On the topographical properties of fission barriers

The fission barrier, given as the difference between the saddle-point and ground-state masses, plays a mandatory role in determining the survival probability of fissile nuclei. While the ground-state mass is strongly influenced by the shell correction, according to the topographic theorem the saddle-point mass should be rather close to its macroscopic value. In the present paper, the topographical properties of fission barriers have been investigated within the macro-microscopic approach. The range of the validity of the topographic theorem was studied in a quantitative way. It is shown that the conditions for the validity of the topographic theorem are fulfilled at the inner barrier, while at the outer saddle-point, deviations caused by the presence of shell effects of the nascent fragments have been found.