Surface analysis studies in the Translation, Confinement, and Sustainment Upgrade (TCSU) experiment

Plasma-wall interactions have been a crucial issue in controlling hydrogen recycling and impurity ingestion in magnetically confined plasmas. A dedicated surface analysis system with UHV sample transfer capability proved to be extremely useful in understanding some of the fundamental plasma-material interaction mechanisms in the new Translation, Confinement and Sustainment Upgrade (TCSU) experiment. This thesis presents the surface analysis studies carried out during the first two years of TCSU operation. The basic design considerations, tools and capabilities of the surface analysis system will be discussed.;Previous experience with the Translation, Confinement and, Sustainment (TCS) experiment demonstrated that radiation due to plasma impurities was among the major factors limiting plasma performance. To minimize radiation-loss effects, TCSU has been built with the major goal of minimizing impurity ingestion into plasma. Accordingly, considerable effort was put in the ex-situ preparation of vacuum facing surfaces of TCSU, and in-situ wall conditioning techniques including glow discharge cleaning (GDC), Ti-gettering and siliconization has been implemented. The surface analysis system was effectively utilized for the following tasks: establishing surface preparation protocols for TCSU components, studying the evolution of wall surfaces during routine TCSU operation, and studying and assessing the effect of wall-conditioning techniques.