ICRF siliconization in HT-7 superconducting tokamak

A new wall-conditioning method, ICRF plasma-assisted coating with silicon film, the so-called RF-siliconization, has been developed in HT-7 superconducting tokamak. It leads to suppression of carbon and oxygen impurities effectively. The properties of deposits were investigated by X-ray photoelectron spectroscopy (XPS). Silicon atoms have a large sticking probability on the wall and are practically less recycling. Plasma performance has been improved after ICRF siliconization.