title: Design of a collective scattering system for small scale turbulence study in Korea Superconducting Tokamak Advanced Research.
abstract: The design characteristics of a multi-channel collective (or coherent) scattering system for small scale turbulence study in Korea Superconducting Tokamak Advanced Research (KSTAR), which is planned to be installed in 2017, are given in this paper. A few critical issues are discussed in depth such as the Faraday and Cotton-Mouton effects on the beam polarization, radial spatial resolution, probe beam frequency, polarization, and power. A proper and feasible optics with the 300 GHz probe beam, which was designed based on these issues, provides a simultaneous measurement of electron density fluctuations at four discrete poloidal wavenumbers up to 24 cm(-1). The upper limit corresponds to the normalized wavenumber kθρe of ∼0.15 in nominal KSTAR plasmas. To detect the scattered beam power and extract phase information, a quadrature detection system consisting of four-channel antenna/detector array and electronics will be employed.
authors.affiliation: Ulsan National Institute of Science and Technology, Ulsan 44919, South Korea.
authors.forename: W
authors.initials: W
authors.lastname: Lee
authors.affiliation: Ulsan National Institute of Science and Technology, Ulsan 44919, South Korea.
authors.forename: H K
authors.initials: HK
authors.lastname: Park
authors.affiliation: Ulsan National Institute of Science and Technology, Ulsan 44919, South Korea.
authors.forename: D J
authors.initials: DJ
authors.lastname: Lee
authors.affiliation: National Fusion Research Institute, Daejeon 34133, South Korea.
authors.forename: Y U
authors.initials: YU
authors.lastname: Nam
authors.affiliation: Pohang University of Science and Technology, Pohang, Gyeongbuk 37673, South Korea.
authors.forename: J
authors.initials: J
authors.lastname: Leem
authors.affiliation: Kyunpook National University, Daegu 41566, South Korea.
authors.forename: T K
authors.initials: TK
authors.lastname: Kim