Fluid closures which mimic wave-praticle interactions in strong Langmuir turbulence

A new two-time-scale model of strong Langmuir turbulence has been constructed, using higher-moment fluid equations with dissipative closures designed to better simulate Vlasov theory predictions of linear wave properties, and to treat collisionless heating of particles by waves. Numerical solutions are carried out in a study of electron heating associated with collapse and burnout of a large-amplitude initial Langmuir wave and in a study of radiation-driven Langmuir turbulence interacting with ion-acoustic quasimodes in plasmas with ${\mathit{T}}_{\mathit{e}}$≊${\mathit{T}}_{\mathit{i}}$.