Experimental study of Ion Energization During Guide Field Reconnection in the Magnetic Reconnection Experiment (MRX)

Magnetic Reconnection is a fundamental plasma process in which magnetic energy is converted to particle energy during a global change in magnetic topology. Most reconnection events in space and fusion plasmas occur in the presence of a finite magnetic field component perpendicular to the reconnection plane, known as a guide field. A new campaign on the Magnetic Reconnection eXperiment (MRX) at Princeton Plasma Physics Laboratory (PPPL) aims to elucidate the role of the guide field in the conversion of magnetic energy to particle energy of ions. A new ion Doppler diagnostic [Goodman et al. RSI (2021)], utilizing tomographic inversion of line-of-sight emission measurements, is used for the first time on MRX to measure the ion temperature and flows parallel to the guide field. Existing Ion Doppler Spectroscopy Probes (IDSP) are used to calibrate ion temperature measurements, while Mach and Langmuir probes are used for floating potential measurements and flows in the reconnection plane. Data  is collected across the reconnection region for four guide field strengths, ranging from zero to 2.1 times the strength of the reconnecting field and used to quantify the changes in ion energization. Detailed results will be presented, discussed, and compared with relevant theoretical predictions.