Electron cyclotron wave current startup for ohmic discharges on the CT-6B tokamak

The electron cyclotron wave current startup as a scheme to initiate ohmic d ischarges has been investigated with two circuits of open and shorted prima ry winding of transformer in the CT-6B tokamak, A diode shorted circuit is proposed for connection with ohmic discharges. Two gyrotron systems operate d at different frequencies were used as the wave sources. The experimental results indicate that approximately equivalent transformer flux saving and reduction of starting voltage are achieved in the initial phase of the ohmi c discharges for both circuits. An estimation of plasma resistance for the open circuit shows that no obvious anomalous resistance of the wave started plasma is observed.