August 11-15, 2014


Diffusion coefficients in white dwarfs

Didier Saumon (Los Alamos National Laboratory)

C.E. Starrett (Los Alamos National Laboratory) J.O. Daligault (Los Alamos National Laboratory)

The diffusion of elements in the envelopes of white dwarfs is one of the most important physical processes that determine their atmospheric composition, spectral type, and spectral evolution. Models of white dwarfs universally rely on the diffusion coefficients of Paquette et al (1986, ApJ Supp., 61, 177). We present new calculations of diffusion coefficients based on a more sophisticated microscopic theory of dense plasmas and a numerical simulation approach that intrinsically accounts for multiple collisions. We will present a validation of our method and our first results for the diffusion of carbon ions in a helium plasma.

Mode of presentation: poster