Speaker
Description
The Apparatus for Surface Physics and Interfaces at CERN (ASPIC) was previously installed in the solid-state physics section of the ISOLDE experimental hall, where it operated under ultra-high vacuum conditions (UHV, $\leq 10^{-8}$ mbar). ASPIC enabled studies of metallic surfaces, magnetic thin films, and interface dynamics, and supported experiments using radioactive isotopes and a range of thin-film fabrication and modification techniques. ASPIC is no longer in regular operation at the GLM area, and its development informed the design of the follow-up system.
The Apparatus for Surface Physics and Interfaces at CERN's Ion Implantation Chamber (ASCII) represents this next-generation setup and is currently under commissioning. It is designed for tunable ultra-low-energy implantation ($\gtrsim 20$ eV) of radioisotopes in UHV conditions down to $\leq 10^{-9}$ mbar. The system enables implantation depth control on the order of a few angstroms and precise placement of probes such as $^{111\text{m}}$Cd and $^{204\text{m}}$Pb into materials ranging from two-dimensional systems (graphene, transition-metal dichalcogenides) to (multi)ferroic compounds, nanoparticles, and topological insulators. A first demonstration of $^{111}$Ag implantation using ASCII was successfully performed at the Universität Göttingen.
The current commissioning and integration work includes the design of an additional differential vacuum chamber (DVC) to ensure UHV integrity within the ASCII chamber itself, as well as engineering measures to meet CERN safety requirements. These measures include a floating equipment cabinet, a rack with segregated power supplies with approved interconnections, and an integrated Faraday cage for the chamber, which handles grounding and electromagnetic shielding. Ongoing tasks concentrate on completing the DVC and vacuum system installation, validating implantation procedures, verifying electrical and grounding arrangements, and finalising the safety interlocks and approvals required for radioactive-ion operation. Once fully commissioned, ASCII will be available to the ISOLDE community as a versatile tool for investigations of surfaces and interfaces in solid-state nuclear condensed-matter physics.