Semiclassical model for the ionic self-diffusion coefficient in white dwarfs

Under the extreme conditions of massive white dwarfs, which have ionic densities that exceed 10(29) cm(-3) , the ions can be both very strongly coupled and partially degenerate. We present a simple model for self-diffusion in such white dwarfs that utilizes the known one-component plasma diffusion coefficient and scalings derived from the short-time expansions of the velocity autocorrelation function and the memory function. Since the ions are weakly degenerate, we utilize a simple semiclassical correction to the classical dynamics. We find enhanced diffusion, relative to the purely classical calculation, which is more significant at smaller values of the Coulomb coupling parameter.