Abstract Charge exchange spectroscopy has been widely used in fusion devices to measure ion temperature, and toroidal and poloidal flow velocities of plasma. For local measurement, especially in the core region of the plasma, the spectrum emitted by the charge exchange reaction between the main plasma ions or impurity ions and the intentionally injected neutral beam should be analyzed so that parameters can be accurately deduced. Since the line-integrated spectrum signal through the line of sight of the diagnostic optics usually contains an unnecessary overlapped spectrum signal, referred to as the background signal, that typically originates from the plasma boundary region, a beam modulation technique is commonly applied to separate the background signal from the measured spectrum. Recently, it has been demonstrated in the KSTAR tokamak that a two-Gaussian fitting (TGF) method can be applied to analyze the spectrum and deduce plasma ion temperature and toroidal rotation velocity profiles of reasonable accuracy without beam modulation. It has been realized that the measurement result by the TGF method can be alternatively used to investigate plasma transport dynamics when beam modulation is prohibited to avoid any possible disturbance inhibiting robust plasma control and stable operation of the neutral beam injection system.

中文翻译：

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用于测量 KSTAR Tokamak 中离子温度和环形等离子体流速的电荷交换光谱的二高斯拟合方法

摘要 电荷交换光谱已广泛应用于聚变装置中以测量离子温度以及等离子体的环形和极向流动速度。对于局部测量，特别是在等离子体的核心区域，应分析主要等离子体离子或杂质离子与有意注入的中性束之间的电荷交换反应所发射的光谱，以便准确推导出参数。由于通过诊断光学器件视线的线积分光谱信号通常包含不必要的重叠光谱信号，称为背景信号，它通常源自等离子体边界区域，因此通常应用光束调制技术来分离来自测量光谱的背景信号。最近，在 KSTAR 托卡马克中已经证明，可以应用二高斯拟合 (TGF) 方法来分析光谱并推导出具有合理精度的等离子体离子温度和环形旋转速度分布，而无需进行光束调制。已经认识到，当禁止束调制时，TGF 方法的测量结果可以替代地用于研究等离子体传输动力学，以避免任何可能的干扰，从而抑制鲁棒的等离子体控制和中性束注入系统的稳定运行。