多层电流片中双撕裂模耦合的压强效应

应用边界层理论研究了等离子体压强对多层电流片中m≥2的双撕裂模耦合的线性和非线性发展行为的影响.考虑等离子体的压强效应，在一阶近似下，解析求得了环位形中双撕裂模的外区匹配参数Δ′.结果表明，当等离子体β<<1时，等离子体压强对双撕裂模的两有理面模之间通过撕裂模外区发生耦合作用的线性行为没有定性影响.虽然等离子体压强将影响双撕裂模耦合的非线性行为，但是主要表现在对其单模项的影响，而对由于两有理面模之间的耦合作用产生的耦合项的影响却很小.

PRESSURE INFLUENCES ON THE COUPLING OF DOUBLE TEARING MODE IN A MULTIPLE CURRENT SHEET

A boundary theory is used to study the influence of plasma pressure on the coupling behavior of double resistive tearing mode in a multiple current layer. Simple analytic expresses are obtained for the tearing instability parameter Δ under the first leading order, taking account of the effects of plasma pressure. The results show that the inclusion of the plasma pressure does not change the physical properties of linearly coupled double tearing mode when the plasma β1. The plasma pressure influences qualitatively the nonlinear evolution tendency of the double tearing mode. These effects however, are mainly exhibit on the non-coupling term, namely, on the result obtained for single tearing mode, not on the coupling term caused by the coupling of the two rational surface modes through the outer idea region.