Development of a Propagating Millimeter-Wave Beam Position and Profile Monitor in the Oversize Corrugated Waveguide Used in an ECRH System

Abstract

In a high-power electron cyclotron resonance heating (ECRH) system for plasma heating, a long-distance and low-loss transmission system of the millimeter wave is required. A real-time monitor of the millimeter-wave beam position and its intensity profile, which can be used in a high-power, evacuated, and cooled transmission line, is proposed, designed, manufactured, and tested. The beam-position and profile monitor (BPM) consists of a reflector, Peltier-device array, and a heat-sink, which is installed in the reflector-plate of a miterbend. The BPM was tested using both simulated electric heater power and high-power gyrotron output power. The profile obtained from the monitor using the gyrotron output was well agreed with the burn patter on a thermal sensitive paper. Methods of data analysis and mode-content analysis of a propagating millimeter-wave in the corrugated waveguide are proposed.

Analysis Technique of Millimeter-Wave Propagating Modes in an Oversized Corrugated Waveguide Using Developed Beam Profile Monitors

“…Accordingly, the correct coupling of the mmw beam to the corrugated waveguide is required at the waveguide entrance. We have developed a power profile monitor of the mmw beam propagating in the evacuated corrugated waveguide in real-time [1]. The beam profile monitor (BPM) consists of an mmw reflector, a Peltier-device array and a heat-sink.…”