Momentum Transport and Blob Generation in the Large Plasma Device

Intermittent turbulence and turbulent transport via blob-filaments are widely observed in the edges of magnetized plasma experiments and shear flow suppression of turbulent transport has previously been studied in the Large Plasma Device (LAPD) [1]. Recent simulations have explored how the parallel variation of flows can significantly contribute to the reduction of blob-filament radial velocity [2]. Recent LAPD experiments with the new LaB6 cathode produce plasmas with steep edge density gradients, reduced radially-propagating blob activity, and azimuthal rotation of the plasma column without the use of a limiter or biasing. We will present recent experiments exploring the interplay between plasma flows and currents with the momentum transport and generation of blobs in the LAPD.

[1] D. A. Schaffner, T. A. Carter, G. D. Rossi, D. S. Guice, J. E. Maggs, S. Vincena, and B. Friedman, Turbulence and Transport Suppression Scaling with Flow Shear on the Large Plasma Device, Physics of Plasmas 20, 055907 (2013).

[2] J. R. Myra, S. Ku, D. A. Russell, J. Cheng, I. Keramidas Charidakos, S. E. Parker, R. M. Churchill, and C. S. Chang, Reduction of Blob-Filament Radial Propagation by Parallel Variation of Flows: Analysis of a Gyrokinetic Simulation, Physics of Plasmas 27, 082309 (2020).