The Aluminizing Plant

The plant was produced by Balzers of Liechtenstein who subcontracted the large vacuum vessel to Grazebrook Limited, a UK firm. The plant was installed in the WHT plant room and the commissioning tests successfully carried out. During the aluminizing process, a total of 63 g of aluminium is evaporated, 3.5 g being desposited on the 13m² surface of the primary mirror to create a reflective surface 100 nm thick. The power consumption of the plant rises to 85 KVA for the 90 seconds duration of the evaporating stage. Mirrors are aluminized once a year or year and a half.