Magnetic fluctuation behaviour of current termination in reversed field pinch

Growth of the magnetic fluctuations due to the m = 1 and m = 2 modes, where m is the poloidal mode number, and succeeding phase-lock of these modes have been found as the precursor phenomena of the rapid destruction of the plasma column (current termination) in reversed field pinch (RFP). By deepening the field reversal at the wall, these precursors disappear, and the plasma current duration becomes much longer. Thus the current termination is closely connected with the growth of MHD instabilities with the m = 1 and m = 2 modes. (author)