Search engine for discovering works of Art, research articles, and books related to Art and Culture
Javascript must be enabled to continue!
Non-Maxwellianity of ion velocity distributions in the Earth's magnetosheath
View through CrossRef
Collisions are nearly negligible in many space and astrophysical plasmas, allowing charged-particle velocity distribution functions (VDFs) to depart from local thermodynamic equilibrium (LTE). How collisionless plasmas relax these non-LTE distributions and convert turbulent energy into particle heating remains an open question. We investigate deviations from LTE in ion velocity distribution functions (iVDFs) within collisionless plasma turbulence using high-resolution measurements from the Magnetospheric Multiscale (MMS) mission. We find that the iVDFs' non-bi-Maxwellian features are widespread and can be significant. Their complexity increases with ion plasma beta and turbulence intensity, with pronounced high-order non-LTE features emerging during intervals of large-amplitude magnetic field fluctuations. In addition, we show that turbulence-induced magnetic curvature plays a significant role in ion scattering and contributes to the isotropization of the iVDF. These results highlight the complex interaction between turbulence and the velocity distribution of charged particles, providing new insight into the kinetic processes responsible for energy conversion in collisionless plasmas.
Title: Non-Maxwellianity of ion velocity distributions in the Earth's magnetosheath
Description:
Collisions are nearly negligible in many space and astrophysical plasmas, allowing charged-particle velocity distribution functions (VDFs) to depart from local thermodynamic equilibrium (LTE).
How collisionless plasmas relax these non-LTE distributions and convert turbulent energy into particle heating remains an open question.
We investigate deviations from LTE in ion velocity distribution functions (iVDFs) within collisionless plasma turbulence using high-resolution measurements from the Magnetospheric Multiscale (MMS) mission.
We find that the iVDFs' non-bi-Maxwellian features are widespread and can be significant.
Their complexity increases with ion plasma beta and turbulence intensity, with pronounced high-order non-LTE features emerging during intervals of large-amplitude magnetic field fluctuations.
In addition, we show that turbulence-induced magnetic curvature plays a significant role in ion scattering and contributes to the isotropization of the iVDF.
These results highlight the complex interaction between turbulence and the velocity distribution of charged particles, providing new insight into the kinetic processes responsible for energy conversion in collisionless plasmas.
Related Results
Theia can arrive late and be oxidized, but not if it is large compared to proto-Earth
Theia can arrive late and be oxidized, but not if it is large compared to proto-Earth
The Moon-forming impact was the most significant event during the accretion of Earth substantially establishing the physical and chemical states of the Earth-Moon system. In the ca...
Three-dimensional Global Hybrid Simulation of Magnetosheath Jets at Mercury 
Three-dimensional Global Hybrid Simulation of Magnetosheath Jets at Mercury 
Plasma high-speed jets are common in Earth’s magnetosheath, and they significantly perturb the magnetosheath and affect the magnetosphere. The space environment of Mercur...
Modeling Mercury's magnetosheath by the potential-mapping method 
Modeling Mercury's magnetosheath by the potential-mapping method 
Modeling the plasma and magnetic field state in Mercury's magnetosheath is one of the most urgent tasks in Mercury science in view of the upcoming BepiColombo mission. By consideri...
Classifying the magnetosheath using local measurements from MMS
Classifying the magnetosheath using local measurements from MMS
The Earth’s magnetosheath is a dynamic region and its properties strongly depend on the angle between the bow shock normal and the solar wind magnetic field (θbn...
Conformally-mapped planetary magnetosheath model
Conformally-mapped planetary magnetosheath model
A high-precision model of steady-state plasma flow and magnetic field in the planetary magnetosheath region is proposed by introducing the concept of conformal mapping and transfor...
Identification of low‐frequency fluctuations in the terrestrial magnetosheath
Identification of low‐frequency fluctuations in the terrestrial magnetosheath
On the basis of MHD theory we develop a scheme for distinguishing among the four low‐frequency modes which may propagate in a high‐β anisotropic plasma such as the magnetosheath: t...
Measures of correlation length at Earth’s quasi-parallel and quasi-perpendicular bow shock
Measures of correlation length at Earth’s quasi-parallel and quasi-perpendicular bow shock
Turbulent plasmas such as the solar wind and the magnetosheath exhibit an energy cascade which is present across a broad range of scales, from the stirring scale at which energy is...
On the scale sizes of magnetosheath jets
On the scale sizes of magnetosheath jets
<p>The subsolar magnetosheath is oftentimes permeated by jets. These are localized entities of enhanced dynamic pressure with respect to the ambient plasma. Magnetosh...