Student Excellence Award Finalist: Evidence of Stabilization in Current-Driven Plasma Jets

We report on the first direct visualization detailing the dynamic stabilization of current-driven dense plasma jets. Videography of backlit refractometry (10 MHz, 256 frames) indicates the presence of long wavelength magnetohydrodynamic kink instabilities that stabilize over time as a quasi-steady axial-directed flow surrounding a central pinch is formed. A linear stability analysis confirms that in the presence of the surrounding flow, the pinch is most prone to the m = 1 kink mode, but that even this mode is damped at high current regimes due to the increased plasma jet velocity. The results point to the possibility for an arbitrarily stable plasma column over timescales for which a surrounding flow can be maintained.