Peebles W A, Rhodes T L, Hillesheim J C, Zeng L, Wannberg C
University of California, Los Angeles, California 90095, USA.
Rev Sci Instrum. 2010 Oct;81(10):10D902. doi: 10.1063/1.3464266.
Doppler backscattering has emerged in recent years as a powerful diagnostic tool in high temperature fusion plasmas. The technique is sensitive to plasma turbulence flow and has been utilized to determine radial electric field and to study geodesic acoustic modes, zonal flows, and intermediate scale density turbulence. The current manuscript describes a novel technique for creating a stable, multichannel system covering the V-band frequency range (50-75 GHz) which enables simultaneous monitoring of turbulent flows and fluctuation levels at eight distinct spatial locations. The system is based on a high-frequency, low phase noise comb-frequency generator combined with a filter bank and quadrature detection system. The system is now in operation on DIII-D and has allowed monitoring of the flow and turbulence levels across the plasma radius during events such as the L-H transition.
近年来，多普勒背散射已成为高温聚变等离子体中一种强大的诊断工具。该技术对等离子体湍流流动敏感，已被用于确定径向电场，并研究测地声模、带状流和中等尺度密度湍流。本手稿描述了一种用于创建稳定的多通道系统的新技术，该系统覆盖V波段频率范围（50 - 75 GHz），能够同时监测八个不同空间位置的湍流流动和波动水平。该系统基于高频、低相位噪声梳状频率发生器，结合滤波器组和正交检测系统。该系统现已在DIII - D装置上运行，并能够在诸如低杂波电流驱动（L - H）转变等事件期间监测整个等离子体半径范围内的流动和湍流水平。
