Quasi-coherent fluctuation measurement with the upgraded microwave imaging reflectometer in KSTAR. (1st October 2018)

• Record Type: Journal Article
• Authors: Lee, W; Leem, J; Lee, D J; Choi, M J; Park, H K; Lee, J A; Yun, G S; Kim, T G; Park, H; Kim, K W
• Other Names: collab.
• Is Part Of: Plasma physics and controlled fusion. Volume 60:Number 11(2018:Nov.)
• Publication Date: 2018-10-01
• Subjects: microwave imaging reflectometer -- multi-frequency probe beam source -- multi-channel detector array -- quasi-coherent mode -- coherence analysis; Plasma (Ionized gases) -- Periodicals; Controlled fusion -- Periodicals; 530.44
• DOI: 10.1088/1361-6587/aae0b5
• Languages: English
• ISSNs: 0741-3335

Abstract

Abstract: The microwave imaging reflectometer (MIR) is the leading diagnostic tool for study of density fluctuations in KSTAR. For last three years since 2014, major components such as the multi-frequency probe beam source, multi-channel detector array, signal processing electronic system, data acquisition system, and optical system have been gradually upgraded. In this paper, the detailed system upgrade with test results in the laboratory and/or plasma is given, and analysis results of a distinctive fluctuation structure referred to as the quasi-coherent mode (QCM) measured by the upgraded MIR system for an L-mode discharge are presented. Cross-coherence analysis with multiple channels shows that the QCM is localized in a core region and appears to be driven by electron temperature gradient for the discharge.