The ^{7}Be Electron Capture Rate in the Sun
Abstract
For solar conditions, we numerically integrate the density matrix equation for a thermal electron in the field of a ^{7}Be ion and other plasma ions and smearedout electrons. With this technique, we can calculate the capture rate without either assuming the existence of bound states or requiring fluctuations to be spherical. Our results are in agreement with previous calculations that are based on a different physical picture, a picture that postulates the existence of distinct continuum and boundstate orbits for electrons. The density matrix calculation of the electron capture rate is independent of the nature of electron states in the solar plasma. To within 1% accuracy, the effects of screening can be described at high temperatures by a Salpeterlike factor of exp (Ze^{2}/kTR_{D}), which can be derived from the density matrix equation. We show that nonspherical fluctuations change the reaction rate by less than 1%. The total theoretical uncertainty in the electron capture rate is about +/2%.
 Publication:

The Astrophysical Journal
 Pub Date:
 November 1997
 DOI:
 10.1086/304854
 arXiv:
 arXiv:astroph/9702065
 Bibcode:
 1997ApJ...490..437G
 Keywords:

 Nuclear Reactions;
 Nucleosynthesis;
 Abundances;
 Astrophysics
 EPrint:
 LaTex, 19 pages, 2 tables, submitted to ApJ