Industrial scale 10 μm W coating of CFC tiles for ITER-like Wall Project at JET

As a result of the R&D phase of the ITER-like Wall Project, combined magnetron sputtering and ion implantation (CMSII) technique was selected for 10 μm W coating of approx. 1000 CFC tiles for the new JET first wall. This technique involves simultaneous magnetron sputtering and high energy ion bombardment. A high voltage pulse discharge is superposed over the magnetron deposition and by this way positive ions are accelerated, bombarding initially the substrate and then the coating itself during its growth. Based on this method, industrial equipment with a deposition chamber of Φ800 mm × 750 mm and 24 magnetrons was designed, manufactured and commissioned. The coating productivity is about 1 m2/week. Tungsten coatings with a thickness of up to 17 μm and multilayer structures Mo/W/Mo/W with a thickness of ∼25 μm were produced and successfully tested at 100 pulses of 16.5 MW/m2 for 1.5 s.