A study on the non Maxwellian nature of ion velocity distribution functions using Magnetospheric Multiscale (MMS) data - Archive ouverte HAL Accéder directement au contenu
Poster De Conférence Année : 2017

A study on the non Maxwellian nature of ion velocity distribution functions using Magnetospheric Multiscale (MMS) data

F. Valentini
S. Perri
  • Fonction : Auteur
E. Yordanova
  • Fonction : Auteur
W. R. Paterson
  • Fonction : Auteur
D. J. Gershman
  • Fonction : Auteur
B. L. Giles
  • Fonction : Auteur
C. J. Pollock
  • Fonction : Auteur
J. C. Dorelli
  • Fonction : Auteur
L. A. Avanov
  • Fonction : Auteur
Y. Saito
  • Fonction : Auteur
R. Nakamura
D. Fischer
  • Fonction : Auteur
W. Baumjohann
F. Plaschke
Y. Narita
  • Fonction : Auteur
W. Magnes
C. T. Russell
  • Fonction : Auteur
R. J. Strangeway
  • Fonction : Auteur
Olivier Le Contel

Résumé

The interplanetary space is permeated by a plasma where effects of collisions among particles can be considered negligible. In such a weekly collisional medium, in the range of scales where kinetic effects dominate the plasma dynamics, the particle velocity distribution functions (VDF) are observed to be far from the thermodynamic equilibrium. Moreover, recent numerical self-consistent and nonlinear models of plasma turbulence dynamics have shown the presence of significant non-Maxwellian features in the particle VDFs, caused by kinetic effects, which become dominant in the turbulent cascade at ion scales. In particular, a kinetic hybrid Vlasov-Maxwell (HVM) numerical code, which reproduces the turbulent energy cascade down to ion scales, has highlighted significant departures of the ion VDFs from Maxwellian and a local temperature anisotropy close to current sheets structures generated by the turbulent cascade and close to regions of high ion vorticity.In this work, we make use of the high resolution (150 ms) ion and electron VDFs from Fast Plasma Investigation (FPI) instrument on board MMS and the about 1kHz resolution magnetic field data to investigate the possible presence of non-Maxwellian features in the ion VDFs close to intermittent magnetic structures and regions of high current density and vorticity. The data are relevant to a period where the MMS spacecraft was immersed in the turbulent magnetosheath (see Yordanova et al., 2016). The aim is to compare the analysis made by Valentini et al., 2016 on proton and alpha particles in the HVM simulations with the analysis made on the MMS data, and to deeply characterize the ion dynamics in the near Earth plasma. It is worth mentioning that thanks to its very high resolution plasma data, MMS has given the opportunity to study in details kinetic effects in plasma turbulence, down to electron scales.
Fichier non déposé

Dates et versions

hal-02861283 , version 1 (08-06-2020)

Identifiants

  • HAL Id : hal-02861283 , version 1

Citer

F. Valentini, S. Perri, E. Yordanova, W. R. Paterson, D. J. Gershman, et al.. A study on the non Maxwellian nature of ion velocity distribution functions using Magnetospheric Multiscale (MMS) data. AGU Fall Meeting, Dec 2017, New Orleans, Louisiane, United States. 11, 2017. ⟨hal-02861283⟩
26 Consultations
0 Téléchargements

Partager

Gmail Facebook X LinkedIn More