Neutrons and photons are characteristically emitted during the nuclear fission process when a deformed, neutron-rich nucleus divides into two fragments that then deexcite. During deexcitation, neutrons are emitted first, followed by photons; this process gives rise to correlated emissions. Few data exist on event-by-event neutron-photon correlation. In this work, ${}^{252}\mathrm{Cf}\left(\mathrm{s}\mathrm{f}\right)$ neutron and photon correlations were measured with an array of 45 liquid organic scintillation detectors and a fission chamber. The measured correlations are compared with MCPNX-PoliMi simulations using the built-in model and two event-by-event fission models, CGMF and FREYA, which predict correlations in prompt emissions from fission. Experimental results suggest weak neutron-photon competition during fragment deexcitation.

• Received 23 January 2018
• Corrected 22 May 2018

DOI:https://doi.org/10.1103/PhysRevC.97.044622