[570] VESPA BERYLLIUM FILTER SYSTEM

The Beryllium Filter System is a component of the VESPA neutron spectrometer in construction at the ESS. The filter system is constituted of wedges of beryllium intercalated with sheets of cadmium, which also clads the outer faces not in the neutron beam path (top, bottom, sides). The purpose of the filter system is to suppress high energy neutrons (> 5 meV, scattered by the beryllium wedge and absorbed by the cadmium), while letting low energy neutrons (< 5 meV) through. The filter system needs to be delivered assembled. 4 units of filters are required.