Antenna for unidirectional propagation of fast Alfveacute;n waves in a tokamak

摘要

A slow wave antenna has been designed to propagate Alfveacute;n waves unidirectionally in the Texas Tech Tokamak. The antenna receives 30hyphen;kW rf pulses at 4ndash;20 MHz, directly from a 50hyphen;OHgr; transmission line, without matching circuitry. Unidirectional Alfveacute;n waves are successfully excited in the tokamak over a wide range of frequencies. Power coupling is approximately 36percnt; with a little higher coupling during excitation of a pronounced toroidal eigenmode.