轴向剪切流对Z箍缩等离子体瑞利-泰勒不稳定性的抑制

The mitigation effect of sheared axial flow on the Rayleigh-Taylor instability in Z-pinch plasma

利用理想磁流体力学模型对有轴向剪切流的Z箍缩等离子体不稳定性进行了分析。给出了可压缩模型的色散关系,分别对可压缩及不可压缩模型中轴向剪切流对Z箍缩等离子体瑞利 泰勒不稳定性的抑制作用进行了比较,讨论了可压缩性对含有轴向剪切流系统不稳定性的影响。结果表明,可压缩性能够减缓瑞利 泰勒 凯尔文 亥姆霍兹(RT KH)模扰动的增长,因而使得轴向剪切流对系统不稳定性的抑制作用表现得更为突出。计算结果还说明,在RT不稳定性线性增长阶段,等离子体温度较低,使用可压缩模型能够更真实地描述系统的状态。

A magnetohydrodynamic formulation is derived to investigate the mitigation effects of the sheared axial flow on the Rayleigh-Taylor (RT) instability in Z-pinch plasma.The dispersion relation of the compressible model is given.The mitigation effects of sheared axial flow on the Rayleigh-Taylor instability of Z-pinch plasma in the compressible and incompressible models are compared respectively,and the effect of compressible on the instability of system with sheared axial flow is discussed.It is found that ,compressibility effects can stabilize the Rayleigh-Taylor/Kelvin-Helmholtz (RT/KH) instability,and this allows the sheared axial flow mitigate the RT instability far more effectively.We also find that,at the early stage of the implosion,if the temperature of the plasma is not very high,the compressible model is much more suitable to describing the state of system than the incompressible one.