Loading and Asymmetry Measurements and Modeling for the National Spherical Torus Experiment Ion Cyclotron Range of Frequencies System
Loading and Asymmetry Measurements and Modeling for the National Spherical Torus Experiment Ion Cyclotron Range of Frequencies System
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DOI：
10.13182/fst03-a297
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发表时间：
2003-06
影响因子：
0.9
通讯作者：
D. Swain;M. Carter;J. Wilson;P. Ryan;J. Wilgen;J. Hosea;A. Rosenberg
中科院分区：
文献类型：
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作者：
D. Swain;M. Carter;J. Wilson;P. Ryan;J. Wilgen;J. Hosea;A. Rosenberg
国家球面环面实验（NSTX）上的离子回旋加热和电流驱动系统在脉冲长度超过100毫秒的情况下，在不同的天线相位下，可靠地提供了超过3兆瓦的功率。建立了包含12个耦合天线和6个射频源的系统电路模型，该模型与真空测量结果吻合良好。当用它来实验确定系统在不同等离子体条件下的s矩阵时，可以看到s矩阵的非对角线值明显不对称。利用RANT3D代码计算了等离子体存在下的s矩阵，并在天线前测量了边缘密度分布；这些与测量结果非常吻合。这种不对称性主要是由天线前磁场的大俯仰角和等离子体边缘的梯度引起的。
The ion cyclotron heating and current drive system on the National Spherical Torus Experiment (NSTX) has delivered over 3 MW reliably for pulse lengths over 100 ms with various phasings of the antennas. A circuit model of the system that includes the 12 coupled antennas and six radio-frequency sources has been developed that gives good agreement with vacuum measurements. When it is used to experimentally determine the S-matrix of the system under different plasma conditions, pronounced asymmetries in the off-diagonal values of the S-matrix are seen. The S-matrix in the presence of plasma has been calculated with the RANT3D code using measured edge density profiles in front of the antenna; these agree remarkably well with the measurements. The asymmetry is caused primarily by the large pitch angle of the magnetic field in front of the antenna, coupled with the gradients in the plasma edge.