Magnetic Fluctuation Measurement in Sino United Spherical Tokamak Plasma

To investigate the magnetic fluctuations and for further transport study, the poloidal and radial magnetic field t is conducted on the Sino United Spherical Tokamak （SUNIST）. Auto-power spectral density indicares that the magnetic fiuctuation energy mainly concentrates in the frequency region lower than lO kttz. The magnetic field oscillations, which are characterized by harmonic frequencies of 40 kHz, are observed in the scrape- off layer; by contrast, in the plasma core, the magnetic fluctuations are of Gaussian type. The time-frequency profiles show that the poloidal magnetic fluctuations are temporally intermittent. The autocorrelation calculation indicates that the fluctuations in decorrelation time vary between the core and the edge.     

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介绍了在SUNIST装置上进行的ECW辅助欧姆感应电流启动实验。在ECW(2.45GHz/20kW/10ms)和垂直场感应的共同作用下,先驱动起一个较小的等离子体电流(<1kA),再投入欧姆场,可以获得比常规欧姆放电更高的电流爬升速率,提高伏秒数的利用效率。这种启动方式为SUNIST欧姆放电提高了灵活性,可以在不进行硬件改动的前提下增加调节等离子体平衡的余量,拉长放电的持续时间。     

HL-1M装置ECRH系统的研制与实验

在HL-1M装置上研制了一套75GHz、500kW／50ms的大型电子回旋共振加热系统，设计了准光学传输系统和顶部、水平两套天线，对系统进行了调试，获得了最佳的系统参数和运行条件，并开展了各种O模和X模实验。在单管250kW的基波0模的实验中，获得电子温度提高40％，电流位形负剪切分布以及鱼骨模不稳定性研究等重要的物理实验结果。