Installation of a 154 GHz mega-watt gyrotron and its contribution to the extension of plasma parameter regime in LHD

A new 154GHz/ 1MW gyrotron was developed and installed in the Electron Cyclotron Resonance Heating system of LHD. The maximum output power of 1.16MW/ 1sec was achieved. Total injected power into a plasma reached 4.4MW with the existing three 77GHz gyrotrons' power. The 154GHz gyrotron contributed to extend the plasma parameters to higher temperature and density region.