Study of the reaction of astrophysical interest 60Fe(n,γ)61Fe via (d,pγ) transfer reaction

by Sandra Giron

Wednesday 25 Jul 2012, 14:30 → 15:10 Europe/Zurich

26-1-022 (CERN)

60Fe is of special interest in nuclear astrophysics. Indeed the recent observations of 60Fe caracteristic gamma-ray lines by the RHESSI and INTEGRAL spacecrafts allowed to measure the total flux of 60Fe over the Galaxy. Moreover the observation in presolar grains of an excess of 60Ni, the daughter nuclei of 60Fe, gives constraints on the conditions of formation of the early solar system. However, the cross-sections of some reactions involved in 60Fe nucleosynthesis and included to stellar models are still uncertain. The destruction reaction of 60Fe, 60Fe(n,γ)61Fe, is one of them. The total crosssection can be separated into two contributions: the direct one, involving states below the neutron separation threshold of 61Fe, and the resonant one.

60Fe(n,γ)61Fe reaction was studied via the d(60Fe,pγ) transfer reaction at LISE/GANIL, with an experimental setup made of two beam tracking detectors, four MUST2 telescopes and four EXOGAM clovers. 61Fe spectroscopy was improved in order to evaluate the direct capture part of 60Fe(n,γ)61Fe reaction cross-section. DWBA analysis of experimental proton differential crosssections, which allowed to extract orbital angular momentum and spectroscopic factors of the populated states of 61Fe below the neutron threshold, will be presented. Finally, our experimental results will be compared to shell-model calculations.