Simple Core-SOL-Divertor model and its application to operational space of HT-7U

We develop a simple Core-SOL-Divertor (C-S-D) model to investigate qualitatively the overall features of the operational space for the integrated core and edge plasma. To construct the simple C-S-D model, a simple core plasma model of ITER physics guidelines and a two-point SOL-divertor model are used. The simple C-S-D model is applied to the study of the HT-7U operational space with lower hybrid current drive experiments under various kinds of trade-off for the basic plasma parameters. Effective methods for extending the operation space are also presented. From this study for the HT-7U operation space, it is shown that the C-S-D model is a useful tool to understand qualitatively the overall features of the plasma operation space. (c) 2004 Elsevier B.V. All rights reserved.