High efficiency multimegawatt ICH systems

Summary form only given. Modern 100 to 500 kW shortwave broadcast transmitters achieve 70 to 75% `wall socket´ efficiency and high reliability by effectively applying state of the art solid state circuit and power grid tube technology. The authors discuss how this approach may be applied to enhance the performance of future multimegawatt ion cyclotron heating (ICH) systems. It is suggested that the need for improved efficiency and reliability in the ICH systems of future fusion energy research devices can best be met by a system which makes use of recently developed high-power broadcast transmitter power supply/modulator systems in combination with the dissipation and efficiency capabilities of modern high power tubes such as the Varian EIMAC 4CM2500KG. The new power supply/modulator systems economically and efficiently provide the capability to rapidly control the power amplifier´s anode voltage in a few microseconds so that it will be possible to operate the amplifier in a high efficiency mode over a wider range of VSWR (voltage standing wave ratio). Amplifier efficiency increases as high as 20% (to 80%+) may be achieved