Collisionless cooling of perpendicular electron temperature in the thermal quench of a magnetized plasma
Year: 2024
Type: article
Abstract: Thermal quench of a nearly collisionless plasma against an isolated cooling boundary or region is an undesirable off-normal event in magnetic fusion experiments, but an ubiquitous process of cosmological importance in astrophysical plasmas. Parallel transport theory of ambipolar-constrained tail electron loss is known to predict rapid cooling of the parallel electron temperature [Formula: see text] although [Formula: see text] is difficult to diagnose in actual experiments. Instead direct experimental measurements can readily track the perpendicular electron temperature [Formula: see text] via electron cyclotron emission. The physics underlying the observed fast drop in [Formula: see text] requires a resolution. Here two collisionless mechanisms, dilutional cooling by infalling cold electrons and wave-particle interaction by two families of whistler instabilities, are shown to enable fast [Formula: see text] cooling that closely tracks the mostly collisionless crash of [Formula: see text] These findings motivate both experimental validation and reexamination of a broad class of plasma cooling problems in laboratory, space, and astrophysical settings.
Source: Scientific Reports
Authors: Yanzeng Zhang, Jun Li, Xian-Zhu Tang
Language: English
Subfield: Nuclear and High Energy Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $2,590
OpenAlex ID: W4403203718