First Wall Inboard Limiter Design Development for the Compact Ignition Tokamak

The purpose of the inboard limiter of the Compact Ignition Tokamak (CIT) is to protect the vacuum vessel from high heat loads during operation. The limiter components must be maintained remotely; therefore, they must be designed to reduce maintenance time as much as possible. This drives the design toward larger tiles to reduce the number of items to be replaced; however, other factors drive the design toward smaller tiles. The thickness of the tiles must also be as small as possible to reduce overall build of the distance from the inner magnet leg to the plasma. This paper presents the factors involved in sizing of the tiles and shows design concepts for several sizes of tiles. It also discusses the material development that has been accomplished to date and the development in work to increase the thermal conductivity and strength of carbon-carbon materials for use as the limiter material.