Fig. 2-18 Concept of ITER

Table 2-2 Major design specifications of ITER (interim design report, December 1995)

Fig. 2-19 Structure of shield blank

Table 2-3

ITER physics R&D issues

(1) confinement and transport (2) energetic particles, heating and current drive (3) disruptions, plasma control and MHD* (4) divertor physics (5) diagnostics (6) confinement modelling and data base (7) divertor modelling and data base

*magneto hydrodynamics

Four years have already passed since the Engineering Design Activities (EDA) of the International Thermonuclear Experimental Reactor (ITER) started under the collaboration of the European Union, Japan, the Russian Federation and the United States of America and the interim design report was completed and submitted to the ITER council. As summarized in Table 2-2, some design modifications were made of the outline design of January 1994 on the basis of the latest outcome of fusion physics research and technology development in the world. Major modifications made are the magnitude of the plasma current and the heating power, the number of the toroidal field coils and the concept of the blanket structure. Figure 2-18 shows the concept of ITER based on the interim design and in Fig. 2-19 the change in the shield blanket structure is schematically illustrated. The point of this modification is to adopt a module structure for the sake of easier remote operation and maintenance. An extensive engineering R&D on a prototypical scale that involves fabrication and test of major components is schematically shown in Fig. 2-18 and a system for remote operation and maintenance of the blanket and the divertor is being performed, shared among the four participants. The physics R&D on the basis of voluntary contributions from the participant's own domestic program is also in progress under the organization of the ITER physics committee. Major subjects of the physics R&D identified are summarized in Table 2-3. Recently a review of urgent physics issues for the physics design of ITER including empirical scaling laws of plasma confinement and the required heating power for obtaining an H mode confinement and some other basic issues was made and the findings are reported in the interim design report. The international design team (Joint Central Team) sited at Naka has about 60 scientists and engineers (as of March 1996) and is in charge of the design of ex-vessel systems e.g. superconducting coils, remote maintenance systems, plasma control system, cryostat and thermal shields, neutral beam heating and current drive system, tritium plant, power supplies, and heat transfer systems. The ITER EDA is scheduled to be completed in July 1998.

Reference ITER Interim Design Report (International Atomic Energy Agency), in "Technical Basis for the ITER Interim Design Report, Cost Review and Safety Analysis" ITER EDA Documentation Series No. 7, IAEA, Vienna 1996.

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