抄録
The multi-channel ion Doppler spectroscopic (M-IDS) system using a fast camera as detectors has been newly developed to measure the spatial profiles of impurity spectral line emissions from plasmas. The M-IDS system developed with 8 viewing chords is characterized by the simplest optical systems, a fast sampling frequency, high number of shooting and a low crosstalk of 3.5% on each chord. In order to verify the usefulness and reliability of the M-IDS system, we have applied it for the start-up plasma produced in the Helicity Injected Spherical Torus (HIST) device. Resultantly, we have successfully measured the radial profiles of Doppler ion temperature Ti.D and Doppler ion velocity vi.D of the plasma with a good Gaussian fitting. However, we have found that the sampling frequency is upper limited by 25 kHz because the signal detected with a faster frequency from the CIII impurity line emission is too weak to be analyzed, so that the sensitivity of the total system needs to be improved.
