Effect of differences in proton and neutron density distributions on   fission barriers
  The neutron and proton density distributions obtained in constrained Hartree-Fock-Bogolyubov calculations with the Gogny force along the fission paths of 232Th, 236U, 238U and 240Pu are analyzed.   Significant differences in the multipole deformations of neutron and proton densities are found. The effect on potential energy surfaces and on barrier heights of an additional constraint imposing similar spatial distributions to neutrons and protons, as assumed in macroscopic-microscopic models, is studied. 
J.F. Berger (CEA, SPN, Bruyeres-le-Chatel, France) and K. Pomorski   (University M.C.S., Lublin, Poland)