Full-image operation of fast charge exchange recombination spectroscopy with high-spatial and high-wavelength resolutions in large helical device

Aiming at fully utilizing the spatial resolution of a fast charge exchange recombination spectroscopy (CXS) system, a full-image operation scenario is newly developed. A data analysis procedure is presented. Calibration using a white light source and a neon-enclosed hollow cathode lamp is performed, which provides vertical-stripe separation, horizontal-pixel vs wavelength conversion, and stripe sensitivity. Data from fast and slow CXS systems are compared, providing qualitatively equivalent emission spectra in the same time-integration duration. An asymptotically decreasing trend of noise level with respect to the amount of ensemble averaging (time integration) is confirmed for the fast CXS system. Radial profiles of emission intensity, ion temperature, and toroidal velocity obtained from slow and fast CXS systems are compared, and reasonable agreement is found.