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

Journal Article · Thu Mar 25 04:00:00 EDT 2010 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.3396299· OSTI ID:21371713

Matteini, Lorenzo ^[1]; Landi, Simone ^[2]; Velli, Marco ^[3]; Hellinger, Petr ^[4]

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1. LESIA, Observatoire de Paris (France)
2. Dipartimento di Astronomia e Scienza dello Spazio, Universita degli Studi di Firenze (Italy)
3. Jet Propulsion Laboratory, Pasadena, California US (United States)
4. Institute of Atmospheric Physics and Astronomical Institute, AS CR, Prague (Czech Republic)

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. The resulting proton distribution functions are reasonable agreement with those observed in situ.

• OSTI ID: 21371713
• Journal Information: AIP Conference Proceedings, Journal Name: AIP Conference Proceedings Journal Issue: 1 Vol. 1216; ISSN APCPCS; ISSN 0094-243X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ANISOTROPY
ASTROPHYSICS
BARYONS
CHARGED PARTICLES
COMPUTERIZED SIMULATION
CYCLOTRON RESONANCE
DISTRIBUTION FUNCTIONS
ELEMENTARY PARTICLES
EXPANSION
FERMIONS
FUNCTIONS
HADRONS
INSTABILITY
IONS
MAGNETIC FIELDS
NONLINEAR PROBLEMS
NUCLEONS
PARAMETRIC INSTABILITIES
PHYSICS
PLASMA EXPANSION
PLASMA INSTABILITY
PLASMA MACROINSTABILITIES
PLASMA SIMULATION
PROTON TEMPERATURE
PROTONS
RADIATIONS
RESONANCE
SIMULATION
SOLAR ACTIVITY
SOLAR PARTICLES
SOLAR PROTONS
SOLAR RADIATION
SOLAR WIND
STELLAR ACTIVITY
STELLAR RADIATION
STELLAR WINDS
TRAPPING