Speaker
Description
The accurate characteristic analysis of corrugated waveguide transmission line (TL) for electron cyclotron resonance heating system is very important for future application in fusion plasma research, including the alignment, mode purity, transmission efficiency and power transmission capability. A test scheme for these purposes has been developed based on 105GHz/1MW/3s gyrotron for 40 meters TL which was designed for HL-3 tokamak. There are 6 miter bends, 1 directional coupler, 1 bellow, 2 pumping tees, 1 DC break, 1 switch and a series of straight waveguides with different lengths. The alignment of the TL is guaranteed according to visualize orthometric lasers in a target integrated in waveguide aperture. The mode contents of the TL are analyzed using phase retrieval method through measuring the wave intensity distribution by IR camera, and the percentage of LP01 mode is up to 94%. The preliminary results also show that the un-evacuated TL can achieve the level of 600-kW power and 500-ms pulse width. All of the experimental results indicate that the TL has an excellent performance for high-power millimeter-wave transmission. Future work will be focused on the power loss analysis of key components and transmission efficiency measurement by re-building the testbed in order to get the comprehensive understanding of the TL.
