Induced fission modes of Fermium and Nobelium isotopes.

The mass distributions of fragments resulting from the fission of the isotopes of Fm and No at excitation energies 0–50 MeV are studied with the statistical scission-point fission model. The available experimental mass distributions in the spontaneous and thermal-neutron-induced fission are well described and the origin of transition between asymmetric and symmetric fission modes with variations of neutron number and excitation energy is explored. [ABSTRACT FROM AUTHOR]