Dan Cheng QXF Structures Working Group November 7, 2014 Implications for the split-shell MQXFS concept

Outline 11/7/2014Implications of MQXFS split shell concept2 Proposed change Fabrication implications Assembly process implications

11/7/2014Implications of MQXFS split shell concept3 Proposed shell length concept Segmented shell concept may change, based on analyses on coil stress variations – Two equal-length segments may not be adequate – “1-2-1”: One ½-length segment between ¼-length segments on each end How does this affect our fabrication and assembly procedures?

11/7/2014Implications of MQXFS split shell concept4 Proposed shell cut changes Requires one existing shell to be cut in half – Cut ends of split shell segments may need end features machined Tapped holes necessary Pin slots optional? <= Decision Point Tapped holes, 4 loc. req’d

Split SQXF shell operations 11/7/2014Implications of MQXFS split shell concept5 Shell fabrication – Shell cut into half: ~$2.5k in labor and materials; ~1 week lead Will lose approximately 4 mm total length (~2 mm per cut shell piece) Includes tapped holes into the cut faces of shells (pin slots optional) <= Decision point Possible re-CMM cut ends of shells <= Decision point – Re-CMM the shell (~1 week) Examine the cut ends if shape/structure significantly changed? <= Decision point – Re-instrument shell segments, ~2 weeks Locations of new SG stations TBD <= Decision point

Yoke implications of split SQXF shell 11/7/2014Implications of MQXFS split shell concept shell concept will position shell cutouts in the wrong locations, with respect to the yoke laminations – 12 mm offset from each end Options to address this issue <= Decision point – Do nothing; don’t use welding block features in future – Re-assemble yoke lamination stacks with offsets? Yoke stacks will likely lose their machined surface registrations – Drill and tap new locations for the welding block locations without restacking This will change two-bolt patter of welding block 2 locations

Assembly implications of split SQXF shell 11/7/2014Implications of MQXFS split shell concept7 Requires additional assembly “pin retainer” assemblies for the 2 nd shell joint 2 nd joint also requires additional clamping bars/straps to hold shells together prior to yoke insertion No other tooling or process changes seem to be required

Summary of split SQXF shell Implications 11/7/2014Implications of MQXFS split shell concept8 Shell fabrication – Shell cut into half: ~$2.5k in labor and materials; ~1 week lead Includes tapped holes into the cut faces of shells (pin slots optional) Will lose ~2 mm off each cut shell piece Possible re-CMM cut ends of shells (~1 week) – Re-instrument shell segments, ~2 weeks Yoke stacks – Do nothing; precludes use of welding blocks in the future – Possibly rearrange the yoke lamination with offsets (has other implications) – Drill and tap new locations for the welding blocks Assembly implications – Aside from the pin retainers and banding, no additional tooling seems to be necessary