Coulomb breakup at high energy in inverse kinematics of proton-rich ${}^{31}\mathrm{Cl}$ was used to constrain the thermonuclear ${}^{30}\mathrm{S}$($p,\gamma$)${}^{31}\mathrm{Cl}$ capture reaction rate under typical Type I x-ray burst conditions. This reaction is a bottleneck during rapid proton-capture nucleosynthesis (rp process), where its rate depends predominantly on the nuclear structure of ${}^{31}\mathrm{Cl}$. Two low-lying states just above the proton-separation threshold of $S_p=296\left(50\right)$ keV in ${}^{31}\mathrm{Cl}$ have been identified experimentally using the R${}^3$B-LAND setup at the GSI Helmholtzzentrum für Schwerionenforschung GmbH. Both states are considered to play a key role in the thermonuclear ${}^{30}\mathrm{S}$($p,\gamma$)${}^{31}\mathrm{Cl}$ capture reaction. Excitation energies of the first $J^{\pi }=1/2^{+},5/2^{+}$ states have been extracted and the reaction rate for proton capture on ${}^{30}\mathrm{S}$ under typical rp-process temperatures has been investigated.

• Received 11 November 2013

DOI:https://doi.org/10.1103/PhysRevC.89.035806