Excitation of kinetic geodesic acoustic modes by drift waves in nonuniform plasmas
Excitation of kinetic geodesic acoustic modes by drift waves in nonuniform plasmas
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非均匀等离子体中漂移波激发动力测地声模式
DOI：
10.1063/1.4863973
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发表时间：
2014-02
影响因子：
2.2
通讯作者：
Zonca F.
中科院分区：
文献类型：
--
作者：
Qiu Z.;Chen L.;Zonca F.
基于非线性陀螺动力学理论，研究了系统非均匀性和动力学弥散性对漂移波湍流自发激发测地声学模的影响。导出了描述DW参量衰减到GAM和DW下边带的耦合非线性方程组，并通过解析和数值求解，研究了系统非均匀性（如非均匀抗磁频率、DW泵浦的有限径向包络和动力学色散）对DW参量衰减过程的影响。结果表明，对于典型的托卡马克参数，当考虑到DW和GAM有限群速度和动力学色散以及有限径向包络时，参数衰减过程是一种对流不稳定性。然而，当考虑抗磁频率的不均匀性时，参数衰减过程在时间上渐进地变成准指数增长的绝对不稳定性。
Effects of system nonuniformities and kinetic dispersiveness on the spontaneous excitation of Geodesic Acoustic Mode (GAM) by Drift Wave (DW) turbulence are investigated based on nonlinear gyrokinetic theory. The coupled nonlinear equations describing parametric decay of DW into GAM and DW lower sideband are derived and then solved both analytically and numerically to investigate the effects on the parametric decay process due to system nonuniformities, such as nonuniform diamagnetic frequency, finite radial envelope of DW pump, and kinetic dispersiveness. It is found that the parametric decay process is a convective instability for typical tokamak parameters when finite group velocities of DW and GAM associated with kinetic dispersiveness and finite radial envelope are taken into account. When, however, nonuniformity of diamagnetic frequency is taken into account, the parametric decay process becomes, time asymptotically, a quasi-exponentially growing absolute instability.
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影响因子：
2.2
作者：
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通讯作者：
Z. Qiu;Liu Chen;F. Zonca
影响因子：
8.6
作者：
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影响因子：
2.9
作者：
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Jun Yu;Jiaqi Dong
影响因子：
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作者：
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通讯作者：
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作者：
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通讯作者：
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