Electromagnetic instabilities driven by unequal proton beams in the solar wind

Journal Article · Tue Jun 01 04:00:00 EDT 1976 · J. Geophys. Res.; (United States)

DOI:https://doi.org/10.1029/JA081i016p02743· OSTI ID:7356391

Montgomery, M D; Gary, S P; Feldman, W C; Forslund, D W

The linear dispersion relation for electromagnetic waves is investigated for homogeneous plasmas normally found in the solar wind near 1 AU, including a secondary proton beam of varying strength and drift speed parallel to the ambient magnetic field. Three instabilities are found when the drift speed of the beam approaches the Alfven speed C/subA/: (1) field-aigned magnetosonic, (2) oblique magnetosonic, and (3) oblique Alfven modes. Linear growth rates as a function of ..beta..=8..pi..nT/subp//B/sub 0/ /sup 2/, drift speed, T/sube//T/subp/, proton and electron temperature anisotropies, and electron heat flux have been studied. Results show that beam-driven magnetosonic and Alfven waves are likely to be important in the solar wind if the fraction of protons in the beam exceeds 5% and the drift speed exceeds approx.0.8C/subA/ when ..beta..approximately-less-than0.1 (or approx.1.5C/subA/ when ..beta..approximately-greater-than0.4). (AIP)

• Research Organization: University of California, Los Alamos Scientific Laboratory, Los Alamos, New Mexico 87545
• OSTI ID: 7356391
• Journal Information: J. Geophys. Res.; (United States), Journal Name: J. Geophys. Res.; (United States) Vol. 81:16; ISSN JGREA
• Country of Publication: United States
• Language: English

Related Subjects

640104* -- Astrophysics & Cosmology-- Solar Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
BEAMS
DISPERSION RELATIONS
HEATING
IMP SATELLITES
INSTABILITY
INSTABILITY GROWTH RATES
NUCLEON BEAMS
PARTICLE BEAMS
PLASMA HEATING
PLASMA INSTABILITY
PROTON BEAMS
PROTON TEMPERATURE
SATELLITES
SOLAR ACTIVITY
SOLAR WIND