1. SCT Barrel 6 Support Bearing A full-scale model of the barrel 6 support bearing has been machined at UCL (drawing G.Barbier ) It was tried out on both the 360 deg. End Barrel model and the 4 Barrel assembly model. Comments: LMTs - the gaps for the LMTs are just less than 21mm across at the narrowest part, so tapes don’t fit neatly. This part should be shaped with the same dimensions as the end barrel tape clamp recess. An inner surface made of PEEK, bonded to the inner radius of the bearing (same dimensions as end barrel LMT clamp) would serve as an efficient strain-relief clamp for the tapes when the bearing is screwed down to the barrel surface. For this reason, the bearing should be in place immediately after harnesses are installed - if possible, otherwise use temporary clamps.

2. Readout FIBRES - 4 sets have to be routed on the bearing. 2 away from the horizontal interlink in one direction and two away in the other direction. Space is very tight - the 36 fibres (single - sleeved) will only just fit in so it would be preferable to have more space here. The fibres will need to be fastened in position with small clips - again similar to those used on the end-barrel clamps. The bearing will have to have screw holes for these clips. Bearing edges need a radius where fibres pass over. HARNESS INTERLINKS - there will have to be two special longer interlinks at each end in the bearing area unless they can pass underneath the inner surface of the bearing. They would have to be approx. 10mm longer in order to go over the bearing screw area. THERMAL ENCLOSURE - does the top edge of the interlink bracket clear the thermal enclosure radius? Need drawing.

3. COOLING units - On the 360 deg model we can see that the cooling manifold and the return are extremely close to the bearing. Need to work out exact clearances to make sure there is no clash when cooing units are installed. The cooing manifold connector position on the model is very close to the bearing- need to check if this is still true on the RAL drawings. ALIGNMENT - the light path tube on the model lies directly under the place where the bearing would be screwed down onto the flange. Need to check if the alignment item can be moved or the light path shortened here. Check drawings.