Infrared lmaging Bolometry for Long Pulse Discharges on LHD

This diagnostic, known as the segmented mask infrared imaging bolometer (SIB), uses state-of-theart infrared (IR) imaging technology to measure the temperature rise of each pixel in a two dimensional array mask sandwiching the metal foil. We have designed, constructed, installed and calibrated a version of the SIB for the Large Helical Device (LHD). This diagnostic has a two dimensional view (toroidal and poloidal) of the LHD plasma from an upper port. Through calibration, a representative decay time of r = 0.13 sec., and calibration factor of K = 0.80 deg./mW were obtained. In addition, we calculate the time varying incident radiation power at the foil using both calibration parameters. In the 3'd cycle of experiments on LHD, we measured the plasma radiation and show the capability of this diagnostic as a steady-state measurement system.