Dynamic mitigation of the tearing mode instability in a collisionless current sheet

Yan-Jun Gu,Sergei V Bulanov,Shigeo Kawata

doi:10.1038/s41598-021-91111-8

Abstract

Dynamic mitigation for the tearing mode instability in the current sheet in collisionless plasmas is demonstrated by applying a wobbling electron current beam. The initial small amplitude modulations imposed on the current sheet induce the electric current filamentation and the reconnection of the magnetic field lines. When the wobbling or oscillatory motion is added from the electron beam having a form of a thin layer moving along the current sheet, the perturbation phase is mixed and consequently the instability growth is saturated remarkably, like in the case of the feed-forward control.

Highlights

Dynamic mitigation for the tearing mode instability in the current sheet in collisionless plasmas is demonstrated by applying a wobbling electron current beam
The current sheet formation in high electric conductivity plasmas can be found in various situations: for example, magnetic reconnection via the current sheet formation and disruption is considered as a basic mechanism of solar flares[23], magnetic reconnection in the current sheets on the day side and in the tail of the earth magnetosphere plays the key role in the high energy charged particle a cceleration[24,25], and magnetic reconnection is crucially important in developing controlled magnetic confinement fusion[26,27]
The equilibrium state for the current sheet in a collisionless plasma based on the Harris solution presented in Ref.[31] is used as an initial configuration in the computer simulations whose results are discussed below

Summary

Introduction

Dynamic mitigation for the tearing mode instability in the current sheet in collisionless plasmas is demonstrated by applying a wobbling electron current beam. When the wobbling or oscillatory motion is added from the electron beam having a form of a thin layer moving along the current sheet, the perturbation phase is mixed and the instability growth is saturated remarkably, like in the case of the feed-forward control. The dynamic mitigation of plasma and fluid instability was proposed in Refs.[1,2,3,4] This approach uses the superimposing the phase-controlled plasma perturbations with the modulations growing due to the instability developing. With the particle-in-cell simulations, we demonstrate the dynamic mitigation of the tearing mode instability of the current sheet in collisionless plasma. Magnetic reconnection studies with high power laser interaction with matter is a fast developing research direction in so-called laboratory astrophysics[28,29,30]

Methods

Results

Conclusion