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 profiles, and the transport process is affected in turn by the instabilities. Using a one-dimensional code, we have investigated the inter-relationship between instabilities, transport and plasma profile in a tokamak discharge. The results show that the global energy confinement becomes strongly dependent on the boundary transport condition owing to strong coupling between them, and a higher edge temperature would ensure a higher core temperature and hence greater global energy confinement.