Breakup of radioactive nuclear beams at intermediate energies as indirect method for nuclear astrophysics
- Cyclotron Institute, Texas A and M University, College Station, TX 77843 (United States)
- Institute for Physics and Nuclear Engineering 'H. Hulubei', Bucharest (Romania)
We discuss the use of one-nucleon removal reactions of loosely bound nuclei at intermediate energies as an indirect method in nuclear astrophysics. These breakup reactions are good spectroscopic tools and can be used to study a large number of loosely bound proton- or neutron-rich nuclei over a wide range of beam energies. They are peripheral processes that can be used to extract asymptotic normalization coefficients (ANC) from which direct capture proton reaction rates of astrophysical interest can be calculated parameter free. We emphasize the importance of reaction model calculations and of exclusive measurements to check them. We review several cases: the breakup of {sup 8}B, {sup 9}C, {sup 15}C and {sup 23}Al. Firrst we review how we have used the data for the breakup of {sup 8}B at energies from 30 to 1000 MeV/nucleon on light and heavy targets to extract the astrophysical factor S{sub 17}(0) = 18.7{+-}1.9 eV{center_dot}b for the key reaction for solar neutrino production. Glauber model calculations in the eikonal approximation and in the optical limit using different effective NN interactions were found to give consistent, though slightly different results, for both {sup 8}B and {sup 9}C cases, enabling also us to evaluate the precision of the method. The third case is that of a neutron-rich nucleus and the ANC alone does not lead to unambiguous estimates of the associated (n,{gamma}) capture reaction. The {sup 23}Al case is that of an sd-shell nucleus, suspected of halo properties, for which our recent GANIL experiment revealed a complex configuration mixing in its ground state. The method outlined here has the big advantage that it can be used for beams of low quality, such as cocktail beams, and intensities as low as a few pps. As such it is very appropriate for the existing and future radioactive beam facilities. The breakup reactions are therefore complementary or a very good alternative to the use of proton and neutron transfer reactions (the ANC method) which require radioactive nuclear beams of much better purity and intensity.
- OSTI ID:
- 21143465
- Journal Information:
- AIP Conference Proceedings, Vol. 1016, Issue 1; Conference: 10. international symposium on origin of matter and evolution of galaxies: From the dawn of Universe to the formation of solar system, Sapporo (Japan), 4-7 Dec 2007; Other Information: DOI: 10.1063/1.2943571; (c) 2008 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0094-243X
- Country of Publication:
- United States
- Language:
- English
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