On the excitation energy of the ground state in the third minimum of U-234

Abstract The 233 U(d,pf) 234 U reaction has been studied with high energy resolution. The observed fission resonances in the excitation energy range of 4.75 ≤E ∗ ≤ 5.40 MeV were described as members of rotational bands with rotational parameters characteristic to the hyperdeformed nuclear shape (ℏ 2 /2 θ =2.1±0.2 keV). Information on the K values of the bands has been obtained from fission fragment angular distribution measurements. The level density of the most strongly excited J =3 states has been compared to the prediction of the back-shifted Fermi-gas formula and the energy of the ground state in the third minimum has been estimated to be E III = 3.1 ± 0.4 MeV.