Wide-spectral-band Spectrometer for Divertor
(Two-dimensional Spatial Measurement)

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.

[Diagnostic method]
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