SENSITIVITY OF GLOBAL ENERGY CONFINEMENT TO THE BOUNDARY-CONDITION DUE TO COUPLING OF MHD AND TRANSPORT PROCESSES

MHD instabilities are governed by the transport-determined plasma prof iles, and the transport process is affected in turn by the instabiliti es. Using a one-dimensional code, we have investigated the inter-relat ionship between instabilities, transport and plasma profile in a tokam ak discharge. The results show that the global energy confinement beco mes strongly dependent on the boundary transport condition owing to st rong coupling between them, and a higher edge temperature would ensure a higher core temperature and hence greater global energy confinement .