Confinement bifurcation by magnetic compression on TUMAN-3

INTRODUCTION Experiments on magnetic compression on different tokamaks have shown superadiabatic increases in the plasma parameters On TUMAN-3 the both enhancement and degradation of the confinement were observed in the minor radius magnetic compression experiments In this paper the results of the new study of the L-H transition triggered by magnetic compression are presented. The feature of the recent experiments was small compression ratio what allowed reducing power input P ∂B/∂t during compression phase. The mechanism of the radial electric field E r origin during magnetic compression is proposed to account for the L-H transition