Observation of divertor and core radiation in JT-60U by means of bolometric imaging

An imaging bolometer has been realized for the first time on a tokamak (JT-60U). The imaging bolometer utilizes a 7 cm × 9 cm × 2.5 μm gold foil and an Omega/Micron infrared (IR) camera by Indigo/FLIR (128 × 164 pixels, 70 mK, 30 fps). The imaging bolometer has an array of 12 (toroidal) × 16 (poloidal) (192 in total) channels, a noise equivalent power density of greater than 350 μW/cm2 and a frame rate of 30 fps. The field of view of the imaging bolometer is semi-tangential covering the divertor for more than 100° toroidally in addition to the entire poloidal cross-section. The data clearly shows examples of the radiation changing from strong divertor radiation to core dominated radiation in agreement with the resistive bolometer data.