Speaker
Description
The design, development, and upgrade of vacuum components for current and future particle accelerators requires a thorough qualification of all dynamic processes that lead to pressure increments during beam operation. Knowing the amount of deposited energy on the vacuum materials that needs to be extracted by the cooling system, and the related thermal material surface effects, is essential. In addition, especially electron-, ion- and photon-induced desorption and emission of secondary particles processes require to be quantitatively understood to model potential pressure loads to the vacuum system and to properly design the required pumping equipment and interlock system. The mentioned phenomena must be characterised experimentally at conditions that are close to the operational ones. The beam screen test bench experiment (BESTEX) setup at KARA contributes one ingredient for the development of new vacuum designs for the Future Circular Collider (FCC) and the selection of best suited materials and functional surface treatments: exploration of photon-induced processes. I will summarise the past activities of photon-stimulated desorption (PSD) studies for the FCC-hh beam screens as well as measurements of different surface functionalisation. Furthermore, the technical challenges and solutions for the fabrication of FCC-ee prototype chambers will be described together with a description of the requirements and plan of future PSD measurements for FCC-ee relevant conditions. Finally, the adaption of the experimental setup to allow for photoelectron yield (PEY) measurements will be described.