Speaker
Description
The 1275-keV gamma-ray line from decay of the radionuclide $^{22}$Na (${t _ {1/2}}$ = 2.6 y) is a prominent candidate for detection by space-based gamma ray telescopes, including the COSI mission scheduled to launch in 2027. Accurate models of the production and destruction of $^{22}$Na during novae are sought in order to determine the sensitivity required by observational missions as well as to compare to observational results in the future. During the thermonuclear runaway, the main channel through which $^{22}$Na is consumed is proton capture to $^{23}$Mg, and the thermonuclear rate of this reaction is dominated by a single narrow resonance corresponding to a proton energy of 213 keV. Direct measurements of the strength of this resonance are discrepant, and resonance strengths determined indirectly using the proton branching ratio and the lifetime of the associated 7787 keV state in $^{23}$Mg are in further disagreement with both direct measurements. The Doppler Shift Lifetimes 2 (DSL2) setup at the TRIUMF-ISAC II user facility was used to constrain the lifetime of this key state in $^{23}$Mg. Preliminary results for this lifetime will be presented and interpreted in the context of prior nuclear data discrepancies and impact on the nucleosynthesis of $^{22}$Na in nova models.
This material is based upon work supported by the U.S. National Science Foundation under Grant Nos. PHY-1913554, PHY-2209429, and PHY-2514797. We acknowledge the Natural Sciences and Engineering Research Council of Canada. TRIUMF receives federal funding via a contribution agreement through the National Research Council of Canada. The GRIFFIN infrastructure has been funded jointly by the Canada Foundation for Innovation, the British Columbia Knowledge Development Fund (BCKDF), the Ontario Ministry of Research and Innovation (ON-MRI), TRIUMF and the University of Guelph.
| Career stage | Graduate student |
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