Anomalous ion loss due to low-frequency instabilities

Abstract

An ambipolarity formula for the cross-field flux of non-uniform plasma in the presence of low-frequency (ω ≪ ion gyrofrequency) electromagnetic fluctuations is presented. It is shown that, owing to ion polarization drift, the ions are pulled out by the diffusing electrons.

Dynamic transport simulation code including plasma rotation and radial electric field

“…By virtue of the poloidal momentum conservation, however, the reaction force on electrons F W eh should have the same magnitude of and the opposite direction to F W ih on ions. This implies that the transport induced by this force is the same for electrons and ions, that is, intrinsically ambipolar [28]. On the other hand, if the fluctuations do propagate radially, they may act as a perpendicular viscosity.…”

Stochastic magnetic field driven charge transport and zonal flow during magnetic reconnection

“…For low-frequency electromagnetic and electrostatic fluctuations ͑ Ӷ ci ͒, where ci is ion gyrofrequency, the total radial flux of ions ͑⌫ i T ͒ and electrons ͑⌫ e T ͒ can be written in the form, 13,15 …”

Nonambipolar Magnetic-Fluctuation-Induced Particle Transport and Plasma Flow in the MST Reversed-Field Pinch

“…(5a), not shown here, and are estimated to be smaller than hj k b r i=B for MST plasmas]. The first term is an ion polarization drift where V A is the Aflven speed [19], the second term is the charge flux generated only by magnetic fluctuations, and the last term is the classical charge flux arising from the radial flow due to the F B drift, where F is the viscous force within the magnetic surface perpendicular to B [11]. In the last term, is perpendicular viscosity coefficient and V EB ÿE r =B is a fluctuation-induced mean flow.…”