A Concept of Cross-Ferroic Plasma Turbulence.

S Inagaki,K Itoh,Y Nagashima,N Kasuya,M Lesur,T Mitsuzono,S.-I Itoh,Y Miwa,T Kobayashi,T Yamada,Y Kosuga,H Arakawa,M Sasaki,A Fujisawa

doi:10.1038/srep22189

Abstract

The variety of scalar and vector fields in laboratory and nature plasmas is formed by plasma turbulence. Drift-wave fluctuations, driven by density gradients in magnetized plasmas, are known to relax the density gradient while they can generate flows. On the other hand, the sheared flow in the direction of magnetic fields causes Kelvin-Helmholtz type instabilities, which mix particle and momentum. These different types of fluctuations coexist in laboratory and nature, so that the multiple mechanisms for structural formation exist in extremely non-equilibrium plasmas. Here we report the discovery of a new order in plasma turbulence, in which chained structure formation is realized by cross-interaction between inhomogeneities of scalar and vector fields. The concept of cross-ferroic turbulence is developed, and the causal relation in the multiple mechanisms behind structural formation is identified, by measuring the relaxation rate and dissipation power caused by the complex turbulence-driven flux.

Highlights

“Panta Rhei - everything flows and nothing lasts (Heraclitus)”, is true in our universe, because one structure that decays is generated after another
A homogeneous axial (z) magnetic field of B = 0.09 T confines plasma in the radial (r) direction
The primary origin in this chained structural formation is examined via the rate of dissipations[18,19]

Summary

Introduction

“Panta Rhei - everything flows and nothing lasts (Heraclitus)”, is true in our universe, because one structure that decays is generated after another. This boundary condition (source at one end and metal plate at the other end) induces a plasma flow and weak gradient of electron pressure in the direction of the magnetic field, and determines the axial mode structure of the drift wave.

Results

Conclusion