Prevention of Yb adsorption by paraffin coating

Ytterbium (Yb) is used in cold-atom systems, including magneto-optical traps and optical lattice clocks. However, the long-term operation of such systems may be associated with substantial degradation of optical transmittance through vacuum chamber viewports due to Yb adsorption. Here, we show that coating the surface with tetracontane effectively suppresses such adsorption.