中国物理B ›› 2008, Vol. 17 ›› Issue (8): 2994-3002.doi: 10.1088/1674-1056/17/8/039

• PHYSICS OF GASES, PLASMAS, AND ELECTRIC DISCHARGES • 上一篇    下一篇

Stability analysis of viscous Z-pinch plasma with a sheared axial flow

张 扬, 丁 宁   

  1. Institute of Applied Physics and Computational Mathematics, PO Box 8009, Beijing 100088, China
  • 收稿日期:2007-09-04 修回日期:2008-03-17 出版日期:2008-08-20 发布日期:2008-08-20
  • 基金资助:
    Project supported by the National Science Foundation of China (Grant Nos 10575014 and 10635050).

Stability analysis of viscous Z-pinch plasma with a sheared axial flow

Zhang Yang(张扬) and Ding Ning(丁宁)   

  1. Institute of Applied Physics and Computational Mathematics, PO Box 8009, Beijing 100088, China
  • Received:2007-09-04 Revised:2008-03-17 Online:2008-08-20 Published:2008-08-20
  • Supported by:
    Project supported by the National Science Foundation of China (Grant Nos 10575014 and 10635050).

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摘要： Within the magnetohydrodynamics (MHD) frame, we analyse the effect of viscosity on magneto-Rayleigh--Taylor (MRT) instability in a Z-pinch configuration by using an exact method and an approximate method separately. It is demonstrated that the plasma viscosity indeed has a stabilization effect on the MRT mode in the whole wavenumber region, and its influence increases with the perturbation wavenumber increasing. After the characteristics and feasibility of the approximate method have been investigated, we apply it to the stability analysis of viscous plasma where a sheared axial flow (SAF) is involved, and we attain an analytical dispersion relation. It is suggested that the viscosity and the SAF are complemental with each other, and a wide wavenumber range of perturbation is possible to be restrained if the SAF and the viscosity are large enough. Finally, we calculate the possible value of viscosity parameter according to the current experimental conditions, and the results show that since the value of viscosity is much less than the threshold value, its mitigation effect is small enough to be neglected. The role of the viscosity in the stabilization becomes considerable only if special techniques are so developed that the Z-pinch plasma viscosity can be increased greatly.

Abstract: Within the magnetohydrodynamics (MHD) frame, we analyse the effect of viscosity on magneto-Rayleigh--Taylor (MRT) instability in a Z-pinch configuration by using an exact method and an approximate method separately. It is demonstrated that the plasma viscosity indeed has a stabilization effect on the MRT mode in the whole wavenumber region, and its influence increases with the perturbation wavenumber increasing. After the characteristics and feasibility of the approximate method have been investigated, we apply it to the stability analysis of viscous plasma where a sheared axial flow (SAF) is involved, and we attain an analytical dispersion relation. It is suggested that the viscosity and the SAF are complemental with each other, and a wide wavenumber range of perturbation is possible to be restrained if the SAF and the viscosity are large enough. Finally, we calculate the possible value of viscosity parameter according to the current experimental conditions, and the results show that since the value of viscosity is much less than the threshold value, its mitigation effect is small enough to be neglected. The role of the viscosity in the stabilization becomes considerable only if special techniques are so developed that the Z-pinch plasma viscosity can be increased greatly.

Key words: Z-pinch, magneto-Rayleigh-Taylor (MRT) instability, viscosity, sheared axial flow

中图分类号:  (Z-pinches, plasma focus, and other pinch devices)

  • 52.58.Lq
52.25.Fi (Transport properties) 52.30.Cv (Magnetohydrodynamics (including electron magnetohydrodynamics)) 52.35.Py (Macroinstabilities (hydromagnetic, e.g., kink, fire-hose, mirror, ballooning, tearing, trapped-particle, flute, Rayleigh-Taylor, etc.)) 52.65.Kj (Magnetohydrodynamic and fluid equation)