On the compressibility effect in test particle acceleration by magnetohydrodynamic turbulence

The effect of compressibility in a charged particle energization by magnetohydrodynamic (MHD) fields is studied in the context of test particle simulations. This problem is relevant to the solar wind and the solar corona due to the compressible nature of the flow in those astrophysical scenarios. We...

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Autores principales: González, C.A., Dmitruk, P., Mininni, P.D., Matthaeus, W.H.
Formato: JOUR
Materias:
Acceleration
Charged particles
Compressibility
Electric fields
Electromagnetic fields
Electrons
Incompressible flow
Kinetic theory
Magnetic fields
Turbulence
Compressibility effects
Electron acceleration
Electron pressures
Guide magnetic field
Magnetohydrodynamic turbulence
Numerical experiments
Particle dynamics
Proton acceleration
Magnetohydrodynamics
Acceso en línea:http://hdl.handle.net/20.500.12110/paper_1070664X_v23_n8_p_Gonzalez
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Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires
id todo:paper_1070664X_v23_n8_p_Gonzalez
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spelling todo:paper_1070664X_v23_n8_p_Gonzalez2023-10-03T16:02:35Z On the compressibility effect in test particle acceleration by magnetohydrodynamic turbulence González, C.A. Dmitruk, P. Mininni, P.D. Matthaeus, W.H. Acceleration Charged particles Compressibility Electric fields Electromagnetic fields Electrons Incompressible flow Kinetic theory Magnetic fields Turbulence Compressibility effects Electron acceleration Electron pressures Guide magnetic field Magnetohydrodynamic turbulence Numerical experiments Particle dynamics Proton acceleration Magnetohydrodynamics The effect of compressibility in a charged particle energization by magnetohydrodynamic (MHD) fields is studied in the context of test particle simulations. This problem is relevant to the solar wind and the solar corona due to the compressible nature of the flow in those astrophysical scenarios. We consider turbulent electromagnetic fields obtained from direct numerical simulations of the MHD equations with a strong background magnetic field. In order to explore the flow compressibility effect over the particle dynamics, we performed different numerical experiments: an incompressible case and two weak compressible cases with Mach number M = 0.1 and M = 0.25. We analyze the behavior of protons and electrons in those turbulent fields, which are well known to form aligned current sheets in the direction of the guide magnetic field. What we call protons and electrons are test particles with scales comparable to (for protons) and much smaller than (for electrons) the dissipative scale of MHD turbulence, maintaining the correct mass ratio m e / m i. For these test particles, we show that compressibility enhances the efficiency of proton acceleration, and that the energization is caused by perpendicular electric fields generated between currents sheets. On the other hand, electrons remain magnetized and display an almost adiabatic motion, with no effect of compressibility observed. Another set of numerical experiments takes into account two fluid modifications, namely, electric field due to Hall effect and electron pressure gradient. We show that the electron pressure has an important contribution to electron acceleration allowing highly parallel energization. In contrast, no significant effect of these additional terms is observed for the protons. © 2016 Author(s). Fil:Dmitruk, P. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Mininni, P.D. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_1070664X_v23_n8_p_Gonzalez
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic Acceleration
Charged particles
Compressibility
Electric fields
Electromagnetic fields
Electrons
Incompressible flow
Kinetic theory
Magnetic fields
Turbulence
Compressibility effects
Electron acceleration
Electron pressures
Guide magnetic field
Magnetohydrodynamic turbulence
Numerical experiments
Particle dynamics
Proton acceleration
Magnetohydrodynamics
spellingShingle Acceleration
Charged particles
Compressibility
Electric fields
Electromagnetic fields
Electrons
Incompressible flow
Kinetic theory
Magnetic fields
Turbulence
Compressibility effects
Electron acceleration
Electron pressures
Guide magnetic field
Magnetohydrodynamic turbulence
Numerical experiments
Particle dynamics
Proton acceleration
Magnetohydrodynamics
González, C.A.
Dmitruk, P.
Mininni, P.D.
Matthaeus, W.H.
On the compressibility effect in test particle acceleration by magnetohydrodynamic turbulence
topic_facet Acceleration
Charged particles
Compressibility
Electric fields
Electromagnetic fields
Electrons
Incompressible flow
Kinetic theory
Magnetic fields
Turbulence
Compressibility effects
Electron acceleration
Electron pressures
Guide magnetic field
Magnetohydrodynamic turbulence
Numerical experiments
Particle dynamics
Proton acceleration
Magnetohydrodynamics
description The effect of compressibility in a charged particle energization by magnetohydrodynamic (MHD) fields is studied in the context of test particle simulations. This problem is relevant to the solar wind and the solar corona due to the compressible nature of the flow in those astrophysical scenarios. We consider turbulent electromagnetic fields obtained from direct numerical simulations of the MHD equations with a strong background magnetic field. In order to explore the flow compressibility effect over the particle dynamics, we performed different numerical experiments: an incompressible case and two weak compressible cases with Mach number M = 0.1 and M = 0.25. We analyze the behavior of protons and electrons in those turbulent fields, which are well known to form aligned current sheets in the direction of the guide magnetic field. What we call protons and electrons are test particles with scales comparable to (for protons) and much smaller than (for electrons) the dissipative scale of MHD turbulence, maintaining the correct mass ratio m e / m i. For these test particles, we show that compressibility enhances the efficiency of proton acceleration, and that the energization is caused by perpendicular electric fields generated between currents sheets. On the other hand, electrons remain magnetized and display an almost adiabatic motion, with no effect of compressibility observed. Another set of numerical experiments takes into account two fluid modifications, namely, electric field due to Hall effect and electron pressure gradient. We show that the electron pressure has an important contribution to electron acceleration allowing highly parallel energization. In contrast, no significant effect of these additional terms is observed for the protons. © 2016 Author(s).
format JOUR
author González, C.A.
Dmitruk, P.
Mininni, P.D.
Matthaeus, W.H.
author_facet González, C.A.
Dmitruk, P.
Mininni, P.D.
Matthaeus, W.H.
author_sort González, C.A.
title On the compressibility effect in test particle acceleration by magnetohydrodynamic turbulence
title_short On the compressibility effect in test particle acceleration by magnetohydrodynamic turbulence
title_full On the compressibility effect in test particle acceleration by magnetohydrodynamic turbulence
title_fullStr On the compressibility effect in test particle acceleration by magnetohydrodynamic turbulence
title_full_unstemmed On the compressibility effect in test particle acceleration by magnetohydrodynamic turbulence
title_sort on the compressibility effect in test particle acceleration by magnetohydrodynamic turbulence
url http://hdl.handle.net/20.500.12110/paper_1070664X_v23_n8_p_Gonzalez
work_keys_str_mv AT gonzalezca onthecompressibilityeffectintestparticleaccelerationbymagnetohydrodynamicturbulence
AT dmitrukp onthecompressibilityeffectintestparticleaccelerationbymagnetohydrodynamicturbulence
AT mininnipd onthecompressibilityeffectintestparticleaccelerationbymagnetohydrodynamicturbulence
AT matthaeuswh onthecompressibilityeffectintestparticleaccelerationbymagnetohydrodynamicturbulence
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