Oscillator strengths in dense hydrogen plasma-no 'transparency window'

Energy levels, oscillator strengths and photoionisation cross sections of an electron in the Debye-Huckel and the cut-off Coulomb potential are obtained by numerically solving the Schrodinger equation. The shifted continuum of bound-free transitions takes over the oscillator strength of vanishing bound-bound transitions, the averaged oscillator strength remains very close to that of the unscreened Coulomb potential. Calculated emission spectra with broadening demonstrate that there is no 'transparency window' around threshold whose existence has been claimed by other authors. The results given for the Lyman series can be easily generalised to the Balmer and other series.