Population Characteristics for Spin and Excitation Energy of Fragments in Thermal Neutron Induced Fission

The characterisation of fragments from nuclear fission in terms of excitation energy and spin population is still a debated subject. We show that data on excitation energy, kinetic energy and spin of the fragments in thermal neutron induced fission of the actinides can be consistently described by the statistical model in nuclear physics. We present an empirical relationship which allows calculating the temperature of fission products at the scission point. From the temperature we derive the distribution functions for excitation, kinetic energy and fragment spin. We compare the results from the statistical model with experimental data from the LOHENGRIN spectrometer at the Institut Laue-Langevin in Grenoble/France.