Effects of cold neutral gases on the high density plasma

Summary form only given, as follows. In order to simulate the radiation cooling effect at tokamak edge plasma, we construct a plasma-material interaction chamber installed various plasma sources such as filament, LaB/sub 6/ (DC), ICP, and helicon plasma, whose diameter is 20cm and length is 150cm. To measure the plasma density, potential, electron and ion temperature variation during the gas injection, a scanning hybrid probe consisting of electric and optical probes is developed. This hybrid probe will be installed at the 'Hanbit' device to monitor the normal mirror plasma and to study the radiation cooling effect during the simulated divertor experiment.