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

2010 ◽  
Author(s):  
Lorenzo Matteini ◽  
Simone Landi ◽  
Marco Velli ◽  
Petr Hellinger ◽  
M. Maksimovic ◽  
...  
Keyword(s):  
Solar Wind ◽  
Distribution Functions ◽  
Particle Interactions ◽  
Ion Distribution ◽  
Wave Particle Interactions

scholarly journals Revisiting the theory of the evolution of pick-up ion distributions: magnetic or adiabatic cooling?

2007 ◽  
Vol 25 (12) ◽  
pp. 2649-2659 ◽  
Author(s):  
H. J. Fahr
Keyword(s):  
Solar Wind ◽  
Particle Interaction ◽  
Distribution Functions ◽  
Particle Interactions ◽  
Ion Distribution ◽  
Ion Distributions ◽  
Magnetic Cooling ◽  
Adiabatic Cooling ◽  
Diffusive Acceleration ◽  
Nonlinear Energy

Abstract. We study the phasespace behaviour of heliospheric pick-up ions after the time of their injection as newly created ions into the solar wind bulk flow from either charge exchange or photoionization of interplanetary neutral atoms. As interaction with the ambient MHD wave fields we allow for rapid pitch angle diffusion, but for the beginning of this paper we shall neglect the effect of quasilinear or nonlinear energy diffusion (Fermi-2 acceleration) induced by counterflowing ambient waves. In the up-to-now literature connected with the convection of pick-up ions by the solar wind only adiabatic cooling of these ions is considered which in the solar wind frame takes care of filling the gap between the injection energy and energies of the thermal bulk of solar wind ions. Here we reinvestigate the basics of the theory behind this assumption of adiabatic pick-up ion reactions and correlated predictions derived from it. We then compare it with the new assumption of a pure magnetic cooling of pick-up ions simply resulting from their being convected in an interplanetary magnetic field which decreases in magnitude with increase of solar distance. We compare the results for pick-up ion distribution functions derived along both ways and can point out essential differences of observational and diagnostic relevance. Furthermore we then include stochastic acceleration processes by wave-particle interactions. As we can show, magnetic cooling in conjunction with diffusive acceleration by wave-particle interaction allows for an unbroken power law with the unique power index γ=−5 beginning from lowest velocities up to highest energy particles of about 100 KeV which just marginally can be in resonance with magnetoacoustic turbulences. Consequences for the resulting pick-up ion pressures are also analysed.

scholarly journals On the coupling between unstable magnetospheric particle populations and resonant high <i>m</i> ULF wave signatures in the ionosphere

2005 ◽  
Vol 23 (2) ◽  
pp. 567-577 ◽  
Author(s):  
L. J. Baddeley ◽  
T. K. Yeoman ◽  
D. M. Wright ◽  
K. J. Trattner ◽  
B. J. Kellet
Keyword(s):  
Wave Energy ◽  
Low Frequency ◽  
Distribution Functions ◽  
Wave Number ◽  
Particle Interactions ◽  
Ion Distribution ◽  
M Wave ◽  
Ulf Wave ◽  
Energy Dissipated ◽  
Giant Pulsations

Abstract. Many theories state that Ultra Low Frequency (ULF) waves with a high azimuthal wave number (m) have their energy source in wave-particle interactions, yet this assumption has been rarely tested numerically and thus many questions still remain as to the waves' exact generation mechanism. For the first time, this paper investigates the cause and effect relationship between the driving magnetospheric particle populations and the ULF wave signatures as observed in the conjugate ionosphere by quantitatively examining the energy exchange that occurs. Firstly, a Monte Carlo method is used to demonstrate statistically that the particle populations observed during conjugate ionospheric high m wave events have more free energy available than populations extracted at random. Secondly, this paper quantifies the energy transferred on a case study basis, for two classes of high m waves, by examining magnetospheric Ion Distribution Functions, (IDFs) and directly comparing these with the calculated wave energy dissipated into the conjugate ionosphere. Estimates of the wave energy at the source and the sink are in excellent agreement, with both being of the order of 1010J for a typical high m wave. Ten times more energy (1011J) is transferred from the magnetospheric particle population and dissipated in the ionosphere when considering a subset of high m waves known as giant pulsations (Pgs). Previous work has demonstrated that 1010J is frequently available from non - Maxwellian IDFs at L=6, whereas 1011J is not. The combination of these studies thus provides an explanation for both the rarity of Pgs and the ubiquity of other high m waves in this region.

Numerical simulation of ion reflection by lunar crustal magnetic fields

2020 ◽  
Author(s):  
Andrey Divin ◽  
Jan Deca ◽  
Charles Lue ◽  
Roman Beliaev
Keyword(s):  
Magnetic Field ◽  
Solar Wind ◽  
Large Scale ◽  
Field Measurements ◽  
Distribution Functions ◽  
Three Dimensions ◽  
Lunar Crust ◽  
Ion Distribution ◽  
Particle In Cell ◽  
Reflection Model

&lt;p&gt;We investigate the dynamics of solar wind - Moon interaction by means of large-scale Particle-in-Cell (PIC) simulations in this study. Implicit moment PIC method and open boundaries are implemented in the code (iPIC3D) allowing to use large-scale domains in three dimensions. Even though the Moon has no global dipolar magnetic field, satellite magnetic field measurements at low-altitude (8-80 km) orbits discovered the presence of patches of intense remanent magnetization of the lunar crust. In order to simulate the scattering effect of the lunar remanent magnetic field we implemented an empirical proton reflection model based on low-attitude survey by the Chandrayaan-1 spacecraft [Lue, 2011]. In this study we focus on the day side effects only and thus do not resolve wake and limb effects. Reflected ions are found to create an energized population of particles in the solar wind and are responsible for sub-ion scale instabilities over the strongest anomalies with non-Maxwellian ion distribution functions.&lt;/p&gt;

scholarly journals Cometary Plasma Waves and Instabilities

1991 ◽  
Vol 116 (2) ◽  
pp. 1171-1210 ◽  
Author(s):  
Bruce T. Tsurutani
Keyword(s):  
Nonlinear Wave ◽  
Nonlinear Waves ◽  
Plasma Waves ◽  
Particle Interactions ◽  
Wave Evolution ◽  
Cometary Plasma ◽  
Plasma Waves And Instabilities ◽  
Wave Particle Interactions

AbstractThis review will discuss various plasma waves and instabilities that have been observed near comets. Comments on nonlinear wave evolution and wave cascading, as well as the role of nonlinear waves in wave-particle interactions, will be made.

Fully kinetic PIC simulations of particle acceleration and non-Maxwellian distribution functions due to current sheets in solar wind turbulence

2021 ◽  
Author(s):  
Patricio A. Munoz ◽  
Jörg Büchner ◽  
Neeraj Jain
Keyword(s):  
Solar Wind ◽  
Particle Acceleration ◽  
Current Sheet ◽  
Plasma Turbulence ◽  
Distribution Functions ◽  
Heat Fluxes ◽  
Magnetic Islands ◽  
Ion Distribution ◽  
Current Sheets ◽  
Particle In Cell

&lt;p&gt;Turbulence is ubiquitous in solar system plasmas like those of the solar wind and Earth's magnetosheath. Current sheets can be formed out of this turbulence, and eventually magnetic reconnection can take place in them, a process that converts magnetic into particle kinetic energy. This interplay between turbulence and current sheet formation has been extensively analyzed with MHD and hybrid-kinetic models. Those models cover all the range between large Alfv&amp;#233;nic scales down to ion-kinetic scales. The consequences of current sheet formation in plasma turbulence that includes electron dynamics has, however, received comparatively less attention. For this sake we carry out 2.5D fully kinetic Particle-in-Cell simulations of kinetic plasma turbulence including both ion and electron spectral ranges. In order to further assess the electron kinetic effects, we also compare our results with hybrid-kinetic simulations including electron inertia in the generalized Ohm's law. We analyze and discuss the electron and ion energization processes in the current sheets and magnetic islands formed in the turbulence. We focus on the electron and ion distribution functions formed in and around those current sheets and their stability properties that are relevant for the micro-instabilities feeding back into the turbulence cascade. We also compare pitch angle distributions and non-Maxwellian features such as heat fluxes with recent in-situ solar wind observations, which demonstrated local particle acceleration processes in reconnecting solar wind current sheets [Khabarova et al., ApJ, 2020].&lt;/p&gt;

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