Design and analysis of a low-edge-temperature divertor for intor

A low edge temperature regime has been proposed for the INTOR divertor in order to minimize erosion on the collector plate. We have examined the design and lifetime issues of a divertor plate operating in such a regime. These issues include the choice of materials, erosion due to sputtering and disruptions, thermal response, and tritium permeation. We have concluded that a tungsten-coated, copper substrate plate offers the possibility of low erosion coupled with good thermal properties. However, there are many unresolved issues with this and other plate configurations. These issues include the transfer of first wall sputtered material to the plate, tritium permeation into the coolant, and mechanical problems such as radiation swelling and embrittlement.