The coating plant for the segments of the primary mirror of the Extremely Large Telescope (ELT) in Chile

The coating plant for the M1 primary mirror segments of the Extremely Large Telescope (ELT) currently under construction in Cerro Armazones, Chile by the European Southern Observatory (ESO) will deposit a highly reflective protected-silver-based coating by magnetron sputtering technology. This paper describes how AGC Glass Europe SA, through its business unit AGC Plasma Technology Solutions, realized the design and manufacture of a highly automated coater based on its experience in building large area architectural glass coaters. In addition, some results of pre-acceptance testing in Lauenförde, Germany are reported.