Study of Astrophysically Important Excited States of 30S via the 28Si(3He,n\gamma )30S

Abstract

The 29 P(p, γ) 30 S reaction rate strongly affects explosive hydrogen burning in classical novae and type I X-ray bursts, and depends on the structure of proton unbound 30 S states. The rate in the temperature characteristic of nucleosynthesis in novae and X-ray bursts had been previously predicted to be dominated by two low-lying, unobserved, J π = 3 + and 2 + resonances above the proton threshold in 30 S. Since then, two states have been found at 4699(6) keV and 4814(3) keV, which were tentatively assigned to be the 3 + and 2 + states, respectively. To confirm the existence of these two levels and their energies, the structure of 30 S was investigated via an in-beam γ-ray spectroscopy experiment using the 28 Si( 3 He, nγ) 30 S reaction at University of Tsukuba Tandem Accelerator Complex in Japan. This work describes the experimental setup and presents the preliminary results.11th Symposium on Nuclei in the Cosmos