The collisionless coalescence instability with two-species and in-plane-current effects

Journal Article · Sat Jul 01 04:00:00 EDT 1995 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.871230· OSTI ID:165327

Pritchett, P L ^[1]

---

1. Department of Physics and Institute of Geophysics and Planetary Physics, University of California, Los Angeles, California 90095-1547 (United States)

The investigation by means of particle simulations of the process whereby magnetic island structures tend to merge into larger units is extended to include the effects of electron dynamics and the in-plane components of the currents. With the ions marginally unmagnetized ({rho}{sub {ital i}}/{lambda}{similar_to}1, where {rho}{sub {ital i}} is the asymptotic ion gyroradius and {lambda} is the current sheet half-thickness), the electrons reduce the linear growth rate by some 20%, but they do not alter the basic coalescence physics. During the nonlinear stage of the pairwise merging process, a quadrupole out-of-the-plane magnetic field structure with peak amplitude {similar_to}0.1{ital B}{sub 0} is formed, but this field collapses after the merging is completed. In the parameter regime accessible to the simulations [flux bundle size {ital L}/({ital c}/{omega}{sub {ital pi}}){approx_gt}3 and mass ratio {ital M}{sub {ital i}}/{ital m}{sub {ital e}}{le}36], there is no indication of any significant change in the reconnection rate that could be associated with whistler-mediated reconnection. The sequential merging of 4 islands into one large island leads to the formation of a vacuum X point and substantial particle energization. {copyright} {ital 1995} {ital American} {ital Institute} {ital of} {ital Physics}.

• OSTI ID: 165327
• Journal Information: Physics of Plasmas, Journal Name: Physics of Plasmas Journal Issue: 7 Vol. 2; ISSN PHPAEN; ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
COALESCENCE
COLLISIONLESS PLASMA
EARTH MAGNETOSPHERE
INSTABILITY GROWTH RATES
MAGNETIC ISLANDS
MAGNETIC RECONNECTION
MAGNETOHYDRODYNAMICS
PLASMA MACROINSTABILITIES
WHISTLER INSTABILITY