تقرير
Doppler Broadening in $^{20}$Mg($\beta p\gamma$)$^{19}$Ne Decay
| العنوان: | Doppler Broadening in $^{20}$Mg($\beta p\gamma$)$^{19}$Ne Decay |
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| المؤلفون: | Glassman, Brent E., Pérez-Loureiro, David, Wrede, Chris, Allen, Jacob, Bardayan, Dan W., Bennett, Michael B., Chipps, Kelly A., Febbraro, Michael, Friedman, Moshe, Fry, Cathleen, Hall, Matt, Hall, Oscar, Liddick, Sean N., O'Malley, Patrick, Ong, Wei Jia, Pain, Steven D., Schwartz, Sarah, Shidling, Praveen, Sims, Harry, Thompson, Paul, Zhang, Helin |
| المصدر: | Phys. Rev. C 99, 065801 (2019) |
| سنة النشر: | 2019 |
| المجموعة: | Nuclear Experiment |
| مصطلحات موضوعية: | Nuclear Experiment |
| الوصف: | Background: The $^{15}$O($\alpha ,\gamma$)$^{19}$Ne bottleneck reaction in Type I x-ray bursts is the most important thermonuclear reaction rate to constrain experimentally, in order to improve the accuracy of burst light-curve simulations. A proposed technique to determine the thermonuclear rate of this reaction employs the $^{20}$Mg($\beta p\alpha$)$^{15}$O decay sequence. The key $^{15}$O($\alpha ,\gamma$)$^{19}$Ne resonance at an excitation of 4.03 MeV is now known to be fed in $^{20}$Mg($\beta p\gamma$)$^{19}$Ne; however, the energies of the protons feeding the 4.03 MeV state are unknown. Knowledge of the proton energies will facilitate future $^{20}$Mg($\beta p \alpha$)$^{15}$O measurements. Purpose: To determine the energy of the proton transition feeding the 4.03 MeV state in $^{19}$Ne. Method: A fast beam of $^{20}$Mg was implanted into a plastic scintillator, which was used to detect $\beta$ particles. 16 high purity germanium detectors were used to detect $\gamma$ rays emitted following $\beta p$ decay. A Monte Carlo method was used to simulate the Doppler broadening of $^{19}$Ne $\gamma$ rays and compare to the experimental data. Results: The center of mass energy between the proton and $^{19}$Ne, feeding the 4.03 MeV state, is measured to be 1.21${^{+0.25}_{-0.22}}$ MeV, corresponding to a $^{20}$Na excitation energy of 7.44${^{+0.25}_{-0.22}}$ MeV. Absolute feeding intensities and $\gamma$-decay branching ratios of $^{19}$Ne states were determined including the 1615 keV state. A new $\gamma$ decay branch from the 1536 keV state in $^{19}$Ne to the ground state is reported. The lifetime of the 1507 keV state in $^{19}$Ne is measured to be 4.3${^{+1.3}_{-1.1}}$ ps resolving discrepancies in the literature. Conflicting $^{20}$Mg($\beta p$) decay schemes in published literature are clarified. Comment: 11 pages, 13 figures |
| نوع الوثيقة: | Working Paper |
| DOI: | 10.1103/PhysRevC.99.065801 |
| URL الوصول: | http://arxiv.org/abs/1901.01966 |
| رقم الأكسشن: | edsarx.1901.01966 |
| قاعدة البيانات: | arXiv |
| DOI: | 10.1103/PhysRevC.99.065801 |
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