Deng Tijian, Lan Tao, Wu Jie, Tan Mingsheng, Xu Hangqi, Zhu Junfeng, Chen Chen, Adil Yolbarsop, Zhang Sen, Wu Jiaren, Zu Yiming, Mao Wenzhe, Li Hong, Xie Jinlin, Liu Ahdi, Liu Zixi, Wu Zhengwei, Wang Hai, Wen Xiaohui, Zhou Haiyang, Wei Zian, Xiao Chijin, Ding Weixing, Zhuang Ge, Liu Wandong
KTX Laboratory and Department of Engineering and Applied Physics, University of Science and Technology of China, Hefei 230026, China.
Rev Sci Instrum. 2019 Dec 1;90(12):123513. doi: 10.1063/1.5121503.
We have developed a parametric method for eliminating the background component of the plasma current, which is measured by a Rogowski coil and polluted by the toroidal magnetic field in the vacuum vessel of the Keda Torus eXperiment (KTX) reversed field pinch (RFP) device. The method considers the toroidal magnetic field windings, the KTX vacuum chamber, and the Rogowski coil as a linear time-invariant system; in this case, a constant frequency response function characterizes the system. Using this response function, the current component caused by pollution from the toroidal magnetic field can be predicted exactly for an arbitrary input current to the toroidal magnetic field windings. Compared with the traditional proportional compensation method, the proposed method has great flexibility and universality and it is potentially applicable to cases in which the toroidal field current signal changes over time with plasma feedback signals. Furthermore, the method can be applied to other similarly affected signals, such as magnetic field signals. As an example, we have corrected the poloidal and toroidal magnetic field signals better to reveal the true physical processes for the RFP state.
我们开发了一种参数化方法，用于消除等离子体电流的背景分量。该电流由罗果夫斯基线圈测量，并受到科达托卡马克实验（KTX）反向场箍缩（RFP）装置真空容器中的环形磁场污染。该方法将环形磁场绕组、KTX真空室和罗果夫斯基线圈视为线性时不变系统；在这种情况下，恒定的频率响应函数表征该系统。利用此响应函数，对于环形磁场绕组的任意输入电流，都可以精确预测由环形磁场污染引起的电流分量。与传统的比例补偿方法相比，该方法具有很大的灵活性和通用性，并且有可能适用于环形场电流信号随等离子体反馈信号随时间变化的情况。此外，该方法可应用于其他受到类似影响的信号，如磁场信号。作为一个例子，我们对极向和环向磁场信号进行了更好的校正，以揭示RFP状态的真实物理过程。
