Progress in the production of the W7-X divertor target modules

Abstract

The realization of the 19.6 m² highly heat loaded target area of the actively water-cooled divertor of Wendelstein 7-X (W7-X) requires the installation of 100 target modules distributed in ten discrete similar divertor units. A target module is water-cooled from manifolds to distribute the water equally between the target elements with flanged connections to the water supply system. A target element is made of a CuCr1Zr copper alloy heat sink armored with CFC NB31 tiles and designed to remove a stationary heat flux up to 10 MW/m². The production of the first 30 target modules has been successfully completed in the workshop of IPP-Garching. The quality of the finished target modules was systematically assessed as follows: visual inspections, measurement of the 3-D CFC target area, dynamic pressure tests, integral He leak testing under pressure at different conditions (20 °C, 4 MPa and 160 °C, 2.5 MPa) in a vacuum oven, high heat flux testing. Only 2 finished target modules did not pass the integral He leak testing and were successfully repaired.