X-ray bursts are very luminous thermonuclear explosions that occur in binary star systems. In these systems, a neutron star accreting matter from a companion star undergoes a runaway thermonuclear explosion, caused by a breakout from the CNO-cycle into the αp-process. The αp-process consists of a series of (α,p) and (p,γ) reactions. In this process, there are “waiting point” nuclei at which the nuclear burning pauses until the stellar conditions change so that the (α,p) reaction rate increases and burning continues. 34Ar is one of these waiting point nuclei, and sensitivity studies have found that varying the 34Ar(α,p)37K reaction rate significantly impacts the light curve of x-ray bursts.Because the 34Ar(α,p)37K cross section had never been directly measured before, the reaction rates used in simulations are based on Hauser-Feshbach predictions. These predictions are hypothesized to be inaccurate because the Hauser-Feshbach statistical model requires a high level density in the compound nucleus and assumes there are no dominant resonances.This thesis describes an experiment at the National Superconducting Cyclotron Laboratory (NSCL) designed to test Hauser-Feshbach predictions by directly measuring the 34Ar(α,p)37K cross section. A radioactive ion beam of 34Ar15+ with energies of 57.04 MeV and 54.19 MeV was delivered to a (5–8) × 10^18 atoms/cm^2 thick He target, created by the Jet Experiments in Nuclear Structure and Astrophysics (JENSA) gas jet target. The recoils and beam were detected by the ANASEN position-sensitive ionization chamber, and the ejectiles were detected by an array of silicon detectors combining SuperORRUBA and SIDAR. The beam included contamination from the decay products of 34Ar, namely 34Cl and 34S. While the contribution from 34S(α,p)37Cl could be subtracted because the cross section had be previously measured, the contributions from 34Cl(α,p)37Ar and 34Ar(α,p)37K could not be separated, so a combined cross section for the two was derived from the data.The combined 34Cl(α,p)37Ar and 34Ar(α,p)37K cross sections were determined to be (70 ± 21) mb at (5.91 ± 0.08) MeV and (52 ± 13) mb at (5.51 ± 0.08) MeV in the center of mass frame. Comparison with Hauser-Feshbach theory indicates that the experimental cross sections are lower by 37 % and 20 %, for the two energies, respectively. This suggests that the hypothesis that the Hauser-Feshbach model overestimates the 34Ar(α,p)37K cross section by 2 orders of magnitude is unlikely to be true at these energies.
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