<p>The astrophysical <sup>30</sup>P(<em>p</em>,<em>γ</em>)<sup>31</sup>S reaction rate is a key quantity used in both classical nova and type I X-ray burst models that predict isotopic abundances produced during nucleosynthesis in the outburst. Currently, uncertainties in <sup>31</sup>S structure parameters lead to a variation in the reaction rate by a factor of 20 at nova temperatures causing predicted isotopic abundance ratios in the Si-Ar mass region to vary by factors of up to 4. The <sup>30</sup>P(<em>p</em>,<em>γ</em>)<sup>31</sup>S reaction rate can be determined indirectly by measuring transfer reactions populating excited states in <sup>31</sup>S. Nuclear structure information for <sup>31</sup>S resonant states above the proton threshold of 6131 keV and within the Gamow window that contribute most significantly to the reaction rate can be used to re-evaluate the rate for nova and type I X-ray burst temperatures and reduce current uncertainties. We have performed an experiment in order to study the level structure of <sup>31</sup>S via the <sup>32</sup>S(<em>d</em>,<em>t</em>)<sup>31</sup>S single-nucleon transfer reaction using the MP tandem accelerator and Q3D magnetic spectrograph at MLL in Munich, Germany. Excited states of <sup>31</sup>S in the 6-7 MeV region were observed and spin-parity constraints have been suggested. In this work we describe the experimental setup, data analysis and results for both experiments and provide recommendations for further investigation of the <sup>30</sup>P(<em>p</em>,<em>γ</em>)<sup>31</sup>S astrophysical reaction rate.</p> / Master of Science (MSc)
| Identifer | oai:union.ndltd.org:mcmaster.ca/oai:macsphere.mcmaster.ca:11375/11918 |
| Date | 04 1900 |
| Creators | Irvine, Dan T. |
| Contributors | Chen, Alan A., Sprung, Donald, Nejat, Reza, Physics and Astronomy |
| Source Sets | McMaster University |
| Detected Language | English |
| Type | thesis |
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