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- Fougeres, Chloe, et al.
(author)
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Search for Na-22 in novae supported by a novel method for measuring femtosecond nuclear lifetimes
- 2023
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In: Nature Communications. - : Springer Nature. - 2041-1723. ; 14:1
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Journal article (peer-reviewed)abstract
- Classical novae are thermonuclear explosions in stellar binary systems, and important sources of Al-26 and Na-22. While ? rays from the decay of the former radioisotope have been observed throughout the Galaxy, Na-22 remains untraceable. Its half-life (2.6 yr) would allow the observation of its 1.275 MeV ?-ray line from a cosmic source. However, the prediction of such an observation requires good knowledge of its nucleosynthesis. The Na-22(p, ?)Mg-23 reaction remains the only source of large uncertainty about the amount of Na-22 ejected. Its rate is dominated by a single resonance on the short-lived state at 7785.0(7) keV in Mg-23. Here, we propose a combined analysis of particle-particle correlations and velocity-difference profiles to measure femtosecond nuclear lifetimes. The application of this method to the study of the Mg-23 states, places strong limits on the amount of Na-22 produced in novae and constrains its detectability with future space-borne observatories. The authors report a particle-particle correlation and velocity-difference profile method to measure nuclear lifetime. The results obtained for excited states of 23Mg are used to constrain the production of 22Na in the astrophysical novae explosions.
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2. |
- Åberg, Sven, et al.
(author)
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Chaos in the Nucleus: SD Decay-out and Masses
- 2004
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In: AIP Conference Proceedings. - : AIP. - 0094-243X .- 1551-7616. ; 701, s. 213-221
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Conference paper (peer-reviewed)abstract
- Some consequences of chaos in the nucleus are discussed. The decay-out from superdeformed band occurs in a region where normal-deformed states may be chaotic, and it is shown how the distribution of decay-out matrix elements may reveal the degree of chaos. The decay-out is mediated by doorway states that are not resolved in the A=190 region, but experimentally seen in 59Cu. A model for the decay-out in the A=60 region is set up and applied to 59Cu. It is discussed how errors in nuclear mass formula may be related to chaotic motion, and a theoretical model is set up and applied to chaotic masses.
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