Formation cross sections of several fission products have been determined using the recoil catcher technique followed by γ-ray spectrometry in ${}_{}{}^{19}{}_{}{}^{}\mathrm{F}$ induced fission of ${}_{}{}^{232}{}_{}{}^{}\mathrm{Th}$ at ${\mathit{E}}_{\mathrm{lab}}$=95 and 112 MeV. The data show significant admixture of fission from compound nuclei formed by complete fusion as well as targetlike nuclei formed by transfer reactions. Mass distributions for both the fissioning systems have been obtained using the systematics of charge distribution in low and medium energy fission. Mass distribution for complete fusion fission is broad Gaussian whereas it is asymmetric for transfer induced fission. At 95 MeV the transfer fission constitutes about 28% of total fission cross section while at 112 MeV it is about 14%, showing that the transfer fission fraction decreases with increasing projectile energy across the barrier. The evaporation residue cross sections of the targetlike nucleus formed in the ${}_{}{}^{232}{}_{}{}^{}\mathrm{Th}$ ${(}^{19}$F, ${}_{}{}^{18}{}_{}{}^{}\mathrm{O}$) ${}_{}{}^{233}{}_{}{}^{}\mathrm{Pa}$ reaction were also measured. The evaporation residue cross sections and the calculated decay probabilities of the targetlike nucleus ${}_{}{}^{233}{}_{}{}^{}\mathrm{Pa}$ by PACE2 have been used to estimate the fraction of proton and α transfer fission in the total transfer fission cross section. © 1996 The American Physical Society.

• Received 21 March 1995

DOI:https://doi.org/10.1103/PhysRevC.53.796