Title

Laboratory Sources Of Turbulent Plasma: A Unique MHD Plasma Wind Tunnel

Document Type

Article

Publication Date

12-1-2014

Published In

Plasma Sources Science and Technology

Abstract

Turbulence has been studied in laboratory plasmas for decades. Magnetic and electrostatic turbulence fluctuations have been implicated in degraded confinement in fusion devices so understanding turbulent transport is critical for those devices. The externally applied magnetic field in most laboratory plasmas has a strong effect on the character of the turbulence (particularly parallel and perpendicular to the applied field). A new turbulent plasma source is described with several unique features. First, the magnetohydrodynamic (MHD) wind tunnel configuration has no applied magnetic field and has no net axial magnetic flux. Second, the plasma flow speed is on the order of the local sound speed (M = 1), so flow energy is comparable to thermal energy. Third, the plasma β (ratio of thermal to magnetic pressure) is of order unity so thermal energy is comparable to magnetic energy. We will review sources of magnetic turbulence in laboratory plasmas and discuss the main analytical tools used in the study of plasma turbulence. Some initial results from the MHD plasma wind tunnel will be presented.