FISSION MODES IN THE COMPOUND NUCLEUS NP-238

Potential energy calculations in conjunction with the multi-modal random neck-rupture model of Brosa, Grossmann and Muller (BGM-model) indicate the existence of four fission modes in the compound nucleus Np-238. For the first time the splitting of the standard mode into three submodes could be demonstrated theoretically. The existence of a third standard mode in fission has already been proposed for heavier nuclei, where a nonnegligible yield of more asymmetric fission fragments is experimentally observed. The calculated fission fragment properties for Np-238 are discussed and compared to experimental results.