Effect of nonlinear wave collapse on line shapes in a plasma
1 Physique des Interactions Ioniques et Moléculaires, UMR 7345, AMU-CNRS - Marseille, France
2 PRIMALAB, Sciences of matter faculty, University of Batna 1 - Batna, Algeria
Received: 8 February 2016
Accepted: 29 April 2016
The nonlinear interaction of waves can change the structural and radiative properties of plasmas. We describe the main features of a fully ionized unmagnetized plasma affected by strong Langmuir turbulence characterized by nonlinear wave collapse, and propose a simple model for evaluating the changes expected on a hydrogen line shape affected by such conditions. Our model is based on a stochastic renewal model using an exponential waiting time distribution and a half-normal probability density function for the electric-field magnitude of the turbulent wave packet. The first results obtained with a simulation calculation of the hydrogen line show that strong Langmuir turbulence can provide an additional broadening to a Stark profile.
PACS: 32.70.Jz – Line shapes, widths, and shifts / 52.35.Mw – Nonlinear phenomena: waves, wave propagation, and other interactions (including parametric effects, mode coupling, ponderomotive effects, etc.)
© EPLA, 2016