Effects of the non-uniform initial environment and the guide field on the plasmoid instability

Journal Article · Sat Jun 15 04:00:00 EDT 2013 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.4811144· OSTI ID:22228006

Ni, Lei ^[1]; Lin, Jun ^[1]; Murphy, Nicholas A. ^[2]

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1. Yunnan Astronomical Observatory, Chinese Academy of Sciences, Kunming 650011 (China)
2. Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, Massachusetts 02138 (United States)

Effects of non-uniform initial mass density and temperature on the plasmoid instability are studied via 2.5-dimensional resistive magnetohydrodynamic (MHD) simulations. Our results indicate that the development of the plasmoid instability is apparently prevented when the initial plasma density at the center of the current sheet is higher than that in the upstream region. As a result, the higher the plasma density at the center and the lower the plasma β in the upstream region, the higher the critical Lundquist number needed for triggering secondary instabilities. When β=0.2, the critical Lundquist number is higher than 10{sup 4}. For the same Lundquist number, the magnetic reconnection rate is lower for the lower plasma β case. Oppositely, when the initial mass density is uniform and the Lundquist number is low, the magnetic reconnection rate turns out to be higher for the lower plasma β case. For the high Lundquist number case (>10{sup 4}) with uniform initial mass density, the magnetic reconnection is not affected by the initial plasma β and the temperature distribution. Our results indicate that the guide field has a limited impact on the plasmoid instability in resistive MHD.

• OSTI ID: 22228006
• Journal Information: Physics of Plasmas, Journal Name: Physics of Plasmas Journal Issue: 6 Vol. 20; ISSN PHPAEN; ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
ELECTRIC CURRENTS
ELECTRON TEMPERATURE
ION TEMPERATURE
MAGNETIC RECONNECTION
MAGNETOHYDRODYNAMICS
PLASMA
PLASMA DENSITY
PLASMA INSTABILITY
PLASMA SHEET
PLASMA SIMULATION
PLASMOIDS
TEMPERATURE DISTRIBUTION