title: Dispersion in a thermal plasma including arbitrary degeneracy and quantum recoil.
abstract: The longitudinal response function for a thermal electron gas is calculated including two quantum effects exactly, degeneracy, and the quantum recoil. The Fermi-Dirac distribution is expanded in powers of a parameter that is small in the nondegenerate limit and the response function is evaluated in terms of the conventional plasma dispersion function to arbitrary order in this parameter. The infinite sum is performed in terms of polylogarithms in the long-wavelength and quasistatic limits, giving results that apply for arbitrary degeneracy. The results are applied to the dispersion relations for Langmuir waves and to screening, reproducing known results in the nondegenerate and completely degenerate limits, and generalizing them to arbitrary degeneracy.
authors.affiliation: School of Physics, University of Sydney, New South Wales 2006, Australia.
authors.forename: D B
authors.initials: DB
authors.lastname: Melrose
authors.forename: A
authors.initials: A
authors.lastname: Mushtaq