Wall conditioning in TCSU and its effect on plasma performance

Abstract Translation, Confinement, and Sustainment Upgrade (TCSU) is a large Field Reversed Configuration (FRC) experiment in which the plasma is created and sustained in quasi-steady state by a transverse rotating magnetic field. It was built to ultra-high vacuum (UHV) standards and employs baking, H 2 and glow discharge cleaning (He-GDC) to clean the first wall. In addition, both siliconization and titanium evaporation have been used to further condition the wall. In order to better understand the interaction between plasma and first wall, the TCSU surface analysis system was developed. An overview of the surface-analysis studies is given in the present study, along with some highlights from the experimental results. The correlation of wall conditioning techniques with TCSU plasma performance is also discussed.