Measurements of Canonical Helicity and Transport in a Gyrating Kink

Canonical flux tubes provide a topological perspective on reconnection and dynamo problems as the flux tubes do not break, even under non-ideal conditions, and the conservation of their helicity constrains the energy transfer between magnetic field and particles. We present measurements of canonical flux tubes, their helicity, and their helicity transport in a gyrating plasma kink. The helicity gauge is removed with general techniques valid even if only a limited section of the plasma is measured. Taylor diagrams evaluate these gauge removal techniques in terms of their effect on the normalized helicity density, and root mean square difference and lengths of the vector fields. Temporal asymmetries in the helicities confirm irreducible 3D fields in the kink. The transport of canonical helicity includes static injection through an applied voltage, a resistive sink term, and the change in reference fields corresponding to the change in helicity due to the motion of the flux rope in and out of the measurement volume.