Determination of the 9Be(α,n)12C reaction rate
Abstract
In a neutron-rich, α-rich environment that could arise during a supernova explosion the reaction chain 4He(αn,γ)9Be(α,n)12C dominates the creation of carbon, which leads to the creation of heavier elements in the subsequent r process [S. E. Woosley and R. D. Hoffman, Astrophys. J. 395, 202 (1992); B. S. Meyer, G. J. Matthews, W. M. Howard, S. G. Woosley, and R. D. Hoffman, ibid. 399, 656 (1992); W. M. Howard, S. Goriely, M. Rayet, and M. Arnould, ibid. 417, 713 (1993)]. For this reason the excitation function of the reaction 9Be(α,n)12C has been measured in the energy range from Eα=366 keV up to 3552 keV (corresponding Ec.m.=254-2450 keV in the center-of-mass system) to obtain consistent data in the whole range, which were lacking in the literature. The measurements have been performed with a 4π detector and the yield contributions of the n0 and n1 neutron group could be resolved. Solid metallic targets of thickness 430 Å (7.75 μg/cm2) and 650 Å (11.72 μg/cm2) were used. Reaction rates and an analytic expression for them have been evaluated for 0.001<=T9<=10.
- Publication:
-
Physical Review C
- Pub Date:
- May 1996
- DOI:
- 10.1103/PhysRevC.53.2486
- Bibcode:
- 1996PhRvC..53.2486K
- Keywords:
-
- 25.55.Hp;
- 26.30.+k;
- 27.20.+n;
- Transfer reactions;
- Nucleosynthesis in novae supernovae and other explosive environments;
- 6<
- =A<
- =19