Dan Cheng, Helene Felice 4/8/2015 MQXFS-D Build-up LBNL “Lessons Learned”

Outline 4/8/2015MQXFS-D Build Up, LBNL2 Build Process Notes, and Lessons Learned – Yoke-shell subassembly – Coil pack builds – Preload and axial loading operations – Cable packaging

Yoke-Shell Subassembly 4/8/2015MQXFS-D Build Up, LBNL3 Only one yoke quadrant was axially aligned with pins; only one end of the other three yoke quadrants was pinned CERN Yoke handling tooling was not approved for use by LBNL safety in time for assembly (did not need it in the end…) High pressures (6, ,000 psi/40 – 48 MPa) were required – Encountered some bladder failures after reaching these pressures => We plan to redesign tooling to incorporate 8 bladder slots instead of 4 in this initial tooling design (CERN is also exploring this as well)

Coil GPI 4/8/2015MQXFS-D Build Up, LBNL4 Did not actually use our coil rotating tooling (yet) – Some modifications will still need to be implemented before real coils – Kapton with B-stage layer will be ordered to the correct width (so we don’t have to trim to size) Coil alignment key was machined undersized, required 0.037” additional per side (or almost ~2 mm total in additional thickness) => Will size future keys to reduce amount of additional shims required

Coil & Collar Shims 4/8/2015MQXFS-D Build Up, LBNL5 Collar required ~0.057 (~1.5 mm) thick of shim (G10), not including GPI layers – We will adjust collar radius in long model to use less shim Collar laminations appear to have been made differently for each type of stack (tapped vs. slotted holes) – Slight difference in lamination thickness between styles was evident when all stacks were assembled together—offset in the holes observed end to end

Load Pad Key Fit 4/8/2015MQXFS-D Build Up, LBNL6 Load pad key feature on two pads (with slot features) initially did not fit the collar key slot – Fabricated a “go, no-go” gauge and dressed the key on the pads in order to fit them in the collars Load pads with tapped holes fit the collar slots

Coil Pack Builds 4/8/2015MQXFS-D Build Up, LBNL7 Tapped holes in collars also did not appear to be fully chased – A few aluminum metal chips were found on Kapton GPI after collar pack build was complete Fortunately we are not powering this structure… A few tapped holes in load pads needed chasing as well

Master Key Shims 4/8/2015MQXFS-D Build Up, LBNL8 Alignment and load keys required lots of shim in nominal dimensions – Each load key required 0.120” (~3 mm) thick worth of shims to start – Alignment keys required ~2 mm per side of shims (still with clearance) – We plan to increase nominal thickness of these keys to reduce shims needed Holes in shim stock (for the pins in load keys) – A few had burrs that made insertion difficult in the early operations – While there are benefits, we may or may not use this feature in future builds Load keys – Mild steel on mild steel master key surfaces seemed to gall (even with Moly disulfide)

Axial Loading Preparations 4/8/2015MQXFS-D Build Up, LBNL9 Threaded holes on axial endplate creates some issues – Not all rods could be screwed in the same amount (due to SG placement requirements) – Rods were not necessarily placed optimally in its space (may need additional tooling/spacers) “Best effort” placed at a nominal position Coil size variances may cause this load pad gap size to vary by a small amount from structure to structure

Axial Loading Preparations 4/8/2015MQXFS-D Build Up, LBNL10 Spherical washers – CERN spec’ed a washer with a different thickness than the ones we obtained. – Stack height was ~12 mm vs ~23 mm designed height – Rod threads bottomed out, so we spaced the LE end plate ~44 mm instead of 35 mm nominal

Wire Routing 4/8/2015MQXFS-D Build Up, LBNL11 IL wiring (including SGs) – Initial design called for IL signal wires to pass through bore opening (OL would pass around endplate) – We opted to route wires as we have in prior LARP magnets (eg. IL and OL wires pass around endplate) – Future builds may still pass IL wires through bore (still in discussions during connection box design process)

Completed MQXFS-D 4/8/2015MQXFS-D Build Up, LBNL12