Magnetic Reconnection in the Spheromak: Physics and Consequences

Energy confinement and magnetic field generation in the SSPX spheromak

“…This result is compared to NIMROD simulation [17] (Figure 8b) and we find that after formation the two results are in quantitative agreement [18]. For extended formation discharges, we are able to plot the calculated FA against λ gun for many discharges and find that they also fall along the line predicted from NIMROD ( Figure 9).…”

Achieving high flux amplification in a gun-driven, flux-core spheromak

“…In experiments it is seen that the magnitude of the gun voltage increases with λ g [14,21]. The voltage spikes generated by the reconnection events, seen clearly in simulations [12], have higher amplitude and a faster repetition rate at the higher λ g in both simulation…”

“…1b Experimental results to date typically achieve flux amplifications of about 3-4, although up to 6 has been obtained. Experimental results are compared with resistive MHD simulations [14] in Fig. 2.…”

“…[13], with significant consequences for energy confinement which may require separation of the current drive and confinement phases in a reactor [14]. The spheromak current and flux will decay during the confinement phase as the dynamo is turned off, so it will likely be necessary to rebuild them periodically using a dynamo pulse.…”

An ion Doppler spectrometer instrument for ion temperature and flow measurements on SSPX

“…1 This makes ion temperature an important measurement. It has also been shown that sub-Alfvénic flow velocities have the potential to stabilize drift wave turbulence and improve energy confinement in spheromaks, 2 and hence warrants a measurement of flow inside sustained spheromak plasma experiment ͑SSPX͒.…”