Monte Carlo simulation of γ and fission transfer-induced probabilities using extended 𝓡-matrix theory: Application to the ²³⁷U^∗ system

¹ CEA, DEN, DER, SPRC, Physics Studies Laboratory, Cadarache, 13108 Saint-Paul-lez-Durance, France
² CENBG, CNRS/IN2P3-Université de Bordeaux, Chemin du Solarium, BP. 120, 33175 Gradignan, France

^a e-mail: olivier.bouland@cea.fr

Published online: 13 September 2017

Abstract

This paper deals with simultaneous neutron-induced average partial cross sections and surrogate-like probability simulations over several excitation and de-excitation channels of the compound nucleus. Present calculations, based on one-dimensional fission barrier extended 𝓡-matrix theory using Monte Carlo samplings of both first and second well resonance parameters, avoid the surrogate-reaction method historically taken for surrogate data analyses that proved to be very poor in terms of extrapolated neutron-induced capture cross sections. Present theoretical approach is portrayed and subsequent results can be compared for the first time with experimental γ-decay probabilities; thanks to brand new simultaneous ²³⁸U(³He,⁴Heγ) and ²³⁸U(³He,⁴He f) surrogate measurements. Future integration of our strategy in standard neutron cross section data evaluation remains tied to the developments made in terms of direct reaction population probability calculations.