Resonant acceleration of alpha particles by ion cyclotron waves in the solar wind

Journal Article · Sat Jun 01 00:00:00 EDT 1991 · Journal of Geophysical Research; (United States)

DOI:https://doi.org/10.1029/91JA00613· OSTI ID:5318260

Gomberoff, L; Elgueta, R ^[1]

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1. Univ. of Chile, Santiago (Chile)

Preferential acceleration of alpha particles interacting with left-hand polarized ion cyclotron waves is studied. It is shown that a small positive drift velocity between alpha particles and protons can lead to alpha particle velocities well in excess of the proton bulk velocity. During the acceleration process, which is assumed to take place at heliocentric distances less than 0.3 AU, the alpha particle drift velocity should exceed the proton bulk velocity, and then the gap which exists around the alpha particle gyrofrequency should disappear. It is also shown that for proton thermal anisotropies of the order of those observed in fast solar wind, the waves either grow or are not damped excessively, so that the waves can exist and might thus lead to the observed differential speeds. However, the way in which the alpha particles exceed the proton velocity remains unexplained.

• OSTI ID: 5318260
• Journal Information: Journal of Geophysical Research; (United States), Vol. 96:A6; ISSN 0148-0227
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
SOLAR ALPHA PARTICLES
ACCELERATION
SOLAR WIND
ION WAVES
ANALYTICAL SOLUTION
ANISOTROPY
CYCLOTRON FREQUENCY
DATA
DISPERSION RELATIONS
ION DRIFT
SOLAR PROTONS
ALPHA PARTICLES
BARYONS
CHARGED PARTICLES
ELEMENTARY PARTICLES
FERMIONS
HADRONS
INFORMATION
NUCLEONS
PLASMA WAVES
PROTONS
RADIATIONS
SOLAR ACTIVITY
SOLAR PARTICLES
SOLAR RADIATION
STELLAR RADIATION
640104* - Astrophysics & Cosmology- Solar Phenomena