Elsevier

Nuclear Physics A

Volume 305, Issue 1, 31 July 1978, Pages 293-312
Nuclear Physics A

12C(7Li, t)16O and stellar helium fusion

https://doi.org/10.1016/0375-9474(78)90179-3Get rights and content

Abstract

The reaction 12C(7Li, t)16O has been studied at E(7Li) = 34 MeV with the LASL tandem accelerator and QDDD magnetic spectrometer. Angular distributions to levels with Ex < 11 MeV have been obtained from 0° to 90°, including 0°. The results have been analyzed with finite-range distorted-wave Born approximation theory. The α-particle spectroscopic factors and reduced widths obtained are compared with those calculated with group theory (SU(3)) and other models. The analysis of data for the 7.1 and 9.6 MeV Jπ = 1 levels, which are of great importance in stellar helium buring, yields a ratio, R, of dimensionless reduced α-widths θ2a(7.1 MeV)θ2a(9.6 MeV) = 0.35b ± 0.13. The observed line width of the 9.6 MeV level (Γc.m. = 390 ± 60 keV) is less than the accepted value (Γc.m. = 510 ± 60 keV) and implies θ2a(9.6 MeV) ≈ 0.6. These results as well as data for the 6.92 MeV Jπ = 2+ and 10.35 MeV Jπ = 4+ “α-cluster” states indicate 0.09 < θ2a(7.1 MeV) < 0.33 with a mean value θ2a(7.1 MeV) = 0.14 ± 0.04. The implication for stellar helium burning is discussed.

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    Supported in part by the National Science Foundation.

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