Dynamic mitigation of two-stream instability in plasma

TL;DR

This paper presents a phase control-based dynamic mitigation mechanism for two-stream instability in plasmas, demonstrating effective suppression of instabilities and smoothing of non-uniformities through active perturbation management.

Contribution

It introduces a novel phase control method for actively mitigating two-stream instability in plasma, building on previous theoretical proposals.

Findings

Effective suppression of two-stream instability demonstrated

Perturbation amplitudes can be controlled via phase management

Non-uniformities in plasma are smoothed by the mitigation method

Abstract

A dynamic mitigation mechanism of the two-stream instability is discussed based on a phase control for plasma and fluid instabilities. The basic idea for the dynamic mitigation mechanism by the phase control was proposed in the paper [Phys. Plasmas 19, 024503(2012)]. The mitigation method is applied to the two-stream instability in this paper. In general, instabilities appear from the perturbations, and normally the perturbation phase is unknown. Therefore, the instability growth rate is discussed in fluids and plasmas. However, if the perturbation phase is known, the instability growth can be controlled by a superimposition of perturbations imposed actively. For instance, a perturbed driver induces a perturbation to fluids or plasmas; if the perturbation induced by the perturbed driver is oscillated actively by the driver oscillation, the perturbation phase is known and the perturbation amplitude can be controlled, like a feedforward control. The application result shown in this paper demonstrates that the dynamic mitigation mechanism works well to smooth the non-uniformities and mitigate the instabilities in plasmas.