Cooling flow regime of a plasma thermal quench

Abstract

A large class of Laboratory, Space, and Astrophysical plasmas is nearly collisionless. When a localized energy or particle sink, for example, in the form of a radiative cooling spot or a black hole, is introduced into such a plasma, it can trigger a plasma thermal collapse, also known as a thermal quench in tokamak fusion. Here we show that the electron thermal conduction in such a nearly collisionless plasma follows the convective energy transport scaling in itself or in its spatial gradient, due to the constraint of ambipolar transport. As the result, a robust cooling flow aggregates mass toward the cooling spot and the thermal collapse of the surrounding plasma takes the form of four propagating fronts that originate from the radiative cooling spot, along the magnetic field line in a magnetized plasma. The slowest one, which is responsible for deep cooling, is a shock front.

References in corpus (4)

• The Quiescent Intracluster Medium in the Core of the Perseus Cluster
• Turbulent Heating in Galaxy Clusters Brightest in X-rays
• Suppression of electron thermal conduction by whistler turbulence in a sustained thermal gradient
• Regulation of thermal conductivity in hot galaxy clusters by MHD turbulence

Cited by in corpus (6)

• Electromagnetic turbulence simulation of tokamak edge plasma dynamics and divertor heat load during thermal quench
• Staged cooling of a fusion-grade plasma in a tokamak thermal quench
• On the collisional damping of plasma velocity space instabilities
• Electron heat flux and propagating fronts in plasma thermal quench via ambipolar transport
• Collisionless cooling of perpendicular electron temperature in the thermal quench of a magnetized plasma
• Similarity for downscaled kinetic simulations of electrostatic plasmas: reconciling the large system size with small Debye length