High heat flux testing of ITER ICH&CD antenna beryllium faraday screen bars mock-ups

• Published in: Fusion engineering and design 2016-11, Vol.109-111, p.371-376
• Main Authors: Courtois, X., Meunier, L., Kuznetsov, V., Beaumont, B., Lamalle, P., Conchon, D., Languille, P.
• Format: Article
• Language: English
• Subjects: Beryllium; Faraday Screen; High heat flux test; Non destructive examination; Plasma facing component
• ISSN: 0920-3796; 1873-7196
• DOI: 10.1016/j.fusengdes.2016.02.096

•ITER ICH&CD antenna beryllium faraday screen bars mock-ups were manufactured.•The mock-ups are submitted to high heat loads to test their heat exhaust capabilities.•The mock-ups withstand without damage the design limit load.•Lifetime is gradually reduced when the heat load is augmented beyond the design limit.•Thermal and mechanical behavior are reproducible, and coherent with the calculation. The Faraday Screen (FS) is the plasma facing component of ITER ion cyclotron heating antennas shielding. The requirement for the high heat exhaust, and the limitation of the temperatures to minimize strain and thus offer sufficient resistance to fatigue, imply the need for high conductivity materials and a high cooling flow rate. The FS bars are constructed by a hipping process involving beryllium tiles, a pure copper layer, a copper chrome zirconium alloy for the cooling channel and a stainless steel backing strip. Two FS bars small scale mock-ups were manufactured and tested under high heat flux. They endured 15,000 heating cycles without degradation under nominal heat flux, and revealed growing flaws when the heat flux was progressively augmented beyond. In this case, the ultrasonic test confirms a strong delamination of the Be tiles.