Monte Carlo algorithm for calculating pre-neutron fragment mass and kinetic energy distributions from measurements using the 2E Technique for reaction 235U(nth,f)

A nuclear fission event of an actinide results in the formation of two complementary primary fragments with masses (A, A'), which subsequently acquire kinetic energies (E, E') due to Coulomb repulsion. Following this, they emit (n, n') prompt neutrons, isotropically relative to their respective centers of mass, each with their respective kinetic energies. Consequently, due to recoil effects, the fragments reach the detectors with altered kinetic energies (e, e'). This study simulates an experiment using the 2E technique, intending to measure the distribution of (e, e') and (n, n'), from which it aims to infer the distribution of A, E and the average prompt neutron multiplicity as a function of pre-neutron fragment mass. For this purpose, a distribution of primary quantities is assumed as input to a Monte Carlo simulation algorithm of the experiment, whose output data should reproduce the values observed in that experiment.