Radio-frequency heating of the coronal plasma during flares

Journal Article · Sun Jul 01 04:00:00 EDT 1984 · Astrophys. J.; (United States)

DOI:https://doi.org/10.1086/162204· OSTI ID:6302273

Melrose, D B; Dulk, G A

We develop a model for the radio-frequency (RF) heating of soft X-ray emitting plasma in solar flares due to absorption of amplified cyclotron radiation. The radiation, carrying approx.10/sup 27/ to approx.10/sup 30/ egers s/sup -1/, is generated through masser emission following partial precipitation of electrons in one or more flaring loops. The maser operates in a large number of small regions, each producing an ''elementary burst'' (EB) of short duration. This radiation propagates either directly or after reflection to the second-harmonic absorption layer, where it is absorbed by thermal electrons. The properties of EBs and the heating of the electrons in the absorption layer are discussed in detail. RF heating and evaporation models for the production of soft X-ray emitting plasma are compared. Properties of the RF heating model that explain observed features are energy transport across field lines, rapid heating (in approx.1 s) of coronal plasma to roughly-equal3 x 10/sup 7/ K, and instigation of turbulent velocities up to the ion sound speed.

• Research Organization: School of Physics, University of Sydney, Australia
• OSTI ID: 6302273
• Journal Information: Astrophys. J.; (United States), Journal Name: Astrophys. J.; (United States) Vol. 282:1; ISSN ASJOA
• Country of Publication: United States
• Language: English

Related Subjects

640104* -- Astrophysics & Cosmology-- Solar Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ABSORPTION
AMPLIFIERS
ATMOSPHERES
BREMSSTRAHLUNG
COLLISIONS
CYCLOTRON RADIATION
ELECTROMAGNETIC RADIATION
ELECTRON COLLISIONS
ELECTRONIC EQUIPMENT
ELECTRONS
ELEMENTARY PARTICLES
EMISSION
EQUIPMENT
FERMIONS
HEATING
IONIZING RADIATIONS
LEPTONS
MASERS
MICROWAVE AMPLIFIERS
MICROWAVE EQUIPMENT
PLASMA
PLASMA HEATING
RADIATIONS
RADIOWAVE RADIATION
SOLAR ACTIVITY
SOLAR CORONA
SOLAR ELECTRONS
SOLAR FLARES
SOLAR PARTICLES
SOLAR RADIATION
SOLAR RADIOWAVE RADIATION
STELLAR ATMOSPHERES
STELLAR CORONAE
STELLAR RADIATION
TURBULENCE
X RADIATION