ARRIBA: A Novel In-Situ Plasma Surface Interaction Diagnostic

The plasma boundary interface plays a critical role in the performance of magnetic fusion experiments. Plasma surface interactions (PSI) lead to erosion, deposition, and tritium retention processes at material surfaces. The effects of these processes pose significant operational and safety hazards, ultimately affecting fusion¿s viability as an energy source. Real-time in situ measurements of PSI are necessary to reliably predict erosion, deposition, and tritium retention in present devices, and to confidently extrapolate present results to future burning plasma experiments (e.g. ITER) and reactors. This project will evaluate the feasibility of an Alpha Radioisotope Remote Ion Beam Analysis diagnostic (ARRIBA) for use in magnetic fusion devices. The ARRIBA will provide in situ time-and-depth-resolved measurements of element concentrations, net erosion and deposition, and H/D/T (hydrogen/deuterium/tritium) fuel retention at any surface inside a magnetic fusion device ¿ including surfaces exposed to significant heat loads, such as the divertor. Although initial evaluations suggest that the ARRIBA provides adequate erosion/deposition resolution and hydrogenic sensitivity for tokamak PSI studies, more detailed analysis and experimental verification are needed to more fully understand the underlying physics. An ARRIBA prototype will be developed in Phase I. Phase II will involve further optimization of diagnostic performance for magnetic fusion devices. Commercial Applications and other Benefits as described by the awardee: In addition to the application to magnetic fusion, the ARRIBA diagnostic should find use in the semiconductor and plasma processing industries.