Fusion Science and Technology / Volume 60 / Number 1 / July 2011 / Pages 218-222
Divertor & High Heat Flux Components / Proceedings of the Nineteenth Topical Meeting on the Technology of Fusion Energy (TOFE) (Part 1)
This paper considers a combination of ARIES modular finger concept and a design with helium channels in a thick plate. Multiple-jet cooling at a back side of a plasma facing surface is employed in this concept. The plasma facing surface is subdivided into a large number of small hexagonal modules, similar to the EU finger concept. Such a modularization reduces thermal stresses and allows therefore maximum surface heat flux of 10 MW/m2 at least. A solution has been found allowing brazing the fingers made of a W-alloy directly into the W-plate, avoiding in this way the connection of dissimilar materials with largely different thermal expansion coefficients. For an increase in reliability, double walled thimbles are used in the most critical region, providing an additional barrier against leaks of the high pressure helium. Thermal-mechanical calculations confirmed the expected high performance of the concept with the maximum allowable heat flux > 10 MW/m2 with all the components staying in the elastic regime. Extensive analyses of non-linear materials responses, such as plastic deformation (yield) are performed to allow the materials to be pushed beyond 3Sm in order to determine the maximum allowable heat flux can be.