The OSIRIS instrument at the ISIS Neutron and Muon Source is specialised for low-energy neutron spectroscopy and is being upgraded with a silicon analyser as part of the Endeavour programme.

It will measure small energy transfers with high precision and, from this, new information about the mobility of ions, atoms and molecules can be derived.

The Composites and Materials Testing Group in Technology were given the task of building the silicon analyser in collaboration with ISIS.

In total, the analyser features four upper and four lower spherical aluminium plates, all machined in our Manufacturing Facilities workshop, covered with 2m2 of silicon wafers.

Each silicon wafer was carefully inspected for any scratches or defects before being spray-coated with Gd2O3.

They were then cut with a diamond wire saw and glued under elastic deformation into position on the panels under vacuum for two hours.

After this, the panels were dimensionally checked in our Metrology Facility for compliance with demanding drawing tolerances using one of our precision coordinate measuring machines (CMMs).