OPTIMIZING X-POINT TARGET PLATES

Prior to the 1992 JET experimental campaign new X-point energy dump plates were installed at both top and bottom of the JET vessel. The active areas of the lower plates were covered with beryllium tiles whilst the upper plates were covered with carbon fibre reinforced graphite tiles. This paper describes the design and geometry of the dump plate tile assemblies and how they were modified to optimise the power handling capability of the system and reducing the probability of producing ''hot spots'' leading to carbon or beryllium blooms. The design principles can be generalized to apply to other components such as limiters and divertor target plates. The new JET divertor target plates are described as an example.