Study of Proton Resonances in 22Mg by Resonant Elastic Scattering of 21Na+p and Its Astrophysical Implication in 18Ne(α,p)21Na Reaction Rate

摘要

Proton resonant states in 22Mg have been investigated by the resonant elastic scattering of 21Na+p.The 21Na beam with a mean energy of 4.00 MeV/u was separated by the CNS radioactive ion beam separator(CRIB) and bombarded a thick(CH2),target.The energy spectra of recoiled protons were measured at scattering angles of θcm～172° and 146°,respectively.A new state at 7.06 MeV has been observed clearly and another new one at 7.28 MeV is tentatively identified due to its low statistics.The proton resonant parameters were deduced from an R-matrix analysis of the differential cross section data.The astrophysical resonant reaction rate for the 18Ne(α,p) 21Na reaction has been estimated,and it is about five times larger than that assumed before.