The 20Ne(d,p)21Ne transfer reaction in relation to the s-process abundances

[摘要] A study of the20Ne(d,p)21Ne transfer reaction was performed using the Quadrupole Dipole Dipole Dipole (Q3D) magnetic spectrograph in Garching, Germany. The experiment probed excitation energies in21Ne ranging from 6.9 MeV to 8.5 MeV. The aim was to investigate the spectroscopic information of21Ne within the Gamow window of core helium burning in massive stars. Further information in this region will help reduce the uncertainties on the extrapolation down to Gamow window cross sections of the17O(α,γ)21Ne reaction. In low metallicity stars, this reaction has a direct impact on s-process abundances by determining the fate of16O as either a neutron poison or a neutron absorber. The experiment used a 22-MeV deuteron beam, with intensities varying from 0.5-1 μA, and an implanted target of20Ne of 7 μg/cm2in 40 μg/cm2carbon foils. Sixteen21Ne peaks have been identified in the Ex= 6.9-8.5 MeV range, of which only thirteen peaks correspond to known states. Only the previously-known Ex= 7.960 MeV state was observed within the Gamow window.

[发布机构] Department of Physics, University of York, Heslington, York; YO10 5DD, United Kingdom^1;Departament de Física i Enginyeria Nuclear, Universitat Politècnica de Catalunya, Barcelona; E-08036, Spain^2;Institut d'Estudis Espacials de Catalunya, Barcelona; E-08034, Spain^3;Department of Physics and Astronomy, McMaster University, Hamilton; ON; L8S 4M1, Canada^4;Maier-Leibnitz Laboratorium, Münchner Universitäten, Garching; D-85748, Germany^5;SUPA, School of Physics and Astronomy, University of Edinburgh, Edinburgh; EH9 3JZ, United Kingdom^6;Oak Ridge National Laboratory (ORNL), Oak Ridge; TN; 37831, United States^7;Institut de Physique Nucléaire d'Orsay, UMR8608, IN2P3-CNRS, Université Paris Sud 11, Orsay; 91406, France^8

[效力级别] 天文学 [学科分类] 天文学(综合)

[关键词] Deuteron beams;Dipole-dipole;Direct impact;Helium-burning;Magnetic spectrographs;Neutron absorbers;Spectroscopic information;Transfer reaction