Exact Nonlinear Plasma Oscillations
Abstract
The problem of a onedimensional stationary nonlinear electrostatic wave in a plasma free from interparticle collisions is solved exactly by elementary means. It is demonstrated that, by adding appropriate numbers of particles trapped in the potentialenergy troughs, essentially arbitrary traveling wave solutions can be constructed. When one passes to the limit of smallamplitude waves it turns out that the distribution function does not possess an expansion whose first term is linear in the amplitude, as is conventionally assumed. This disparity is associated with the trapped particles. It is possible, however, to salvage the usual linearized theory by admitting singular distribution functions. These, of course, do not exhibit Landau damping, which is associated with the restriction to wellbehaved distribution functions. The possible existence of such waves in an actual plasma will depend on factors ignored in this paper, as in most previous works, namely interparticle collisions, and the stability of the solutions against various types of perturbations.
 Publication:

Physical Review
 Pub Date:
 November 1957
 DOI:
 10.1103/PhysRev.108.546
 Bibcode:
 1957PhRv..108..546B