实验先进超导托卡马克装置中的八通道多普勒背散射系统。

An eight-channel Doppler backscattering system in the experimental advanced superconducting tokamak.

作者信息

Hu J Q, Zhou C, Liu A D, Wang M Y, Doyle E J, Peebles W A, Wang G, Zhang X H, Zhang J, Feng X, Ji J X, Li H, Lan T, Xie J L, Ding W X, Liu W D, Yu C X

机构信息

KTX Laboratory and Department of Modern Physics, University of Science and Technology of China, Anhui Hefei 230026, China.

Physics and Astronomy Department and PSTI, University of California, Los Angeles, California 90095, USA.

出版信息

Rev Sci Instrum. 2017 Jul;88(7):073504. doi: 10.1063/1.4991855.

DOI:10.1063/1.4991855

PMID:28764527

Abstract

Doppler backscattering system can measure the perpendicular velocity and fluctuation amplitude of the density turbulence with intermediate wavenumber. An eight-channel Doppler backscattering system has been installed in the Experimental Advanced Superconducting Tokamak (EAST), which can probe eight different radial locations simultaneously by launching eight fixed frequencies (55, 57.5, 60, 62.5, 67.5, 70, 72.5, 75 GHz) into plasma. The quasi-optical system consists of circular corrugated waveguide transmission, a fixed parabolic mirror, and a rotatable parabolic mirror which are integrated with quasi-optics front-end of the profile reflectometer inside the vacuum vessel. The incidence angle can be chosen from 5° to 12°, and the wavenumber range is 2-15/cm with the wavenumber resolution Δk/k≤0.21. Ray tracing simulations are used to calculate the scattering locations and the perpendicular wavenumber. The dynamic range of this new eight-channel Doppler backscattering system can be as large as 40 dB in the EAST. In this article, the hardware design, the ray tracing, and the preliminary experimental results in the EAST will be presented.

摘要

多普勒背散射系统能够测量具有中间波数的密度湍流的垂直速度和涨落幅度。一个八通道多普勒背散射系统已安装在超导托卡马克实验装置（EAST）中，它可以通过向等离子体发射八个固定频率（55、57.5、60、62.5、67.5、70、72.5、75吉赫兹）同时探测八个不同的径向位置。准光学系统由圆形波纹波导传输、一个固定抛物面镜和一个可旋转抛物面镜组成，它们与真空容器内剖面反射计的准光学前端集成在一起。入射角可在5°至12°之间选择，波数范围为2 - 15/厘米，波数分辨率Δk/k≤0.21。利用光线追迹模拟来计算散射位置和垂直波数。在EAST中，这个新的八通道多普勒背散射系统的动态范围可达40分贝。本文将介绍其硬件设计、光线追迹以及在EAST中的初步实验结果。