摘要
Recently, the L-mode to H-mode (L-H) transition in tokamak plasma confinement was found to be related to the presence of the poloidal flow shear near the plasma edge. An important mechanism is the ion orbit loss caused by interaction with the limiter. A complementary explanation is the generation of poloidal flows by plasma fluctuations via the Reynolds stress and the poloidal spin-up of plasmas from poloidal asymmetryof particle and momentum sources.