Feedback stabilization of nonaxisymmetric resistive wall modes in tokamaks. I. Electromagnetic model
Feedback stabilization of nonaxisymmetric resistive wall modes in tokamaks. I. Electromagnetic model
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DOI：
10.1063/1.1287744
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发表时间：
2000-08
影响因子：
2.2
通讯作者：
Yueqiang Liu;A. Bondeson;C. Fransson;B. Lennartson;C. Breitholtz
中科院分区：
文献类型：
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作者：
Yueqiang Liu;A. Bondeson;C. Fransson;B. Lennartson;C. Breitholtz
在环形几何结构中计算研究了托克马克压力驱动模式的主动反馈稳定性。稳定性问题是制定在开环传递函数的传感器线圈中的磁通量导致在反馈线圈中的电流。传递函数由扩展版的MARS稳定性代码计算[A. Bondeson等人，Phys.Fluids B 4，1889（1992）]，并且可以通过低阶有理函数精确地建模。本文分析了具有理想放大器（电流控制）的系统的稳定性。结果表明，反馈与适度的增益，和一个单一的线圈阵列poloidally，给大量的线圈形状的范围内的稳定。最佳设计使用位于电阻壁内的极向场传感器，与壁外相当宽的反馈线圈相结合。通常，反馈不会强烈地修改等离子体生成的磁场扰动。一个未来的伴侣文件[C. M. Fransson等人，Phys. Plasmas（ac.
Active feedback stabilization of pressure-driven modes in tokamaks is studied computationally in toroidal geometry. The stability problem is formulated in terms of open-loop transfer functions for fluxes in sensor coils resulting from currents in feedback coils. The transfer functions are computed by an extended version of the MARS stability code [A. Bondeson et al., Phys. Fluids B 4, 1889 (1992)] and can be accurately modeled by low order rational functions. In the present paper stability is analyzed for a system with an ideal amplifier (current control). It is shown that feedback with modest gain, and a single coil array poloidally, gives substantial stabilization for a range of coil shapes. Optimum design uses sensors for the poloidal field, located inside the resistive wall, in combination with rather wide feedback coils outside the wall. Typically, the feedback does not strongly modify the plasma-generated magnetic field perturbation. A future companion paper [C. M. Fransson et al., Phys. Plasmas (ac...