Unbound States of \u3csup\u3e32\u3c/sup\u3eCl relevant for Novae

The 31S(p,γ?)32Cl proton-capture reaction is expected to be the dominant breakout pathway of the SiP cycle, which is important for understanding nucleosynthesis in some novae [1]. At novae temperatures, the 31S(p,γ?)32Cl reaction rate is dominated by 31S+p resonances. Discrepancies in the 32Cl resonance energies were reported in previous measurements [1, 2]. We used the 32S(3He,t)32Cl charge-exchange reaction to produce unbound states in 32Cl and determine their excitation energies by detecting tritons at the focal plane of the Enge Spectrograph at the Yale University\u27s Wright Nuclear Structure Laboratory. Proton branching ratios were determined by detecting the decay protons coming from the residual 32Cl states using a silicon array in the spectrometer\u27s target chamber. The improved energy values of excited levels in 32Cl and measurements of the proton-branching ratios should significantly improve our understanding of the 31S(p,γ?)32Cl reaction rate. © Copyright owned by the author(s

The 6Li(22Ne, 26Mg)d α-transfer experiment for the study of low-energy resonances in 22Ne(α,γ)26Mg

While the reaction 22Ne(α,n)25Mg is considered an important neutron source for the s process in massive stars, the competing 22Ne(α,γ)26Mg reaction may be of considerable strength and could significantly suppress the neutron production. For a better understanding of this neutron source, the branching ratio of n and γ partial widths (Γn, Γγ) and spectroscopic information such as energies and spins of 26Mg resonance states within the Gamow window (Eα = 400-1000 keV) should be experimentally determined with improved accuracy. In the present work, we propose to use the 6Li(22Ne, 26Mg)d α-transfer reaction to investigate those resonance parameters and have tested the feasibility of the experiment

X-ray Burst Studies with the JENSA Gas Jet Target

When a neutron star accretes hydrogen and helium from the outer layers of its companion star, thermonuclear burning enables the αp-process as a break out mechanism from the hot CNO cycle. Model calculations predict (α, p) reaction rates significantly affect both the light curves and elemental abundances in the burst ashes. The Jet Experiments in Nuclear Structure and Astrophysics (JENSA) gas jet target enables the direct measurement of previously inaccessible (α,p) reactions with radioactive beams provided by the rare isotope re-accelerator ReA3 at the National Superconducting Cyclotron Laboratory (NSCL), USA. JENSA is going to be the main target for the Recoil Separator for Capture Reactions (SECAR) at the Facility for Rare Isotope Beams (FRIB). Commissioning of JENSA and first experiments at Oak Ridge National Laboratory (ORNL) showed a highly localized, pure gas target with a density of ∼1019 atoms per square centimeter. Preliminary results are presented from the first direct cross section measurement of the 34Ar(α, p)37 K reaction at NSCL

X-ray burst studies with the JENSA gas jet target

When a neutron star accretes hydrogen and helium from the outer layers of its companion star, thermonuclear burning enables the αp-process as a break out mechanism from the hot CNO cycle. Model calculations predict (α, p) reaction rates significantly affect both the light curves and elemental abundances in the burst ashes. The Jet Experiments in Nuclear Structure and Astrophysics (JENSA) gas jet target enables the direct measurement of previously inaccessible (α,p) reactions with radioactive beams provided by the rare isotope re-accelerator ReA3 at the National Superconducting Cyclotron Laboratory (NSCL), USA. JENSA is going to be the main target for the Recoil Separator for Capture Reactions (SECAR) at the Facility for Rare Isotope Beams (FRIB). Commissioning of JENSA and first experiments at Oak Ridge National Laboratory (ORNL) showed a highly localized, pure gas target with a density of ∼1019 atoms per square centimeter. Preliminary results are presented from the first direct cross section measurement of the 34Ar(α, p)37 K reaction at NSCL

X-ray burst studies with the JENSA gas jet target

When a neutron star accretes hydrogen and helium from the outer layers of its companion star, thermonuclear burning enables the αp-process as a break out mechanism from the hot CNO cycle. Model calculations predict (α, p) reaction rates significantly affect both the light curves and elemental abundances in the burst ashes. The Jet Experiments in Nuclear Structure and Astrophysics (JENSA) gas jet target enables the direct measurement of previously inaccessible (α,p) reactions with radioactive beams provided by the rare isotope re-accelerator ReA3 at the National Superconducting Cyclotron Laboratory (NSCL), USA. JENSA is going to be the main target for the Recoil Separator for Capture Reactions (SECAR) at the Facility for Rare Isotope Beams (FRIB). Commissioning of JENSA and first experiments at Oak Ridge National Laboratory (ORNL) showed a highly localized, pure gas target with a density of ∼1019 atoms per square centimeter. Preliminary results are presented from the first direct cross section measurement of the 34Ar(α, p)37 K reaction at NSCL