Measurement of the 2-dimensional plasma radiation structure during asymmetric radiative collapse by a tangentially viewing infrared imaging video bolometer on LHD

The infrared (IR) imaging video bolometer (IRVB) is a new type of plasma radiation measurement system, which uses an IR camera. For the 4th LHD campaign (2000), the IRVB type has been installed at a tangential port. Very clear helical plasma radiation structures were measured which agreed well with corresponding images of CIII radiation from a CCD camera. A change in the two-dimensional spatial distribution of the radiated power is observed during radiative collapse of the plasma which indicates that the asymmetric radiation is coming from the lower inboard side. (author)