Speaker
Description
The recently developed multiband dispersive optical model with soft rotator nuclear model couplings is used to build a regional potential for fissile actinides. The model allows coupled-channel calculations for odd-A targets considering rotational bands built on vibrational states. Those complex vibrational states are characterized by a coupling of single-particle excitations with the vibrational states of the corresponding even-even core.
We studied fissile targets ${}^{233}$U, ${}^{235}$U, ${}^{239}$Pu, and ${}^{241}$Pu and derive optical model parameters to predict "optical" cross section data. For ${}^{233}$U, the ENSDF database identifies two bands (beta- and octupole vibrations), one band for ${}^{239}$Pu and one band for ${}^{241}$Pu (octupole). For ${}^{235}$U no such bands are found, however the new model can predict cross sections in this case due to the inclusion of the centrifugal stretching effect across the ground state rotational band.
Experimental data on nucleon scattering from ${}^{233}$U, ${}^{235}$U and ${}^{239}$Pu are described using this model as implemented in the OPTMAN code with four nuclear deformations as fitting parameters. Optical predictions for ${}^{235m}$U and ${}^{241}$Pu are also studied.
Derived optical model potentials are being used elsewhere for on-going INDEN evaluations of neutron induced reactions on ${}^{239}$Pu and ${}^{233}$U targets.