On the double and triple-humped fission barriers and half-lives of actinide elements

The deformation barriers standing in the quasi-molecular shape path have been determined in the actinide region within a macroscopic-microscopic energy derived from a generalized liquid drop model, the algebraic droplet model shell corrections and analytic expressions for the pairing energies. Double and triple-humped fission barriers appear. The second barrier corresponds to the transition from one-body shapes to two touching ellipsoids. The third minimum and third peak, when they exist, come from shell rearrangements in the deformed fragment. The shape of the other almost magic one is close to the sphere. The barrier heights agreewith the experimental results, the energy of the second minimum being a little too high. The predicted half-lives follow the experimental data trend.