Rhodes T L, Peebles W A, Nguyen X, Hillesheim J C, Schmitz L, White A E, Wang G
Department of Physics and Astronomy, University of California, Los Angeles, California 90098, USA.
Rev Sci Instrum. 2010 Oct;81(10):10D912. doi: 10.1063/1.3475797.
The quasioptical design of a new integrated Doppler backscattering (DBS) and correlation electron cyclotron emission (CECE) system is presented. The design provides for simultaneous measurements of intermediate wavenumber density and long wavelength electron temperature turbulence behavior. The Doppler backscattering technique is sensitive to plasma turbulence flow and has been utilized to determine radial electric field, geodesic acoustic modes, zonal flows, and intermediate scale (k∼1-6 cm(-1)) density turbulence. The correlation ECE system measures a second turbulent field, electron temperature fluctuations, and is sensitive to long poloidal wavelength (k≤1.8 cm(-1)). The integrated system utilizes a newly installed in-vessel focusing mirror that produces a beam waist diameter of 3.5-5 cm in the plasma depending on the frequency. A single antenna (i.e., monostatic operation) is used for both launch and receive. The DBS wavenumber is selected via an adjustable launch angle and variable probing frequency. Due to the unique system design both positive and negative wavenumbers can be obtained, with a range of low to intermediate wavenumbers possible (approximately -3 to 10 cm(-1)). A unique feature of the design is the ability to place the DBS and CECE measurements at the same radial and poloidal locations allowing for cross correlation studies (e.g., measurement of nT cross-phase).
本文介绍了一种新型集成多普勒背散射（DBS）和相关电子回旋辐射（CECE）系统的准光学设计。该设计可同时测量中间波数密度和长波长电子温度湍流行为。多普勒背散射技术对等离子体湍流流动敏感，已被用于确定径向电场、 geodesic 声模、带状流和中间尺度（k∼1-6 cm(-1)）密度湍流。相关电子回旋辐射系统测量第二个湍流场，即电子温度波动，并且对长极向波长（k≤1.8 cm(-1)）敏感。该集成系统利用新安装的船内聚焦镜，根据频率在等离子体中产生3.5-5厘米的束腰直径。发射和接收都使用单个天线（即单基地操作）。通过可调发射角和可变探测频率选择DBS波数。由于独特的系统设计，可以获得正波数和负波数，范围从低到中间波数（约-3至10 cm(-1)）。该设计的一个独特特点是能够将DBS和CECE测量置于相同的径向和极向位置，以便进行互相关研究（例如，测量nT交叉相位）。
