Overview of the new IGNIS-2 surface science facility for the in-situ analysis of fusion plasma-facing components at Penn State

The IGNIS-2 in-situ surface science facility is a new experimental platform that will be utilized for the analysis of plasma-facing components (PFC). This overview will discuss the design and commissioning of IGNIS-2, and ongoing projects which utilize the facility's unique capabilities to study reconstituted materials and liquid metal-surface interactions for PFC development. IGNIS-2 will utilize broad-beam ion sources to modify the surface of materials while simultaneously measuring the evolution of the surface properties. This new facility will continue to feature Low Energy Ion Scattering Spectroscopy and X-ray Photoelectron Spectroscopy (XPS) to measure chemical composition at the surface and in the near-surface region, while a major upgrade to a monochromatic X-ray source will greatly improve the resolution of XPS measurements. The new facility will also incorporate optical techniques, such as Multi-beam Optical Stress Sensor and Ellipsometry, to make in-situ measurements of surface stress, film thickness, and surface roughness. The main analysis chamber will be connected to other chambers through a series of in-vacuo components, allowing samples to be moved to chambers dedicated other purposes such as thin-film deposition via evaporation or magnetron sputtering. A major research activity on IGNIS-2 is the study of liquid lithium films on nanostructured porous tungsten substrates, supporting work on the NSTX-U spherical tokamak. Another major focus of research on IGNIS-2 is the study of reconstituted boron/tungsten layers, as would be found in a fusion reactor with tungsten PFCs and boron wall-conditioning due to continuous erosion and redeposition of material at the surface of PFCs.