A note on neutron point kinetics with delayed neutrons and prompt neutrons as separate populations

This note describes the development of a theory of point kinetics with delayed neutrons and prompt neutrons as separated populations. The separated point kinetics are demonstrated to be consistent with the original point kinetics, and are used in three novel applications to: (1) visualise the separate evolution timescales of the two neutron populations, (2) allow us to comment quantitatively on the ‘delayed neutron fraction’ versus ’relative yield’ definitions of the parameter β in favour of the latter, and (3) suggest a possible deficiency that the use of reactivity as a parameter may not be able to accurately model the true physical effects of perturbations to fission production.