Time Resolved Measurements of Electron Acceleration in Pulsed Power Driven Magnetic Reconnection*

Magnetic reconnection is a relaxation mechanism through which energy stored in magnetic flux is dissipated, leading to plasma heating and acceleration, and the generation of fast particles. Historically, particle acceleration has been a key signature of reconnection in astrophysical observations, however it is typically not diagnosed in laboratory experiments.

In this talk, we present results from a recently developed, pulsed power driven reconnection platform [1, 2] in which we observed electron acceleration by the reconnecting electric field. The acceleration was localised to the reconnection layer and was bursty in time. The energy of the fast electrons (> 2 keV) exceeded the temperature of the plasma (< 100 eV) by over an order of magnitude.

To diagnose electron acceleration, metal foils were placed in the paths of fast electrons. Atomic transitions were collisionally excited in the foils to produce characteristic X-Ray spectra. This emission was diagnosed using pinhole imaging and X-Ray spectroscopy. Time resolved measurements were made using fast silicon photodiode detectors.

[1] L. G. Suttle et al. PRL 2016             [2] J. D. Hare et al. PRL 2017