Discharge Chamber Plasma-Chemical Conditioning in Magnetic Confinement Fusion Devices (Review)

Plasma-chemical deposition of a protective coating on the first wall of a fusion device using a chemically active gas (precursor) remains to date one of the primary ways to protect the plasma against cooling impurities. This method has proved effective and does not require the use of additional and expensive equipment. The process in which a boron-containing gas is used as a precursor is referred to as boronization. This paper considers various aspects of using carborane for boronization, including the structure and properties of resultant boron-carbon films; results of boronization for different fusion devices and different precursors; effect of boronization on working plasma pulses; boronization in a low-temperature glow discharge plasma as compared to that in a high-temperature plasma of fusion devices at working pulses with ohmic, ECR, and ICR plasma heating; and the possibility of using boronization during operation of fusion devices.

Automated summary

Plasma-chemical deposition of a protective coating using a chemically active gas remains a primary method to protect the plasma in fusion devices. Boronization, utilizing a boron-containing gas as a precursor, is an effective and widely used technique discussed in this paper. The study covers the structure and properties of resulting boron-carbon films, effects on different fusion devices, and the potential use of boronization during operation.