作　　者： ; ; ; ; ; ; ; ; ; ; (向皓明）; (耿康宁）; (黄灿斌）;

机构地区： 深圳大学

出　　处： 《深圳大学学报（理工版）》 2016年第6期606-612,共7页

摘　　要： 在先进实验超导托卡马克（experimental advanced superconducting Tokamak,EAST）装置上研制多道极向相关反射仪诊断,使系统可同时测量8（径向）×2（极向）个位置的电子密度涨落.该系统选用8个固定输出频率（12.5、13.5、14.5、15.0、15.5、16.0、17.0和18.0 GHz）的介质振荡器作为信号源,源输出的信号通过4倍频器倍频至V波段,通过多个3 d B定向耦合器耦合成一路,入射波通过一个20 d B定向耦合器分为2路,其中,主路微波通过一个角锥天线入射进入等离子体,副路微波作为参考信号.接收天线阵列由2个极向间隔为6 cm的角锥天线组成.参考信号和反射信号与频率为14.2 GHz的介质振荡器4倍频之后的输出信号进行混频,混频后的中频信号分别通过放大器、带通滤波器组件和同相正交解调器进行解调.通过该诊断系统,初步观察到了由低约束模式向高约束模式转换的现象,且在ELMfree阶段,台基梯度区域,出现了持续时间在毫秒量级、频率在40~50 k Hz的相干模. The diagnosis of multi-channel poloidal correlation reflectometry has been designed on experimental advanced superconducting Tokamak（ EAST）. The setup enables the measurement of electron density fluctuations at8（ radial） × 2（ poloidal） spatial points simultaneously. Eight dielectric resonator oscillators（ DRO） with frequencies of 12. 5,13. 5,14. 5,15. 0,15. 5,16. 0,17. 0,and 18. 0 GHz are used as sources. Signals from the sources are up-converted to V band using active quadrupler and then coupled together with 3 d B coupler. The output waves are launched by one single antenna after passing through a 20 d B directional coupler which can provide the reference signal. Two poloidally separated antennae with the distance of 6 cm are installed to receive the reflected waves from plasma. The reference and reflected signals are down-converted by mixing with a quadrupled signal from a phaselocked source with frequency of 14. 2 GHz and the resulted intermediate fcequencies passed through an amplifier,filter bank and are detected by in-phase / quadrature（ I / Q） demodulators. The system is used to measure the density fluctuation of plasma. The transitions from the lower confinement modes to high confinement modes are observed.The coherent modes with duration times about few milliseconds and the frequency among 40—50 k Hz at the position of pedestal gradient in the ELM-free phase are also obtained.

关 键 词： 等离子体物理 先进实验超导托卡马克装置 相关反射仪 密度涨落 高约束模式 台基湍流 相干模

领　　域： [理学] [理学]