Plasma-Screening Effects upon Atomic Hydrogen Photoabsorption

We present oscillator strengths and photoionization cross-sections of an electron bound by a Debye potential, V(r) = - (1 Ir) exp (-rID), for a range of Debye lengths D. All photoionization cross-sections vanish at threshold, and near series limits the strengths of bound-bound transitions fall well below hydrogenic values. We discuss the relevance of these calculations to the interpretation of Balmer line spectra in stellar atmospheres. We also note the effects of plasma screening on line blanketing and on bound-free opacities. Subject headings: plasmas - transition probabilities - white dwarf stars