Rapid Cleaning of Boronized Walls with a Chlorine/Hydrogen Glow Discharge

Abstract
Chlorine/hydrogen discharge cleaning was developed to remove boron films coated on walls of nuclear fusion devices. The removal rate of boron films (∼0.1 Å/s) was an order of magnitude faster than that obtained by conventional hydrogen discharges. Mass spectroscopic measurement revealed that BCl3 is a main volatile product in the removal process. Chlorine contaminants after film removal were cleaned up by additional hydrogen discharges.