Document Stellar Evolution and Seismic Tools for Asteroseismology - Diffusive Processes in Stars and Seismic Analysis
C.W. Straka, Y. Lebreton and M.J.P.F.G. Monteiro (eds)
EAS Publications Series, 26 (2007) 25-36
DOI: 10.1051/eas:2007123
Microscopic Diffusion in Stellar Plasmas
A. Thoul and J. MontalbánDepartment of Astrophysics and Geophysics, Liège University, 17 allée du 6 août, 4000 Liège, Belgium
(Published online: 20 June 2007)
Abstract
We review the basic equations describing the microscopic diffusion of elements in stars.
We describe the two formalisms commonly used to describe a stellar plasma, i.e.,
the Chapman-Enskog method and the Burgers equations. We point out the underlying assumptions about
the physical state of the plasma itself. We briefly describe the different approximations
which are often used to solve these equations, and discuss their validity.
One of the major problems lies in the calculation of the collision integrals, and we discuss
the different approaches to solving these integrals, emphasizing on their domain of validity.
© EAS, EDP Sciences 2007