Measurements of Lower-Hybrid Waves with an Interferometer on the TST-2 Spherical Tokamak

POSTER

Abstract

Development of non-inductive startup scenarios is a critical issue for spherical tokamaks due to limited space at the center of the machine. Among the various methods, the TST-2 group has been focused on startups using rf waves. Recently, an electrostatically coupled combline antenna that launches lower-hybrid waves was installed for the starup experiments. Direct measurements of waves provide valuable information about wave propagation and damping. Interferometer signals are simply the line-integrated electron density, and suited for accurate quantitative studies. Design of a new interferometer to measure small scale fluctuations and a full-wave analysis of lower-hybrid waves for the relevant discharges will be presented. Comparison with the actual measurements will also be shown if available.

Authors

  • N. Tsujii

    • The University of Tokyo

  • A. Ejiri

    • The University of Tokyo

  • K. Ikeuchi

    • The University of Tokyo

  • T. Shinya

    • The University of Tokyo

  • Y. Takase

    • The University of Tokyo

  • T. Wakatsuki

    • The University of Tokyo

  • S. Yajima

    • The University of Tokyo

  • H. Furui

    • The University of Tokyo

  • J. Hiratsuka

    • The University of Tokyo

  • K. Imamura

    • The University of Tokyo

  • T. Inada

    • The University of Tokyo

  • H. Kakuda

    • The University of Tokyo

  • K. Nakamura

    • The University of Tokyo

  • A. Nakanishi

    • The University of Tokyo

  • T. Oosako

    • The University of Tokyo

  • M. Sonehara

    • The University of Tokyo

  • H. Togashi

    • The University of Tokyo

  • S. Tsuda

    • The University of Tokyo

  • T. Yamaguchi

    • The University of Tokyo

  • C.P. Moeller

    • General Atomics