Establishment of Cross-Polarization Scattering Method for Measurement of Internal Magnetic-Field Fluctuations in Plasmas

1)在本研究期间，研制了频率为8~18 GHz的交叉极化散射诊断系统，并将其应用于伽马10串列反射镜的中心腔等离子体中，以测量其内部磁场的起伏。该系统使用双极化喇叭作为发射器和接收器，实现了CPS和反射仪的同时测量，从CPS和反射仪两个方面评估了波的密度和磁起伏。2)将CPS诊断系统和反射仪应用于离子回旋频率范围(ICRF)和低频漂移波模式下的电磁等离子体波测量。i)观测与ICRF波相关的波动，以研究射频加热功率的波吸收和阿尔芬离子回旋加速器(AIC)不稳定性的激发的物理机制。从端损通量和…两个方面对AIC模引起的涨落输运进行了评估在AIC模式激发过程中电子的温度增加。ii)随着等离子体β和温度各向异性的增加。AIC模式的振幅变大。离散模式出现了。3)将小波变换应用于CPS信号和反射仪信号的分析。小波时频谱和互相关函数使我们可以估计低频波(-3公里/S)在ExB方向的旋转速度，以及AIC模从中心向磁塞的传播速度(-1000公里/S)。iv)从散射波的角分布获得低频波(&lt；40 kHz)的k欧米伽谱。从k-omega谱脊线上首次证实了电磁漂移波的色散关系。4)对磁起伏产生的电磁波的CPS进行了计算研究。结果表明，对于相对较短波长的局域磁涨落，模式转换波谱信号的峰值频率是由入射波、散射波和磁涨落之间的波数的Bragg共振条件决定的。较少

1)During the period of this research project, a cross-polarization scattering diagnostic system with frequency of 8-18 GHz has been fabricated and applied to the central-cell plasma of the GAMMA 10 tandem mirror in order to measure internal magnetic-field fluctuations. The system utilized dual-polarized horns as a transmitter and a receiver that enabled the simultaneous measurement of the CPS and reflectometry, The density and magnetic fluctuations of the waves were evaluated from both the CPS and reflectometry.2)The CPS diagnostic system and reflectometer were applied to the measurement of electromagnetic plasma waves in the ion cyclotron range of frequencies (ICRF) and low-frequency drift-wave mode.i)The fluctuations associated with ICRF waves were observed to investigate the physics of the wave absorption of RF heating power and the excitation of an Alfven ion cyclotron (AIC) instability. The fluctuation-induced transport due to the AIC mode was evaluated from the end-loss flux and … More temperature of electrons during the excitation of the AIC mode.ii)As the plasma beta and temperature anisotropy increased. the amplitude of the AIC mode became large . and the discrete modes appeared. The adjacent MG modes coupled to excite another low-frequency wave that caused the saturation of the plasma beta.iii)The wavelet transform was applied to the analyses of the CPS and reflectometry signals. The wavelet time-frequency spectrum and cross-correlation function allowed us to estimate the rotation speed of the low-frequency waves (-3 km./s) in the ExB direction, and the propagation speed (-1000 km/s) of the AIC modes from the center towards the magnetic plugs.iv)The k -omega) spectra of the low-frequency wave (< 40 kHz) were obtained from the angular distribution of the scattered waves. From the ridge of the k -omega spectra the.dispersion relation of the electromagnetic drift wave was confirmed for the first time.4)Computational study on the CPS of electromagnetic waves produced by magnetic fluctuations was performed. It was shown that the peak frequencies in the spectral signals of the mode-converted waves were determined from the Bragg resonance condition in the wave number between the incident wave, scattered wave, and magnetic fluctuations for relatively short-wavelength localized magnetic fluctuations. Less