Plasma convection in the poloidal limiter shadow of a tokamak

Abstract

Plasma flow in the poloidal limiter shadow of a tokamak is examined. It is shown that, as a result of contact with a limiter, a large poloidal electric field is created in the plasma. Plasma drift in this field can be considered as anomalous diffusion. The characteristic dimension of the change in plasma density is found to be of the order of the ion cyclotron radius calculated for a poloidal magnetic field. The plasma flow is non-ambipolar and the electric current closes its circuit via the limiter. The results obtained are confirmed by experiments on various tokamaks.

Reduction of the turbulent blob transport in the scrape-off layer by a resonant magnetic perturbation in TEXTOR

“…Illustrative examples can be found in Fig. 6 for a higher q(a) In this section, we first compare our experimental results with predictions on blob formation and dynamics by theories based on the interchange instability [22][23][24]. The theory proposes that the blob structure develops on the base of a turbulent eddy inside (near) the separatrix, and is then driven radially outwards by the curvature drift on a dipolar vorticity.…”

Transport of meso-scale structures in tokamak edge plasmas

“…As a result, the dissipation term in the limit of small deviation of electrostatic potential from its equilibrium value | φ |< 1 can be written as follows (see for example Refs. [36,39,40] and [22,23])…”

Effect of parallel currents on drift-interchange turbulence: Comparison of simulation and experiment

“…For example, when the end plates are conducting, a sheath allows, but also limits, the parallel current to the end plates and influences the linear stability and related turbulence. [14][15][16][17][18] Recently, this issue was studied on CSDX 19 by changing the composition of the end plates in order to modify the axial BC. The characteristics of the plasma turbulence were measured for both an insulating boundary a) email: dippolito@lodestar.com.…”