Real sequence of qualitatively different plasma instabilities where each destabilizes the next
ORAL
Abstract
Laboratory experiments replicating astrophysical jets and solar corona loops operate in a regime spanning both magnetohydrodynamics and micro-scale physics beyond magnetohydrodynamics. These reproducible experiments involve large pulsed currents interacting with self and external magnetic fields to produce plasmas having the morphology and dynamics of astrophysical jets and solar corona loops. They typically evolve through a well-defined, resolved sequence which has been tracked using a wide variety of diagnostics including high-speed movie cameras, magnetic probes, spectroscopy, and X-ray scintillators. This sequence involves a range of spatial scales, temporal scales, morphologies, and distinct types of physics. A prime example is the astrophysical jet experiment where the following sequence is observed: (1) initial plasma breakdown, (2) formation of plasma jet which lengthens with time, (3) kink instability of plasma jet, (4) Rayleigh-Taylor instability of jet as a result of effective gravity produced by lateral acceleration from kink, (5) collisional Buneman instability as a result of choking of jet diameter by Rayleigh-Taylor instability, (6) production of X-ray bursts as a result of a large electric field associated with a collisional Buneman instability. A similar sequence is observed with the solar loop simulation. Key conclusions of these experimental observations are that the behavior cannot be described by a single model such as homogeneous turbulence. Instead, multiple temporal and spatial scales having different physical behaviors exist and interact with each other and finite spatial dimensions and finite time durations are important.
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Publication: Zhang, Yang and Pree, Seth and Bellan, Paul M. (2023) Generation of laboratory nanoflares from multiple braided plasma loops. Nature Astronomy, 7 (6). pp. 655-661<br><br>Zhou, Yi and Bellan, Paul M. (2023) Two-stream instability with a growth rate insensitive to collisions in a dissipative plasma jet. Physics of Plasmas, 30 (5). Art. No. 052101.<br><br>Bellan, Paul M. (2020) Caltech lab experiments and the insights they provide into solar corona phenomena. Journal of Geophysical Research. Space Physics, 125 (8). Art. No. e2020JA028139.<br><br>Zhang, Yang and Wongwaitayakornkul, Pakorn and Bellan, Paul M. (2020) Magnetic Rayleigh–Taylor Instability in an Experiment Simulating a Solar Loop. Astrophysical Journal Letters, 889 (2). Art. No. L32. doi:10.3847/2041-8213/ab6b2d.<br><br>Bellan, P. M. (2018) Experiments relevant to astrophysical jets. Journal of Plasma Physics, 84 (5). Art. No. 755840501. doi:10.1017/s002237781800079x.
