부산대학교 도서관

The 22 Na (p , γ) 23 Mg reaction is responsible for destruction of the long-lived radionuclide 22 Na produced during nova explosions. Since the reaction proceeds through resonances from levels in 23 Mg above the proton threshold at 7.581 MeV, the properties of these levels such as excitation energies, spins, and parities are crucial ingredients to determine the 22 Na (p , γ) 23 Mg reaction rate. Despite recent studies of these levels, their spins are not well constrained in many cases. We have measured the 24 Mg (p , d) 23 Mg transfer reaction to determine spectroscopic properties of these levels at the Holifield Radioactive Ion Beam Facility at Oak Ridge National Laboratory. The spin of the E x = 7.788 MeV level in 23 Mg is constrained to be J π = (3/2 + , 5/2 + ) through the present work. The astrophysical 22 Na (p , γ) 23 Mg reaction rate at nova temperatures is updated accordingly. Nova nucleosynthesis model calculations using the newly updated 22 Na (p , γ) 23 Mg reaction rate shows that the final weighted abundance of the radionuclide 22 Na is increased by 42% compared to that obtained by using the previous 22 Na (p , γ) 23 Mg reaction rate of Sallaska et al. for a 1.35 M ⊙ ONeMg white dwarf. [ABSTRACT FROM AUTHOR]