High power oscillation experiment of a prototype gyrotron for 300 GHz band collective Thomson scattering diagnostics in LHD

摘要

A high power 300 GHz band pulse gyrotron has been developed for use in the collective Thomson scattering (CTS) diagnostics in Large Helical Device. The design concept for stable and single mode oscillation was experimentally verified with a prototype tube of 295 GHz at the fundamental harmonic. A highest power approaching 250 kW was realized. Based on the results of the prototype tube, design of the next tube is under way for practical use in the CTS experiments.