Effect of Wave Collapse on Lyman and Balmer lines

The nonlinear coupling of Langmuir, ion sound and electromagnetic waves can create wave collapse conditions in a plasma, and modify the line shapes emitted by hydrogen atoms. Such conditions may appear in the presence of a strong source of energy, and create numerous regions where wave packets localize and the plasma density is decreased. We use a model of envelope solitons for the electric field acting on the emitter, and calculate the dipole autocorrelation function and the line shape with a numerical simulation. We investigate the role of the frequency of wave packets, and propose an approach retaining a dispersion relation ω(k). (paper)