Comparative study of the loss cone-driven instabilities in the low solar corona

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

DOI:https://doi.org/10.1086/162006· OSTI ID:6796310

Sharma, R R; Vlahos, L

A comparative study of the loss cone--driven instabilities in the low solar corona is undertaken. The instailities considered are the electron maser, the whistler, and the electrostatic upper hybrid. We show that the first-harmonic extraordinary mode of the electron cyclotron maser instability is the fastest growing mode for strongly magnetized plasma (..omega../sub e//..cap omega../sub e/<0.35, where ..omega../sub e/ is the plasma frequency, and ..cap omega../sub e/ is the cyclotron frequency). For 0.35<..omega../sub e/..cap omega../sub e/<1.0, the first-harmonic ordinary mode of the electron cyclotron maser instability dominates the emission. For ..omega../sub e//..cap omega../sub e/>1.0, no direct electromagnetic radiation is expected since other instabilities, which do not escape directly, saturate the electron cyclotron maser (the whistler or the electrostatic upper hybrid waves). We also show that the second-harmonic electron cyclotron maser emission never grows to an appreciable level. Thus, we suggest that the electron cyclotron maser instability can be the explanation for intense radio bursts only when the first harmonic escapes from the low corona. We propose a possible explanation for the escape of the first harmonic from a flaring loop.

• Research Organization: Astronomy Program, University of Maryland
• OSTI ID: 6796310
• Journal Information: Astrophys. J.; (United States), Journal Name: Astrophys. J.; (United States) Vol. 280:1; ISSN ASJOA
• Country of Publication: United States
• Language: English

Related Subjects

640104* -- Astrophysics &amp; Cosmology-- Solar Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
AMPLIFIERS
ATMOSPHERES
BREMSSTRAHLUNG
CYCLOTRON HARMONICS
CYCLOTRON RADIATION
DISPERSION RELATIONS
ELECTROMAGNETIC RADIATION
ELECTRONIC EQUIPMENT
ELECTRONS
ELEMENTARY PARTICLES
EMISSION SPECTRA
EQUIPMENT
FERMIONS
HARMONICS
INSTABILITY
LEPTONS
LOSS CONE
LOSS CONE INSTABILITY
MASERS
MICROWAVE AMPLIFIERS
MICROWAVE EQUIPMENT
NOISE
OSCILLATIONS
PLASMA
PLASMA INSTABILITY
PLASMA MICROINSTABILITIES
POLARIZATION
RADIATIONS
RADIO NOISE
RADIOWAVE RADIATION
SOLAR ACTIVITY
SOLAR CORONA
SOLAR FLARES
SOLAR RADIO BURSTS
SPECTRA
STELLAR ATMOSPHERES
STELLAR CORONAE
WAVE PROPAGATION
WHISTLERS