Kinetic theory of the evolution of collective plasma excitations in an external electric field

The kinetic theory of a plasma is developed on the basis of a normal mode analysis-In the absence of any external field, the system approaches a ‘plasmadynamical (PD) state’, described by fourteen amplitudes of the PD modes. The corresponding eigenvalues and eigenvectors are constructed explicitly. When an external time-dependent electric field is switched on, transitions between these modes determine the evolution of the plasma. Assuming that a PD regime is valid, the kinetic equations reduce to a set of equations describing parametric effects and nonlinear mode-mode couplings. A new source term, arising from the interference between collisions and external field, also appears. Some qualitative implications are discussed.