Development of W coatings for fusion applications

Properties of Electrodeposited Tungsten Coatings on Graphite Substrates for Plasma Facing Components

“…Due to the advantages of high melting point (the highest among the metals), good thermal conductivity and high physical sputtering threshold energy, et al tungsten has been considered as the main candidate materials for PFCs [1,2]. However, the critical issues of tungsten block, such as heavy weight, poor machining processing and high ductile-brittle transition temperature (DBTT), restrict its further applications.…”

Development of CVD-W coatings on CuCrZr and graphite substrates with a PVD intermediate layer

“…Moreover, a W coating has higher Ohmic resistance than bulk W, which can reduce eddy currents. For present day fusion devices with low particle fluences, a W coating, therefore, is considered an effective way to fabricate the PFCs of the first wall or divertor [6][7][8]. Even for the first wall of DEMO, where the heat load under normal operating conditions is around 2 MW/m 2 , a protection layer consisting of W on the structural materials might be an option [2].…”

“…In the ITER-like Wall Project at JET and ASDEX Upgrade, more than 2500 CFC tiles with W coating (10-15 lm and 20-25 lm) deposited by a combined magnetron sputtering and ion implantation technique was applied successfully. In order to compensate the thermal expansion mismatch between CFC and W, a 2-3 lm thick molybdenum (Mo) interlayer was used [7].…”

“…In this case, the heat flux pulse is high and the pulse duration is short. PVD-Mo was used as an intermediate layer between PVD-W and CFC in the ITER Like-wall Project at JET [7,19]. The application of a PVD silicon (Si) layer as the transition layer between a graphite substrate and VPS-W showed good properties in a high heat flux test [20].…”

Tungsten coatings under high thermal loads in JET and Magnum-PSI

“…As far as long pulse thermal loading is concerned high heat flux (HHF) tests have been carried out on W coatings in the GLADIS hydrogen beam facility (IPP Garching) during the qualification and production phases of the ILW project [2]. Additional tests have been performed with the electron beam high temperature test facility at NILPRP, Bucharest with the aim to investigate the limits of these W coatings for a large number of heating cycles [3]. ELM-like simulations tests with duration of ~ 1 ms were carried out on the same type of W coatings in JUDITH 1 and JUDITH 2 facilities at FZ Jülich [4].…”