Broadening and Self-Absorption of the Resonance Lines of H-like Light Ions in Laser-Produced Plasmas

Spectra emitted by various ions in laser-produced plasmas have been observed with spatial resolution in the soft-X-ray region. The profiles of the first three Lyman lines Lα, Lβ and Lγ of Be IV, B V, C VI and the Lα linos of N VII and 0 VIII, that appear strongly broadened and asymmetrically self-absorbed, have been analysed in detail. A model for the expanding plasma has been developed that accounts for the different broadening mechanisms and their effects on the radiation trapping in a moving plasma. The extent of the different contributions to the broadening along the isoelectronic sequence has been analysed. The potentiality of such detailed spectroscopic observations for determining basic plasma parameters has been established over a wide range of conditions. Comparison with other theoretical treatments of radiation transfer effects in moving plasmas shows good agreement. © 1978 Società Italiana di Fisica.