On the role of wave-particle interactions in the evolution of solar wind ion distribution functions

0355922 - ÚFA 2011 RIV US eng C - Conference Paper (international conference)
Matteini, L. - Landi, S. - Velli, M. - Hellinger, Petr
On the role of wave-particle interactions in the evolution of solar wind ion distribution functions.
Twelfth International Solar Wind Conference. Proceedings Paper. New York: Melville, 2010 - (Maksimovic, M.; Issautier, K.; Meyer-Vernet, N.; Moncuquet, M.; Pantellini, F.), s. 223-226. AIP Conference Proceedings, 1216. ISBN 978-0-7354-0759-6. ISSN 0094-243X.
[International Solar Wind Conference /12./. Saint-Milo (FR), 21.06.2009-26.06.2009]
Institutional research plan: CEZ:AV0Z30420517
Keywords : Solar Wind * Plasma Simulations * Kinetic Physics * Wave-Particle Interactions
Subject RIV: BL - Plasma and Gas Discharge Physics

We investigate the role of kinetic effects in the solar wind expansion using 1-D numerical hybrid simulations. The analysis of proton distribution functions in the solar wind shows a non-adiabatic evolution and suggests that several kinetic processes are at work during the expansion. From simulation studies wave-particle and wave-wave interactions, as cyclotron heating and non-linear trapping due to parametric instabilities, are found to play an important role on constraining the proton temperature anisotropy and generating secondary velocity beams. We report results from hybrid comoving simulations that self-consistently retain and describe these processes. We find that cyclotron interactions control the evolution of the proton temperature anisotropy with distance providing a perpendicular heating which contrasts the adiabatic cooling caused by the expansion. At the same time ion-acoustic modes driven by parametric effects produce a velocity beam in the proton distribution function.
Permanent Link: http://hdl.handle.net/11104/0194582