Regulation of ion drifts and anisotropies by parametrically unstable finite-amplitude Alfvén-cyclotron waves in the fast solar wind

Journal Article · Mon Mar 10 04:00:00 EDT 2014 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/783/2/139· OSTI ID:22351560

Maneva, Y. G. ^[1]; Araneda, J. A. ^[2]

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1. NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States)
2. Departamento de Física, Universidad de Concepción, 4070386 (Chile)

We study the preferential heating and differential acceleration of minor ions by dissipation of ion-acoustic waves (IAWs) generated by parametric instabilities of a finite-amplitude monochromatic Alfvén-cyclotron pump wave. We consider the associated kinetic effects of Landau damping and nonlinear pitch-angle scattering of protons and α particles in the tenuous plasma of coronal holes and the fast solar wind. Various data collected by Wind spacecraft show signatures for a local transverse heating of the minor ions, presumably by Alfvén-cyclotron wave dissipation, and an unexpected parallel heating by a so far unknown mechanism. Here, we present the results from a set of 1.5 dimensional hybrid simulations in search for a plausible explanation for the observed field-aligned kinetic features in the fast solar wind minor ions. We investigate the origin and regulation of ion relative drifts and temperature anisotropies in low plasma β, fast solar wind conditions. Depending on their initial drifts, both ion species can heat up not only transversely through cyclotron resonance and non-resonant wave-particle interactions, but also strongly in the parallel direction by Landau damping of the daughter IAWs. We discuss the dependence of the relative ion drifts and temperature anisotropies on the plasma β of the individual species and we describe the effect of the pump wave amplitude on the ion heating and acceleration.

• OSTI ID: 22351560
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 2 Vol. 783; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ACCELERATION
ALFVEN WAVES
AMPLITUDES
ANISOTROPY
CYCLOTRON RESONANCE
HEATING
INCLINATION
ION DRIFT
IONS
LANDAU DAMPING
MONOCHROMATIC RADIATION
PARAMETRIC INSTABILITIES
PARTICLE INTERACTIONS
PLASMA
PROTONS
SCATTERING
SIMULATION
SOLAR WIND
SOUND WAVES
TURBULENCE