Electron cyclotron emission diagnostics for helical plasma in Large Helical Device

Summary form only given, as follows. In LHD, the electron cyclotron emission (ECE) is transmitted from the antenna to the spectrometer for 80 m with the corrugated waveguide system, and the transmission loss is less than 30%. The ECE spectrum is measured by the fast scanning Michelson interferometer, the heterodyne radiometer and the grating polychromator. In order to reduce noise, the Michelson is calibrated with a hot radiation source, which is calibrated to the liquid nitrogen cooled radiation source. The ECE temperature measurement agrees well with the Thomson scattering measurement in the wide range of the electron density. The radiometer is cross-calibrated to the Michelson.