Abstract
Recently, it is paid attention to the lower hybrid resonance heating as one of the additional heatings of plasma. In this work we produce and report a control circuit which maximizes the ion temperature. A control circuit is constituted to maximize the ion temperature automatically at frequency near the lower hybrid in ECR plasma. A Faraday cup is used as a sensor of the timperature, and a comparator output of the ion temperature is feedback controlled to the matching variable condenser between the rf power supply and the plasma load.
