Different Types of Plasma Turbulence in the Process of Solar Particle Acceleration

Con objeto de reproducir la evolución con energía de los estados de carga observacionales de los iones energéticos solares, hemos desarrollado un modelo en el que los estados de carga se definen en la fuente durante el proceso de aceleración de los iones solares. El intercambio de carga entre iones y la materia local se estudia en base a secciones eficaces de alta energía para pérdida y captura electrónica. El modelo se desarrolla bajo dos enfoques diferentes. Aplicamos el modelo a datos observacionales de estados de carga para la mayor parte los eventos publicados en la literatura. Analizamos y discutimos nuestros resultados e implicaciones dentro del contexto de otros modelos: concluimos que nuestro modelo analítico da mayor información de la física involucrada que las simulaciones numéricas desarrollada por otros autores.

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Plasma turbulence generated during particle acceleration in reconnection current sheets with magnetic islands

10.1002/essoar.10503640.1 ◽

2020 ◽

Author(s):

Qian Xia ◽

Valentina Zharkova

Keyword(s):

Particle Acceleration ◽

Plasma Turbulence ◽

Magnetic Islands ◽

Current Sheets

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A New Field Line Advection Model for Solar Particle Acceleration

The Astrophysical Journal ◽

10.1086/426812 ◽

2004 ◽

Vol 616 (2) ◽

pp. L171-L174 ◽

Cited By ~ 48

Author(s):

I. V. Sokolov ◽

I. I. Roussev ◽

T. I. Gombosi ◽

M. A. Lee ◽

J. Kóta ◽

...

Keyword(s):

Particle Acceleration ◽

Field Line ◽

Solar Particle

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Plasma turbulence generated during particle acceleration in magnetic islands

10.5194/egusphere-egu21-10297 ◽

2021 ◽

Author(s):

Valentina Zharkova ◽

Qian Xia

Keyword(s):

Magnetic Field ◽

Particle Acceleration ◽

Current Sheet ◽

Plasma Turbulence ◽

Lower Hybrid ◽

Diffusion Region ◽

Magnetic Islands ◽

Langmuir Waves ◽

Kink Instability ◽

Hybrid Waves

<div> <div> <div> <p>We investigate plasma turbulence generated during particle acceleration in magnetic islands within 3D Harris-type&#160;reconnecting current sheets (RCSs),using the particle-in-cell approach.&#160;&#160;RCSs with a strong guiding magnetic field &#160;ar shown to lead to&#160;separation of electrons and ions into the opposite sides from the current sheet mid-plane that significantly reduces kink instability along the guiding field direction.&#160;Particles with the same&#160;charge also have asymmetric trajectories forming&#160;two distinct populations of beams: &#8216;transit&#8217; particles, which pass through RCS from&#160;one edge to another, become strongly energised and form nearly unidirectional beams;&#160;and &#8216;bounced&#8217; particles, which are reflected from the diffusion region and move back to&#160;the same side they entered the current sheet, gaining much less energy and forming more&#160;dispersive spatial distributions. Thes&#160;transit and bounced particles form the &#8216;bump-on-tail&#8217; velocity distributions that naturally generate plasma&#160;turbulence. Using the wavelet analysis of electric and magnetic field fluctuations in the&#160;frequency domain, we identified some characteristic waves produced by particle beams.&#160;In particular, we found thre are Langmuir waves near X-nullpoints produced by two electron beam instabilities, while the presence of anisotropic temperature variations inside&#160;magnetic islands lead to whistler waves. The lower-hybrid waves are generated&#160;inside the magnetic islands, owing to the two-stream instabilities of the ions. While the&#160;high-frequency fluctuations, upper hybrid waves, or electron Bernstein waves, pile up near&#160;X-nullpoints.&#160;The results can be beneficial for&#160;understanding in-situ observations with modern space missions of energetic particles in&#160;the heliosphere.</p> </div> </div> </div>

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

10.5194/egusphere-egu21-12010 ◽

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

<p>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&#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].</p>

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