Non-modal analysis of the diocotron instability. Plane geometry

TL;DR

This paper investigates the linear evolution of the diocotron instability in a plane electron strip, highlighting the role of initial density perturbations and the transition to phase-locking of normal modes.

Contribution

It provides a non-modal analysis of the diocotron instability, emphasizing the impact of initial conditions and continuous spectrum effects on the linear evolution.

Findings

Initial perturbations influence the instability development.

Linear evolution converges to phase-locking of normal modes.

Kelvin's shearing modes method elucidates the process.

Abstract

The comprehensive investigation of the temporal evolution of the diocotron instability of the plane electron strip on the linear stage of its development is performed. By using the Kelvin's method of the shearing modes we elucidate the role of the initial perturbations of the electron density, which is connected with problem of the continuous spectrum. The linear non-modal evolution process, detected by the solution of the initial value problem, leads towards convergence to the phase-locking configuration of the mutually growing normal modes.