Séminaire spécialisé

vendredi 14 décembre 2012 à 15:00


Nuclear astrophysics @ GANIL

François de Oliveira Santos

GANIL Caen, France

With the advent of radioactive beams, new opportunities of studies open up. Recently, several studies related to nuclear astrophysics were performed at GANIL. In particular, a first direct measurement of reaction cross section was performed [1]. This experiment, the simultaneous measurement of the H(18F,α )15O and H(18F,p)18F reactions, is related to the gamma ray emitter 18F and Novae phenomena. The isotope 60Fe is also known as a cosmic gamma ray emitter, which radiation was observed by the spacecraft INTEGRAL, and the reaction 60Fe(n,γ)61Fe was identified as an important reaction for the understanding of its abundance. This reaction was studied at GANIL via the measurement of the transfert reaction 60Fe(d,pγ) [2]. Using the beam of high intensity, good quality and purity obtained using the SPIRAL facility, an accurate measurement of the lifetime of 19O and 19Ne was obtained in different substratum [3]. This study is related to the electron screening effects, which is of prime importance in low energy nuclear reactions and the stellar hydrostatic combustion phase. The measurement of radiative alpha capture reactions is very important in the understanding of the origin of the p-nuclei, medium mass proton rich stable nuclei which origin is probably Supernovae SNII. Exploratory experimental studies are underway.

[1] D. J. Mountford et al Phys. Rev. C 85, 022801 (2012) Published February 6, 2012
[2] Ph.D. Thesis of S. Giron, University of Orsay, France.
[3] Ph.D. Thesis of P. Ujic, University of Caen, France. Article to be submitted.