Radiation losses and global power balance of JT-60 plasmas

Radiation losses and global power balances of the plasmas in the NB heated limiter, outer and lower X-point configurations with TiC coated Molybdenum or graphite first wall have been investigated by bolometric measurements, thermocouples and IRTV camera. Very low radiation losses of the main plasma, 10% of the absorbed power, are realized in NB heated outer X-point discharges with TiC coated molybdenum wall. In the improved divertor confinement (IDC) regime radiation loss from the divertor region increases up to 40% of the absorbed power with the line averaged electron density. That of the main plasma is approximately 20% for any electron density. Intense remote radiative cooling is realized in IDC which reduces the heat load onto divertor plates. (author). 7 refs, 11 figs