A Monte Carlo Simulation of Prompt Gamma Emission from Fission Fragments

Abstract

The prompt fission gamma spectra and multiplicities are investigated through the Monte Carlo code FIFRELIN which is developed at the Cadarache CEA research cen- ter. Knowing the fully accelerated fragment properties, their de-excitation is simulated through a cascade of neutron, gamma and/or electron emissions. This paper presents the recent developments in the FIFRELIN code and the results obtained on the spontaneous fission of 252 Cf. Concerning the decay cascades simulation, a fully Hauser-Feshbach model is compared with a previous one using a Weisskopf spectrum for neutron emis- sion. A particular attention is paid to the treatment of the neutron/gamma competition. Calculations lead using di erent level density and gamma strength function models show significant discrepancies of the slope of the gamma spectra at high energy. The under- estimation of the prompt gamma spectra obtained regardless our de-excitation cascade modeling choice is discussed. This discrepancy is probably linked to an underestimation of the post-neutron fragments spin in our calculation.