Quasi-adiabatic dynamics of ions in a bifurcated current sheet

Journal Article · Mon Apr 15 04:00:00 EDT 2013 · Plasma Physics Reports

DOI:https://doi.org/10.1134/S1063780X13040028· OSTI ID:22156263

Kartsev, Yu. I.; Artemyev, A. V.; Zelenyi, L. M. ^[1]

---

1. Russian Academy of Sciences, Space Research Institute (Russian Federation)

The study is devoted to ion dynamics in bifurcated current sheets with a two-peak current-density distribution observed in the Earth's magnetotail and solar wind. The ion motion is described by a Hamiltonian system with two degrees of freedom. The presence of a small parameter {kappa} characterizing the ratio between the amplitudes of the normal and tangential magnetic field components allows one to separate variables into fast and slow ones and introduce the quasi-adiabatic invariant of motion I{sub z}. Conservation of this invariant makes it possible to analytically describe the dynamics of charged particles. Deviations of the particle dynamics from the quasi-adiabatic one, which are caused by the nonconservation of the quasi-adiabatic invariant, are investigated. The jump of the invariant {Delta}I{sub z} is shown to depend on the small parameter according to the power-law {Delta}I{sub z} {approx} {kappa}{sup h}, where the exponent h varies between unity and 3/4, depending on the level of current sheet bifurcation. The obtained dependence of {Delta}I{sub z} on {kappa} coincides with analytic expressions in the limiting cases of nonbifurcated and completely bifurcated current sheets.

• OSTI ID: 22156263
• Journal Information: Plasma Physics Reports, Journal Name: Plasma Physics Reports Journal Issue: 4 Vol. 39; ISSN PPHREM; ISSN 1063-780X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
AMPLITUDES
BIFURCATION
CHARGED PARTICLES
CURRENT DENSITY
DEGREES OF FREEDOM
HAMILTONIANS
MAGNETIC FIELDS
MAGNETOTAIL
SOLAR WIND