Comparative Study on Ion-Dynamics for Broadening of Lyman Lines in Dense Hydrogen Plasmas

Broadening of spectral lines by a plasma surrounding can be used for plasma diagnostics. Full hydrogen Lyman line profiles are calculated with a quantum‐statistical approach. The effects of plasma electrons and ions on the emitter states are considered separately. The influence of electrons is considered in a dynamically screened Born approximation (collision approximation). For the ions, we apply the quasi‐static approximation and two different approaches to account for ion‐dynamics, namely, the model microfield method (MMM) and the frequency fluctuation model (FFM). We compare resulting widths of Lyman lines in the temperature range T = 104 to 107 K and the free electron density range ne = 1023 to 1026 m–3. For Lα, the error made by neglecting ion‐dynamics increases with increasing temperature and decreasing density, and is at least –15%. Due to the double peaked structure of Lβ the situation is less systematic. However, a large region exists, where ion‐dynamics does not affect the line shape of Lβ. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)