Development of cold isostatic pressing graphite module for a heat-resistant lower hybrid current drive antenna

Development of a plasma facing module using Cold Isostatic Pressing Graphite (CIPG) was successfully achieved for use in driving a heat-resistant Lower Hybrid Current Drive (LHCD) antenna. A thin stainless film (10 mu m), a molybdenum film (10 mu m), and a copper film (50 mu m) were overlaid on the CIPG materials, the CIPG surfaces were successfully coated with the Cu-layer by diffusion bonding method. This module whose length is 206 mm, has four waveguides, and a water cooling channel. High rf-power long pulse operations with water cooling were successfully tested up to 250 kW (125 MW/m(2))/700 s, a stationary temperature and vacuum pressure was performed. But the maximum rf transmission power was limited to 47 MW/m(2) for a plasma facing module using Carbon Fiber Composite (CFC) due to poor Cu-plating, a power density large by more than a factor 2.5 was achieved with the CIPG module. The rf power density which meets the requirement of the rf electric field of 5 kV/cm for a design of the LHCD antenna in International Thermonuclear Experimental Reactor (ITER) was successfully performed. (c) 2005 American Institute of Physics.