title: Quasi-optical design for systems to diagnose the electron temperature and density fluctuations on EAST.
abstract: A system to simultaneously diagnose the electron temperature and density fluctuations is proposed for Experimental Advanced Superconducting Tokamak device. This system includes a common quasi-optical antenna, a correlation electron cyclotron emission (CECE) system that is used to measure the electron temperature fluctuations and a Doppler backscattering (DBS) system that is used to measure the electron density fluctuations. The frequency range of the proposed CECE system is 108-120 GHz, and this corresponds to a radial coverage of normalized radius ((R - R0)/a, R0= 1850 mm, a = 450 mm) from 0.2 to 0.67 for the plasma operation with a toroidal magnetic field of 2.26 T. This paper focuses on the design of the quasi-optical antenna and aims at optimizing the poloidal resolution for different frequency bands. An optimum result gives the beam radius for the CECE system of 13-15 mm and this corresponds to a wave number range of kθ< 2.4 cm-1. The beam radius is 20-30 mm for V band (50-75 GHz) and 15-20 mm for W band (75-110 GHz).
authors.affiliation: Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031, China.
authors.forename: Qifo
authors.initials: Q
authors.lastname: Cao
authors.affiliation: Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031, China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031, China.
authors.forename: Hailin
authors.initials: H
authors.lastname: Zhao
authors.affiliation: Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031, China.
authors.forename: Tianfu
authors.initials: T
authors.lastname: Zhou
authors.affiliation: Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031, China.
authors.forename: Ang
authors.initials: A
authors.lastname: Ti
authors.affiliation: Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031, China.
authors.forename: Liqun
authors.initials: L
authors.lastname: Hu