To observe visible spectra with two-dimensional spatial resolution in the divertor region. The spectrometer has 92 view channels (vertically 60 channels, horizontally 32 channels) with a spatial resolution of ~1cm. It covers a spectral range of 350 - 800nm. From the measurement, it is possible to obtain spatial distribution of spectra intensities using a computer tomography technique.
Light collected by lenses is transmitted through optical fivers (~300m) from JT-60U to the spectrometer placed in the diagnostic room. The light is dispersed to the spectrometer with camera lenses to suppress chromatic aberrations and astigmatism, and detected with a back-illuminated CCD camera.
|Viewing chord : 100ch||Focal length : 0.2m (F/2)|
|Grating : 300g/mm||Wavelength band : 450nm|
|Time resolution : 200ms|
|Pixel format : 1340 x 1300 pixels||Size of pixel : 20 x 20 m|
|Imaging area : 26.8 x 26 mm2||Dynamic range : 16bits|
|ADC speed : 1MHz||CCD read noise : 18e- rms|
|Sensitivity : 93% at 550nm|