Three-hump fission barrier in Th232

Subbarrier photofission cross-sections and the fission half-lives have been calculated for $^{232}\mathrm{Th}$ in terms of a suitable three-hump fission barrier model consistent with the suggestion of M\"oller and Nix. The competition due to the gamma deexcitation to the shape-isomeric state in the second well (and its consequent fission) has been included by introducing an absorptive part in the potential in the second well region. The calculated cross sections reproduce satisfactorily the recently observed "shelf" in the deep-subbarrier energy region and provide a further quantitative evidence in favor of resolving the "thorium anomaly" along the lines suggested by M\"oller and Nix.NUCLEAR REACTIONS Fission, calculated subbarrier photofission cross-sections and fission half-lives using a three-hump fission barrier in $^{232}\mathrm{Th}$. Results reproduce the observed "shelf" in the cross-sections in deep-subbarrier energy region.