Qu Hao, Zhang Tao, Han Xiang, Wen Fei, Zhang Shoubiao, Kong Defeng, Wang Yumin, Gao Yu, Huang Canbin, Cai Jianqing, Gao Xiang
Institute of Plasma Physics, Chinese Academy of Sciences, P.O. Box 1126, Hefei, Anhui 230031, People's Republic of China.
Rev Sci Instrum. 2015 Aug;86(8):083503. doi: 10.1063/1.4927683.
An X-mode polarized V band (50 GHz-75 GHz) radial and poloidal correlation reflectometry is designed and installed on Experimental Advanced Superconducting Tokamak (EAST). Two frequency synthesizers (12 GHz-19 GHz) are used as sources. Signals from the sources are up-converted to V band using active quadruplers and then coupled together for launching through one single pyramidal antenna. Two poloidally separated antennae are installed to receive the reflected waves from plasma. This reflectometry system can be used for radial and poloidal correlation measurement of the electron density fluctuation. In ohmically heated plasma, the radial correlation length is about 1.5 cm measured by the system. The poloidal correlation analysis provides a means to estimate the fluctuation velocity perpendicular to the main magnetic field. In the present paper, the distance between two poloidal probing points is calculated with ray-tracing code and the propagation time is deduced from cross-phase spectrum. Fluctuation velocity perpendicular to the main magnetic field in the core of ohmically heated plasma is about from -1 km/s to -3 km/s.
一种X模式极化的V波段（50吉赫兹 - 75吉赫兹）径向和极向相关反射仪被设计并安装在先进超导托卡马克实验装置（EAST）上。两个频率合成器（12吉赫兹 - 19吉赫兹）用作信号源。来自信号源的信号通过有源四倍频器上变频到V波段，然后耦合在一起通过一个单一的角锥天线发射。安装了两个沿极向分开的天线来接收来自等离子体的反射波。该反射仪系统可用于电子密度涨落的径向和极向相关测量。在欧姆加热等离子体中，通过该系统测量的径向相关长度约为1.5厘米。极向相关分析提供了一种估计垂直于主磁场的涨落速度的方法。在本文中，用射线追踪代码计算了两个极向探测点之间的距离，并从交叉相位谱推导出传播时间。欧姆加热等离子体核心中垂直于主磁场的涨落速度约为 - 1千米/秒至 - 3千米/秒。
