Hall Reconnection in MST

Previous measurements in MST have established that two-fluid Hall effects produce a dynamo effect (the radial transport of parallel current), and are thereby important in evaluating the macroscopic effects of reconnection. This was established by measuring the \textit{nonlinear} Hall term in Ohm’s law ($<\delta j \times \delta B>$, where $< >$ denotes a magnetic surface average). We report here measurements of the \textit{linear} Hall term ($\delta j \times B$) as a more direct indicator of the role of Hall effects in reconnection dynamics. The linear Hall term is compared with the other measured terms in Ohm’s law to assess its influence on the structure of the reconnected field and the reconnection current. Probes are inserted to the reversal surface to measure the radial structure of reconnection associated with modes with poloidal mode number $m = 0$.