Electromagnetic instabilities driven by unequal proton beams in the solar wind

Journal Article · Tue Jun 01 00:00:00 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), Vol. 81:16
• Country of Publication: United States
• Language: English

Related Subjects

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