Turbulent resistive heating of solar coronal arches

Journal Article · Wed Jun 15 00:00:00 EDT 1983 · Astrophys. J.; (United States)

DOI:https://doi.org/10.1086/161078· OSTI ID:5668384

Benford, G

Field-aligned currents in coronal arches can heat the plasma through instability if the electron drift velocity is large enough. We consider the heating as a time-dependent problem in a plasma cylinder, including heating rates for ions and electrons, longitudinal conduction and convection, radiation, and cross-field transport, all using both Coulomb and turbulent effects. Electron drift velocity is held constant, resembling an arch with high inductance. The electrostatic ion cyclotron instability proves the dominant effect at all times, starting from an initially isothermal plasma at T = 10 eV. Ion acoustic modes never become unstable, since T/sub e//T/sub i/ never exceeds 3. Rapid heating to temperatures of 100--1000 eV occurs, after which a slow ''percolation'' sets in, with turbulence switching on and off rapidly, keeping the plasma temperature in the approx.100 eV range. This steady tradeoff between weak microturbulence and macroscopic loss processes determines the long time heating level. Turbulence is described with a resonantly broadened saturation model which enjoys some experimental support. Radiation losses are never important. High density arches heat more slowly (approx.10 s). Finite plasma pressure effects and turbulent cross-field transport have little influence on the long term temperature. Cases with a turbulent Ohm's law (low inductance case) also yield strong heating rates. Despite its intrinsic unsteady behavior, resistive heating seems capable of providing efficient arch heating.

• Research Organization: Physics Department, University of California, Irvine
• OSTI ID: 5668384
• Journal Information: Astrophys. J.; (United States), Vol. 269:2
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
SOLAR CORONA
HEATING
PLASMA
CONVECTION
ELECTRIC FIELDS
ELECTRONS
IONS
MAGNETIC FIELDS
MAGNETOHYDRODYNAMICS
TURBULENCE
CHARGED PARTICLES
ELEMENTARY PARTICLES
FERMIONS
FLUID MECHANICS
HYDRODYNAMICS
LEPTONS
MECHANICS
640104* - Astrophysics & Cosmology- Solar Phenomena