energies. The cross sections for the stronger reactions are in qualitative agreement with simple theoretical estimates. They are of the same magnitude as those found earlier by bombardment with Kr and Xe where the $Q$ windows are considerably less favorable. In those cases, transfer involving Coulomb excitation is proposed as an explanation.