Active control over carbon deposition by gas feeding for the protection of diagnostic the mirrors in ITER

作者：Matveeva M^*; Litnovsky A; Marchuk O; Schulz Ch; Moeller S; Wienhold P; Philipps V; Stoschus H; Samm U

来源：Physica Scripta, 2011, T145: 014072.

DOI：10.1088/0031-8949/2011/T145/014072

Deposition of impurities can drastically change optical properties of metallic mirrors used for diagnostics of fusion plasmas. Specifically in ITER, this can become critical for the reactor operation by affecting the quality and reliability of detected signals. A series of experiments was performed in TEXTOR where local gas feeding was used for mitigation of carbon deposition on the mirror surface. A prototype of a diagnostic duct with molybdenum mirrors equipped with a gas feeding system was exposed in scrape-off layer plasma under deposition-dominated conditions. In the case of helium feeding, suppression of deposition was observed, while feeding of deuterium not only demonstrated full suppression of deposition but even favored complete removal of initially pre-deposited a-C: D layers. This paper presents results of experiments along with dedicated modeling of plasma-gas interaction inside the diagnostic duct.

• 出版日期2011-12