Photo reflectivity and photo electron yield from technical surfaces

The knowledge of material properties is an essential stepto design particle accelerators and High Energy Colliders.During operation of these machines, the walls of the vac-uum chambers are subjected to bombardment of photonsand electrons. The detrimental interactions may be followedby issues related to vacuum and beam instability. Hence,it becomes crucial to obtain experimental data about theseinteraction in conditions as close as possible to the operativeones. Among others properties, Reflectivity ( both specu-lar and total component) and photoyield are of particularinterest. These data will be used in numerical simulationsto design vacuum systems. In an experimental campaign,carried out at the OPTICS beamline of BESSYII, we inves-tigated the Reflectivity and the Photon Yield of technicalmaterials of interest for the High Luminosity LHC upgradeand Future Circular Collider-hh design.