skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Distributions of the ion temperature, ion pressure, and electron density over the current sheet surface

Abstract

The distributions of the ion temperature, ion pressure, and electron density over the width (the major transverse dimension) of the current sheet have been studied for the first time. The current sheets were formed in discharges in argon and helium in 2D and 3D magnetic configurations. It is found that the temperature of argon ions in both 2D and 3D magnetic configurations is almost uniform over the sheet width and that argon ions are accelerated by the Ampère force. In contrast, the distributions of the electron density and the temperature of helium ions are found to be substantially nonuniform. As a result, in the 2D magnetic configuration, the ion pressure gradient across the sheet width makes a significant contribution (comparable with the Ampère force) to the acceleration of helium ions, whereas in the 3D magnetic configuration, the Ampère force is counterbalanced by the pressure gradient.

Authors:
; ; ; ;  [1]
  1. Russian Academy of Sciences, Prokhorov General Physics Institute (Russian Federation)
Publication Date:
OSTI Identifier:
22614120
Resource Type:
Journal Article
Resource Relation:
Journal Name: Plasma Physics Reports; Journal Volume: 42; Journal Issue: 6; Other Information: Copyright (c) 2016 Pleiades Publishing, Ltd.; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; ACCELERATION; ARGON; ARGON IONS; ELECTRON DENSITY; HELIUM; HELIUM IONS; ION TEMPERATURE; MAGNETIC FIELD CONFIGURATIONS; PRESSURE GRADIENTS; SHEETS; SURFACES; THREE-DIMENSIONAL CALCULATIONS; TWO-DIMENSIONAL CALCULATIONS

Citation Formats

Kyrie, N. P., E-mail: kyrie@fpl.gpi.ru, Markov, V. S., E-mail: natalya.kyrie@yandex.ru, Frank, A. G., Vasilkov, D. G., and Voronova, E. V. Distributions of the ion temperature, ion pressure, and electron density over the current sheet surface. United States: N. p., 2016. Web. doi:10.1134/S1063780X16060040.
Kyrie, N. P., E-mail: kyrie@fpl.gpi.ru, Markov, V. S., E-mail: natalya.kyrie@yandex.ru, Frank, A. G., Vasilkov, D. G., & Voronova, E. V. Distributions of the ion temperature, ion pressure, and electron density over the current sheet surface. United States. doi:10.1134/S1063780X16060040.
Kyrie, N. P., E-mail: kyrie@fpl.gpi.ru, Markov, V. S., E-mail: natalya.kyrie@yandex.ru, Frank, A. G., Vasilkov, D. G., and Voronova, E. V. 2016. "Distributions of the ion temperature, ion pressure, and electron density over the current sheet surface". United States. doi:10.1134/S1063780X16060040.
@article{osti_22614120,
title = {Distributions of the ion temperature, ion pressure, and electron density over the current sheet surface},
author = {Kyrie, N. P., E-mail: kyrie@fpl.gpi.ru and Markov, V. S., E-mail: natalya.kyrie@yandex.ru and Frank, A. G. and Vasilkov, D. G. and Voronova, E. V.},
abstractNote = {The distributions of the ion temperature, ion pressure, and electron density over the width (the major transverse dimension) of the current sheet have been studied for the first time. The current sheets were formed in discharges in argon and helium in 2D and 3D magnetic configurations. It is found that the temperature of argon ions in both 2D and 3D magnetic configurations is almost uniform over the sheet width and that argon ions are accelerated by the Ampère force. In contrast, the distributions of the electron density and the temperature of helium ions are found to be substantially nonuniform. As a result, in the 2D magnetic configuration, the ion pressure gradient across the sheet width makes a significant contribution (comparable with the Ampère force) to the acceleration of helium ions, whereas in the 3D magnetic configuration, the Ampère force is counterbalanced by the pressure gradient.},
doi = {10.1134/S1063780X16060040},
journal = {Plasma Physics Reports},
number = 6,
volume = 42,
place = {United States},
year = 2016,
month = 6
}
  • The electrical probe diagnostics are very hard to be applied to atmospheric plasmas due to severe perturbation by the electrical probes. To overcome this, the probe for measuring electron temperature and ion current density is indirectly contacted with an atmospheric jet source. The plasma parameters are obtained by using floating harmonic analysis. The probe is mounted on the quartz tube that surrounds plasma. When a sinusoidal voltage is applied to a probe contacting on a quartz tube, the electrons near the sheath at dielectric tube are collected and the probe current has harmonic components due to probe sheath nonlinearity. Frommore » the relation of the harmonic currents and amplitude of the sheath voltage, the electron temperature near the wall can be obtained with collisional sheath model. The electron temperatures and ion current densities measured at the discharge region are in the ranges of 2.7–3.4 eV and 1.7–5.2 mA/cm{sup 2} at various flow rates and input powers.« less
  • The authors adopt a magnetotail model with stretched field lines where ion motions are generally nonadiabatic and where it is assumed that the pressure anisotropy resides only in the electron pressure tensor. They show that the magnetic field lines with p{sub {perpendicular}}>p{sub {parallel}} are less stretched than the corresponding field lines in the isotropic model. For p{sub {parallel}}> p{sub {perpendicular}}, the magnetic field lines become more and more stretched as the anisotropy approaches the marginal firehose limit, p{sub {parallel}}=p{sub {perpendicular}}+B{sup 2}/{mu}{sub 0}. The authors also show that the tail current density is highly enhanced at the firehose limit, a situationmore » that might be subject to a microscopic instability. However, they emphasize that the enhancement in the current density is notable only near the center of the tail current sheet (z=0). Thus it remains unclear whether any microscopic instability can significantly alter the global magnetic field configuration of the tail. By comparing the radius of the field-line curvature at z=0 with the particle`s gyroradius, the authors suspect that even the conventional adiabatic description of electrons may become questionable very close to the marginal firehose limit. 22 refs., 9 figs.« less