Extreme ultra-violet burst, particle heating, and whistler wave emission in fast magnetic reconnection induced by kink-driven Rayleigh-Taylor instability

Abstract

A spatially localized energetic extreme ultra-violet (EUV) burst is imaged at the presumed position of fast magnetic reconnection in a plasma jet produced by a coaxial helicity injection source; this EUV burst indicates strong localized electron heating. A circularly polarized high frequency magnetic field perturbation is simultaneously observed at some distance from the reconnection region indicating that the reconnection emits whistler waves and that Hall dynamics likely governs the reconnection. Spectroscopic measurement shows simultaneous fast ion heating. The electron heating is consistent with Ohmic dissipation, while the ion heating is consistent with ion trajectories becoming stochastic.

Laboratory Measurement of Large‐Amplitude Whistler Pulses Generated by Fast Magnetic Reconnection

“…Since the current and the background magnetic field are antiparallel in the axial direction, the jet kinks in a left-handed sense (Hsu & Bellan, 2003). The apparatus is described in detail in Hsu and Bellan (2002), Moser and Bellan (2012), and Chai et al (2016), and a 3-D magnetohydrodynamic simulation of the experiment is described in Zhai et al (2014). During the fast lateral acceleration of the growing helical perturbation, a secondary Rayleigh-Taylor instability develops on the trailing edge of the laterally moving jet.…”

“…This detachment necessarily involves a magnetic reconnection event due to the changing magnetic topology. Previous measurements of detachment events (Chai et al, 2016;Marshall et al, 2018) identified simultaneous emission of extreme ultraviolet light, X-rays, current disruptions, and broadband magnetic oscillations near the reconnection site. These reconnection events are not as reproducible as the global jet morphology, and occur for ∼60% of shots taken with a particular set of initial conditions.…”

“…This paper reports the first far-field (>50 ion skin depths) wave vector measurements of large-amplitude whistler wave pulses (0.001 ≤ B∕B ≤ 0.05) generated by impulsive magnetic reconnection events. The wave pulses are measured in the Caltech jet experiment (Chai et al, 2016;Hsu & Bellan, 2002) with a new multicluster . B-probe mimicking the tetrahedral formations of the Cluster (Dunlop et al, 2001;Eastwood et al, 2006;Graham et al, 2015) and Magnetospheric Multiscale Mission (MMS) spacecraft (Breuillard et al, 2016;Cao et al, 2017;Gershman et al, 2017;Wilder et al, 2016).…”

A hybrid Rayleigh-Taylor-current-driven coupled instability in a magnetohydrodynamically collimated cylindrical plasma with lateral gravity

“…The RT instability quickly erodes and breaks the jet structure, leading to fast magnetic reconnection. 20,24 Hydrogen plasmas are found to develop kink instability in a very similar manner; but no distinct RT instability has been observed for hydrogen jets with g $ 10 10 m/s 2 ; RT instabilities with axial wavelength k z ¼ 3 À 5 cm are observed only in some rare shots with strong lateral acceleration g ¼ 10 11 À 3 Â 10 11 m/s 2 . We name the two cases as type I and type II hydrogen jets, respectively.…”

“…There is jq 0 rÁ dU=ðcdqÞj $ jq 0 dU r =ðcRdqÞj $ 0:1 ( 1. Here, c $ 3 Â 10 6 s À1 , R¼3cm, dq $ q 0 based on recent Stark broadening spectroscopic measurement, 24 and dU r $ 10km/s estimated from Fig. 3 of Ref.…”