The fission probability of 232Pa was measured as a function of the excitation energy in order to search for hyperdeformed (HD) transmission resonances using the (d,pf) transfer reaction on a radioactive 231Pa target. The experiment was performed at the Tandem accelerator of the Maier-Leibnitz Laboratory (MLL) at Garching using the 231Pa(d,pf) reaction at a bombarding energy of Ed=12 MeV and with an energy resolution of ΔE=5.5 keV. Two groups of transmission resonances have been observed at excitation energies of E*=5.7 and 5.9 MeV. The fine structure of the resonance group at E*=5.7 MeV could be interpreted as overlapping rotational bands with a rotational parameter characteristic to a HD nuclear shape (2/2Θ=2.10±0.15 keV). The fission barrier parameters of 232Pa have been determined by fitting talys 1.2 nuclear reaction code calculations to the overall structure of the fission probability. From the average level spacing of the J=4 states, the excitation energy of the ground state of the third minimum has been deduced to be EIII=5.05-0.10+0.40 MeV.
ASJC Scopus subject areas
- Nuclear and High Energy Physics