A technique of solving an ill-posed inverse problem of neutron spectrum unfolding using a genetic algorithm search within Monte Carlo iterations
Department of Physics, Alagappa University, 630002, Karaikudi, India
2 Manipal Centre for Natural Sciences, Manipal Academy of Higher Education, 576104, Manipal, India
Accepted: 13 April 2021
Published online: 26 April 2021
Investigations are done on the technique of solving an ill-posed and under-determined problem of unfolding (de-convoluting) neutron energy distributions from measured prompt gamma intensities. The prompt gammas originate from a combined system of high-density polyethylene (HDPE), borated HDPE with lead cover, and are detected by a NaI(Tl) gamma detector. The technique comprises of finding an average of best-fit solutions at the completion of each genetic algorithm (GA) search inside the Monte Carlo loops. It is observed that the average gives the appropriate solution instead of the overall best-fit solution obtained. Different distance functions based on the L1-norm, the L2-norm, the cross-entropy function and the Bhattacharya distance function also show effect on the final solution.
© The Author(s), under exclusive licence to Società Italiana di Fisica and Springer-Verlag GmbH Germany, part of Springer Nature 2021