THE ITER CHALLENGE

The International Thermonuclear Experimental Reactor (ITER) must provi de an extensive test of concepts and technology required for the desig n and construction of a fusion reactor. This paper examines and offers some solutions to the critical issues related to a reactor, which inc lude: development of a physics understanding of the approach to and co ntrol of ignition; choice of continuous or semi-continuous (long pulse ) operation; development of a fully coherent and robust divertor for p ower exhaust and impurity control; minimisation of the effect of plasm a disruptions; development of advanced materials and components needed for a reactor first wall and blanket, mechanical structure and superc onducting coils; and development of technology for fast and reliable r emote maintenance. The final challenge addressed is the integration of all these different reactor issues into a coherent and cost effective design. Worldwide collaboration, such as the ITER cooperation, is see n as the way to work most efficiently and to achieve effective solutio ns to these scientific and technological challenges.