Measurements of the Canonical Helicity of a Gyrating Kink.

Conversions between magnetic and kinetic energy occur over a range of plasma scales in astrophysical and solar dynamos and reconnection in the solar corona and the laboratory. Canonical flux tubes reconcile all plasma regimes with concepts of twists, writhes, and linkages. We present measurements of canonical flux tubes, their helicity, and their helicity transport in a gyrating plasma kink.

Pulsating Magnetic Reconnection Driven by Three-Dimensional Flux-Rope Interactions.

The dynamics of magnetic reconnection is investigated in a laboratory experiment consisting of two magnetic flux ropes, with currents slightly above the threshold for the kink instability. The evolution features periodic bursts of magnetic reconnection. To diagnose this complex evolution, volumetric three-dimensional data were acquired for both the magnetic and electric fields, allowing key field-line mapping quantities to be directly evaluated for the first time with experimental data.

Investigating the momentum balance of a plasma pinch: an air-side stereoscopic imaging system for locating probes.

The momentum balance of a plasma pinch in the Reconnection Scaling Experiment (RSX) is examined in three dimensions using several repositionable, insertable probes. A new camera-based system described here triangulates the locations of the probe tips so that their measurements are spatially registered. The optical system locates probes to within ±1.

Superdiffusion of two-dimensional Yukawa liquids due to a perpendicular magnetic field.

Stochastic transport of a two-dimensional (2D) dusty plasma liquid with a perpendicular magnetic field is studied. Superdiffusion is found to occur especially at higher magnetic fields with β of order unity. Here, β = ω(c)/ω(pd) is the ratio of the cyclotron and plasma frequencies for dust particles.

A compact fast ionization gauge for in situ measurement of high-density neutral flow dynamics.

A compact ionization gauge has been developed to carry out in situ measurements of high density (10(20)-10(22) m(-3)) neutral gas flow dynamics with high temporal and spatial resolution. Key design aspects are discussed including gauge sensitivity and time response scaling with decreased probe dimensions, high-pressure operation, improved driver circuit bandwidth, and techniques for constructing a miniaturized probe head. Gas adsorption was discovered to significantly alter emission current and gauge sensitivity over timescales of several seconds.