Plasma stabilization device

Purpose: To prevent plasma current interruption in a tokamak type thermonuclear device effectively even at a high temperature of plasmas without complicating the reactor structures. Constitution: Fluctuating poroidal magnetic fields are detected by an electromagnetic probe disposed at the periphery of plasmas in a tokamak type thermonuclear device, to estimate the width of magnetic islands generated in the plasmas based on the result of the detection. High frequency waves in a frequency region corresponding to the hybrid waves at a low frequency region of plasmas are generated from an oscillation tube. A phase shifter shifts the phase of the oscillated high frequency waves depending on the estimated magnetic island width. Then, a grill type antenna radiates the phase-shifted high frequency waves as the travelling waves in the torus direction into the plasmas. In this way, by forcively driving the plasma currents with high frequency waves, the forebonding phenomenon can be suppressed to prevent the plasma current interruption. (Horiuchi, T.)