Collapse of Langmuir solitons in inhomogeneous plasmas

TL;DR

This paper investigates how Langmuir solitons behave in inhomogeneous plasmas, showing they accelerate, emit cavities, and eventually collapse as the density gradient increases, using numerical simulations of Zakharov equations.

Contribution

It provides a numerical analysis of Langmuir soliton dynamics in inhomogeneous plasmas, including the collapse mechanism and threshold estimation.

Findings

Solitons accelerate toward low-density regions.

Cavities are emitted during soliton acceleration.

Solitons collapse beyond a certain density gradient threshold.

Abstract

Propagation of Langmuir solitons in inhomogeneous plasmas is investigated numerically. Through numerical simulation solving Zakharov equations, the solitons are accelerated toward the low density side. As a consequence, isolated cavities moving at ion sound velocities are emitted. When the acceleration is further increased, solitons collapse and the cavities separate into two lumps released at ion sound velocities. The threshold is estimated by an analogy between the soliton and a particle overcoming the self-generated potential well.