ARTOSS – A new surface science experiment to study the hydrogen inventory in multi-component materials

Abstract

The design of a new instrument is described along with results demonstrating the capabilities of in situ preparation and analysis. The purpose of the ARTOSS experiment is the preparation and analysis of multi-component surface layers on materials – in particular those which are well-suited for the first wall of present and future fusion devices – and their behaviour with respect to the hydrogen inventory in such materials. Relevant preparation and analysis techniques are combined to achieve this aim. For preparation, surfaces can be cleaned in situ and layer preparation includes vapour deposition, ion beam bombardment at energies between 100 eV and 20 keV as well as admission of gases. Photoelectron spectroscopies analyse the chemical state of elements within the surface layers, ion beam techniques enable quantitative measurements, including hydrogen isotope analysis. For ion beam analysis, low-energy (up to 5 keV) as well as high-energy ions (3 MV tandem accelerator) are available in situ. Thermal desorption and re-emission measurements complete the capabilities for hydrogen detection in multi- component materials. Sample transfer into the ultra-high vacuum system is possible via a sample load-lock. Results are presented for carbon layers on beryllium and surface modifications of beryllium by C+ and CO+ ion bombardment to demonstrate the capabilities of the new experiment.