Results from Experiments on Multiple Interacting Magnetized Electron Temperature Filaments

Steep thermal gradients in a magnetized plasma can induce a variety of spontaneous low frequency excitations such as thermal waves, drift-Alfven waves, and convective cells. We present results from experiments with multiple heat sources in close proximity. The setup consists of three biased probe-mounted CeB₆ crystal cathodes that inject low energy electrons along a strong magnetic field into a pre-existing cold afterglow plasma forming three electron temperature filaments. A triangular spatial pattern is chosen for the thermal sources and multiple axial and transverse probe measurements allow for determination of the cross-field mode patterns and axial filament length. When the three sources are activated and placed within a few collisionless electron skin depths a complex wave pattern emerges due to interference of the various wave modes on each filament, thus leading to enhanced cross-field transport from chaotic mixing (E×B). Detailed eigenmode analysis of the configuration and comparison with nonlinear 2-fluid and gyrokinetic simulations will be reported.