*A beam enclosure has been constructed to shield observers from harmful UV light. It is made from Poly(methyl methacrylate)which filters 193nm light very well as shown by the following ([http://www.gclabsite.com/files/publication/gc47_p28.pdf graph]). | *A beam enclosure has been constructed to shield observers from harmful UV light. It is made from Poly(methyl methacrylate)which filters 193nm light very well as shown by the following ([http://www.gclabsite.com/files/publication/gc47_p28.pdf graph]). |