Speaker
Description
The mirrors of the low frequency interferometer of the Einstein Telescope will be cooled to cryogenic temperatures in order to mitigate thermal noise. At these temperatures residual gas freezes onto the mirror, forming a layer of ice. This icy layer will affect the sensitivity but also the cooling power of ET. Hence R&D measurements at cryogenic temperatures are conducted. These measurements include the in-situ monitoring of ice formation on the mirror with spectroscopic ellipsometry and in a future extentsion with quartz crystal micro balance, as well as the cross-calibration of both methods. Additionally, vacuum conditioning methods such as UV-cleaning, argon plasma cleaning and ozone cleaning can be tested at the Vacuum, surface monitorIng aNd Cleaning ExperimenT (VINCENT) at KIT. The poster will describe the methods developed together with other institutions and presents first measurements of ice growth on a silicon die with spectroscopic ellipsometry.