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Indexed by:期刊论文

Date of Publication:2015-01-01

Journal:PHYSICS OF PLASMAS

Included Journals:SCIE、EI、Scopus

Volume:22

Issue:1

ISSN No.:1070-664X

Abstract:The linear behavior of plasmoid instability in double current sheet configurations, namely, double plasmoid mode (DPM), is analytically and numerically investigated within the framework of a reduced magnetohydrodynamic model. Analytical analysis shows that if the separation of double current sheets is sufficiently small [kappa x(s) << kappa S-2/9(L)1/3], the growth rate of DPMs scales as kappa S-2/3(L)0 in the non-constant-psi regime, where kappa = kL(CS)/2 is the wave vector measured by the half length of the system L-CS/2, 2x(s) is the separation between two resonant surfaces, and S-L = LCSVA/ 2 eta is Lundquist number with V-A and eta being Alfven velocity and resistivity, respectively. If the separation is very large [kappa x(s) >> kappa S-2/9(L)1/3], the growth rate scales as kappa S--2/5(L)2/5 in the constant-psi regime. Furthermore, it is also analytically found that the maximum wave number scales as x(s)(-9/7)S(L)(3/7) at the transition position between these two regimes, and the corresponding maximum growth rate scales as x(s)(-6/7)S(L)(2/7) there. The analytically predicted scalings are verified in some limits through direct numerical calculations. (C) 2015 AIP Publishing LLC.