BONDI-97: A novel neutron energy spectrum unfolding tool using a genetic algorithm

The neutron spectrum unfolding procedure using the count rate data obtained from a set of Bonner sphere neutron detectors requires the solution of the Fredholm integral equation of the first kind by using complex mathematical methods. This paper reports a new approach for the unfolding of neutron spectra using the Genetic Algorithm tool BONDI-97 (BOnner sphere Neutron DIfferentiation). The BONDI-97 was used as the input for Genetic Algorithm engine EVOLVER to search for a globally optimised solution vector from a population of randomly generated solutions. This solution vector corresponds to the unfolded neutron energy spectrum. The Genetic Algorithm engine emulates the Darwinian “Survival of the Fittest” strategy, the key ingredient of the “Theory of Evolution”. The spectra of 241Am/Be (α,n) and 239Pu/Be (α,n) neutron sources were unfolded using the BONDI-97 tool.