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

Title: Fast, purely growing collisionless reconnection as an eigenfunction problem related to but not involving linear whistler waves

Abstract

If either finite electron inertia or finite resistivity is included in 2D magnetic reconnection, the two-fluid equations become a pair of second-order differential equations coupling the out-of-plane magnetic field and vector potential to each other to form a fourth-order system. The coupling at an X-point is such that out-of-plane even-parity electric and odd-parity magnetic fields feed off each other to produce instability if the scale length on which the equilibrium magnetic field changes is less than the ion skin depth. The instability growth rate is given by an eigenvalue of the fourth-order system determined by boundary and symmetry conditions. The instability is a purely growing mode, not a wave, and has growth rate of the order of the whistler frequency. The spatial profile of both the out-of-plane electric and magnetic eigenfunctions consists of an inner concave region having extent of the order of the electron skin depth, an intermediate convex region having extent of the order of the equilibrium magnetic field scale length, and a concave outer exponentially decaying region. If finite electron inertia and resistivity are not included, the inner concave region does not exist and the coupled pair of equations reduces to a second-order differential equation having non-physicalmore » solutions at an X-point.« less

Authors:
 [1]
  1. Applied Physics and Materials Science, Caltech, Pasadena, California 91125 (United States)
Publication Date:
OSTI Identifier:
22299651
Resource Type:
Journal Article
Journal Name:
Physics of Plasmas
Additional Journal Information:
Journal Volume: 21; Journal Issue: 10; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 1070-664X
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; DIFFERENTIAL EQUATIONS; EIGENFUNCTIONS; EIGENVALUES; ELECTRONS; EQUILIBRIUM; INSTABILITY GROWTH RATES; MAGNETIC FIELDS; MAGNETIC RECONNECTION; MATHEMATICAL SOLUTIONS; MOMENT OF INERTIA; PARITY; WHISTLERS

Citation Formats

Bellan, Paul M. Fast, purely growing collisionless reconnection as an eigenfunction problem related to but not involving linear whistler waves. United States: N. p., 2014. Web. doi:10.1063/1.4897375.
Bellan, Paul M. Fast, purely growing collisionless reconnection as an eigenfunction problem related to but not involving linear whistler waves. United States. https://doi.org/10.1063/1.4897375
Bellan, Paul M. 2014. "Fast, purely growing collisionless reconnection as an eigenfunction problem related to but not involving linear whistler waves". United States. https://doi.org/10.1063/1.4897375.
@article{osti_22299651,
title = {Fast, purely growing collisionless reconnection as an eigenfunction problem related to but not involving linear whistler waves},
author = {Bellan, Paul M.},
abstractNote = {If either finite electron inertia or finite resistivity is included in 2D magnetic reconnection, the two-fluid equations become a pair of second-order differential equations coupling the out-of-plane magnetic field and vector potential to each other to form a fourth-order system. The coupling at an X-point is such that out-of-plane even-parity electric and odd-parity magnetic fields feed off each other to produce instability if the scale length on which the equilibrium magnetic field changes is less than the ion skin depth. The instability growth rate is given by an eigenvalue of the fourth-order system determined by boundary and symmetry conditions. The instability is a purely growing mode, not a wave, and has growth rate of the order of the whistler frequency. The spatial profile of both the out-of-plane electric and magnetic eigenfunctions consists of an inner concave region having extent of the order of the electron skin depth, an intermediate convex region having extent of the order of the equilibrium magnetic field scale length, and a concave outer exponentially decaying region. If finite electron inertia and resistivity are not included, the inner concave region does not exist and the coupled pair of equations reduces to a second-order differential equation having non-physical solutions at an X-point.},
doi = {10.1063/1.4897375},
url = {https://www.osti.gov/biblio/22299651}, journal = {Physics of Plasmas},
issn = {1070-664X},
number = 10,
volume = 21,
place = {United States},
year = {Wed Oct 15 00:00:00 EDT 2014},
month = {Wed Oct 15 00:00:00 EDT 2014}
}