TRIAM-1M is a superconducting tokamak, the plasma is maintained by RF (radio frequency) wave completely without ohmic field in the steady-state operation. An active control of plasma current in fully non-inductive lower hybrid current drive (LHCD) plasmas on TRIAM-1M is demonstrated successfully for more than 1 min. A simple model to decide the PID (proportional integral and differential) control parameters based on secondary lower hybrid wave (LHW) is proposed. The PID parameters different from the prediction of the model prevent from maintaining plasma current well.
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