Fission of doubly even actinide nuclei induced by direct reactions

Fission probability distributions have been measured by ($t,pf$), (t,αf), (t,t^'f), (p,p^'f), (³He,df), and (³He,αf) reactions with bombarding energies of 15, 16, 20, 22.5, 24, and 24 MeV, respectively. Using targets of 230,232Th, ²³¹Pa, 234,236,238U, ²³⁷Np, 240,242Pu, ²⁴³Am, and ²⁴⁸Cm the fission decay of 230,232,234Th, 232,236,238,240U, 238,242,244Pu, and 244,248,250Cm was studied. Subbarrier vibrational resonances were observed for ²³⁴Th, 236,238,240U, ²⁴²Pu, and ²⁵⁰Cm. The results are analyzed with a statistical model which involves resonant penetration of the double-humped fission barrier. Estimates of the heights and curvature of the two peaks in the fission barrier are obtained for Th, U, Pu, and Cm isotopes and these values are compared with various theoretical calculations.[NUCLEAR REACTIONS FISSION measured fission probabilities, E*≤7.5 MeV for 230,232,234Th, 232,236,238,240U, 238,242,244Pu, 244,248,250Cm using ($t,pf$), (t,αf), (t,t^'f), (p,p^'f), (³He,df), (³He,αf) reactions; deduced heights and curvatures for the double-peaked fission barrier for each case.]