29th Symposium on Fusion Technology (SOFT 2016)

P4.101 High heat flux testing of newly developed tungsten components for WEST

Sep 8, 2016, 2:20 PM

1h 40m

Foyer 2A (2nd floor), 3A (3rd floor) (Prague Congress Centre)

Board: 101

Poster F. Plasma Facing Components P4 Poster session

Speaker

G. Pintsuk (Forschungszentrum Jülich GmbH)

Description

The WEST (W -for tungsten- Environment in Steady-state Tokamak) project is based on an upgrade of Tore Supra tokamak. ITER-like actively cooled tungsten targets (monoblocks) will be integrated in the lower divertor and a new set of actively cooled tungsten coated plasma facing components will cover a part of the vessel to provide a fully metallic environment. In preparation of the production of the actively cooled tungsten targets for the lower divertor the qualification of suppliers is done by exposing small-scale mock-ups to cyclic high heat flux tests in the electron beam facility JUDITH 1 at Forschungszentrum Jülich. Thereby, the small-scale mock-ups are based on the ITER design, consisting of 7 monoblocks mounted on a CuCrZr cooling tube and connected via a soft Cu-interlayer. The results presented herein focus on the high heat flux test results of two mock-ups produced by ASIPP in China. The testing was performed by thermal cycling at 10 MW/m²2 and at 20 MW/m²2. While for the first component failure occurred after 769 cycles at 10 MW/m²2 due to accidental conditions in the testing facility, the second component, being pre-exposed on two blocks to 700 cycles at 10 MW/m²2, survived 500 additional cycles at 10 MW/m2 and up to 500 cycles at 20 MW/m²2 without obvious damage formation. The discussion of the results comprises the thermal performance of the mock-ups during thermal cycling in relation to the initial qualification via infrared thermography facility SATIR at CEA-Cadarache, the tungsten thickness as well as the subsequent microstructural analyses. The latter focus on the most important issues determined in earlier studies on ITER qualification mock-ups and components, i.e. tungsten recrystallization and macro-crack formation, the integrity of the CuCrZr cooling tube, and plastic deformation induced changes in the pure Cu-interlayer.