MQXF Workshop on Structure, Alignment, and Electrical QA Feb 2-4, 2016 Dan Cheng J. De Ponte, H. Felice, S. Kincaid, T. Lipton, S. Myers, A. Pekadis, M. Reynolds, J. Taylor, X. Wang, and many others Lessons Learned from the MQXFS Assembly Processes

Outline Feb 2, 2016MQXFS Assembly Lessons Learned2 Lessons learned on preassembly steps Lessons learned magnet integration steps Lessons learned on magnet instrumentation and connectors Summary

Outline Feb 2, 2016MQXFS Assembly Lessons Learned3 Lessons learned on preassembly steps Lessons learned magnet integration steps Lessons learned on magnet instrumentation and connectors

MQXFS Yoke-Shell Subassembly Feb 2, 2016MQXFS Assembly Lessons Learned4 High bladder pressures (6, ,000 psi/40 – 48 MPa) were required for the initial assembly – Encountered some bladder failures after reaching these pressures For MQXFA we redesigned tooling to incorporate 8 bladder slots instead of 4 in this initial tooling design

Application of MQXFS Coil GPI Feb 2, 2016MQXFS Assembly Lessons Learned5 MQXFSD coils had Kapton with B-stage layer that had to be trimmed to size from larger sheets/rolls MQXFS1 coils used Kapton with B-stage layer ordered to custom width; no additional trimming is necessary, MQXFA will be using the same material

MQXFS Collars and Load Pads Feb 2, 2016MQXFS Assembly Lessons Learned6 MQXFS Collar required ~0.057 (~1.5 mm) thick of shim (G10), not including GPI layers For MQXFA – Collar radius was reduced by 1 mm to require less shimming (and less labor) to process – Collar radial shim will also use a custom width roll of Kapton to fold around the collar (again, no additional trimming necessary) Was 115 mm

Improved Coil Support Spud Feb 2, 2016MQXFS Assembly Lessons Learned7 After the disassembly incident of MQXFS1, coil pack procedures and tooling were adjusted The redesigned coil support spud was incorporated into the use of MQXFS1 coil pack builds #3-5 – Screws positively engage with each coil to prevent relative motion This tooling will continue to be used for MQXFA

MQXFS Coil Pack Builds Feb 2, 2016MQXFS Assembly Lessons Learned8 There are still some chips that are being generated by the screwing/unscrewing process of the aluminum collars MQXFA tooling has been designed for Load Pad stacks and Collar stacks to be preassembled together, and only load pads (SST/steel) would be bolted – CERN has already tested this option in their short model with promising results – This will also be more compatible with thin-laminated component stacks – This will also reduce the labor required for each coil pack assembly step Courtesy: N. Bourcey

Lessons Learned Preassembly Steps Feb 2, 2016MQXFS Assembly Lessons Learned9 Improving reliability – Reducing pressures applied improve bladder reliability – Coil support spud positively engages with the coils during the coil pack assembly and disassembly processes Improving efficiency – Purchasing custom width rolls of Kapton saves time and labor in preparation – Assembling load pad and collar stacks together, and using fewer bolts will significantly reduce time required in the coil pack assembly/disassembly steps

Outline Feb 2, 2016MQXFS Assembly Lessons Learned10 Lessons learned on preassembly steps Lessons learned magnet integration steps Lessons learned on magnet instrumentation and connectors

MQXFS1 Coil Pack Insertion Rails Feb 2, 2016MQXFS Assembly Lessons Learned11 Coil pack was inserted into the shell & yoke assembly with the insertion rails Rails were removed when bladders were first cycled This design will be retained for MQXFA

MQXFS1 Master Keys & Shims Feb 2, 2016MQXFS Assembly Lessons Learned12 MQXFSD Alignment and load keys required many shims at nominal conditions MQXFS1 keys were increased in thickness – 1 mm per each load key half, and 2 mm in alignment key – This reduced the amount of shim required during bladder operations For MQXFA “process keys” will be employed: sets of full-thickness single keys to be made ”, ”, ”… thicker than nominal for the loading sequences – This removes the need to add shims during loading/unloading sequences

Lessons Learned Integration Steps Feb 2, 2016MQXFS Assembly Lessons Learned13 Steady progress was made in the key shimming processes of bladder operations – From MQXFSD to MQXFS1 the keys were sized to reduce the amount of thin shims required – From MQXFS1 to MQXFA, “process keys” will be introduced to reduce further the time/effort of shimming the keys for each bladder step

Outline Feb 2, 2016MQXFS Assembly Lessons Learned14 Lessons learned on preassembly steps Lessons learned magnet integration steps Lessons learned on magnet instrumentation and connectors

Splices and Connections Feb 2, 2016MQXFS Assembly Lessons Learned15 MQXFS splice connections made in the two-layer package had no particular issues Connector packaging density, however, is at the limit for the number of signals for MQXFS1 – More signals in MQXFA may require a different packaging scheme

Instrumentation Wiring for MQXFS1 Feb 2, 2016MQXFS Assembly Lessons Learned16 Coils: LARP: 1 station per coil, azimuthal (T) + TComp. and axial (Z) + TComp., 8 wires/coil, 32 wires/magnet CERN: 1 station per coil, 5 wires per T&Z, 10 wires/coil, 40 wires/magnet Shell: LARP: 1 shell with 4 stations, azimuthal (T) + TComp. and axial (Z) + TComp., 32 wires per magnet CERN: 1 shell with 4 stations, 5 wires per T&Z, 40 wires per magnet Rods: LARP only: 1 full-bridge gauge per rod, not temperature compensated, 4 wires per rod, 16 wires per magnet MQXFA (still in discussion) Most recent MQXFA1 proposal for (LARP + CERN) will triple: Three stations per coil (24/30 wires/coil, 96/120 wires/magnet) Three shells to be instrumented (96/120 wires per magnet) Rods will stay the same, 16/20 wires per magnet Installing only CERN-type SGs will reduce # of signals

Other Wiring Considerations for MQXFA1 Feb 2, 2016MQXFS Assembly Lessons Learned17 Cooling-hole jumper to bring the signals from the return end to lead end Contained in one of the four cooling holes that is expected to be compatible with MQXFA (along with BNL VMTF LHe fill tube) Fixed voltage tap (FVT) for quench detection Whole magnet ¼ magnet, ½ magnet, and ¾ magnet Wiring is connected at the splice box Wire: 30 AWG with Kapton/Tefzel insulation “Pigtails” were used to bring the signals from MQXFS1 to FNAL lambda plate FNAL provided the definition on connector type, layout and pinout Currently in discussion with BNL Power-lead wires for monitoring the Nb-Ti lead quench MQXFS had a pair of wires following the positive and negative lead from the NbTi/Nb 3 Sn splice to FNAL header Wire: 30 AWG with Kapton/Tefzel insulation Note: this connector packaging issue is only a “temporary” problem, as production magnets will not have as much instrumentation as the prototypes

MQXFS1 Wires and Routing Feb 2, 2016MQXFS Assembly Lessons Learned18 MQXFS1 PH had some labeling issues discovered recently – Documentation and information transfer has been addressed MQXFS Inner layer wiring was routed under the axial end plates via SLA (Accura Bluestone) wire guides – Guides performed as expected, and protected the wiring exiting the coil ends during axial loading operations

Lessons Learned Connectors and Instrumentation Feb 2, 2016MQXFS Assembly Lessons Learned19 Wiring and connector packaging density was at the limit of packaging for MQXFS1 Incorrectly labeled PH wiring in the LARP-style coils – This was a documentation and transfer issue, which has been addressed We are actively exploring MQXFA wiring and connectors issue – Color-coded PH wires may be re-introduced (if available in rad-hard wiring) – We may eliminate one set of strain gauges – Connectors may also be changed from Hypertronics

Summary Feb 2, 2016MQXFS Assembly Lessons Learned20 Magnet assembly processes yielded valuable experience to be applied to the MQXFA magnet with regards to reliability and efficiency – Ensuring safety in coil pack build operations – More reliable bladder operations on yoke-shell subassemblies – Improving efficiencies in magnet preassembly operations (GPI layers, radial collar shimming, coil pack assemblies, etc.) – Improving efficiencies in magnet integration operations (e.g. using “process keys” for stepped bladder operations) The MQXFA prototypes will need to deal with the large number of signals and connector packaging – We are actively working on these issues we experienced – However, this is a “temporary” problem that the production magnets will not suffer from

Feb 2, 2016MQXFS Assembly Lessons Learned21 Backup Slides

22 Instrumentation 22Feb 2, 2016 Three main instrumentations Voltage tap (VT) (including FVT) Protection heater (PH) Strain gauge (SG) Quench antenna not covered here For each type of instrumentation, we have four main components Connectors on the coil/component level Collectors/distributors at magnet lead and return ends Jumpers between lead and return ends Pigtail between lead end and test facility (lambda plate) We will review the case for MQXFS01 and provide projections for MQXFA01 MQXFS Assembly Lessons Learned

23 MQXFS01 voltage tap 23Feb 2, taps per coil, 8 taps per layer 64 taps in total In each layer, 6 taps from the lead end and 2 taps from the return end Wire: 30 AWG with Kapton/Tefzel insulation Same for MQXFA MQXFS Assembly Lessons Learned

24 MQXFS01 protection heaters 24Feb 2, heater strips per coil, 2 in inner layer and 4 in outer layer Same for MQXFA Maximum 6 heaters per coil MQXFS01: 4 heaters per coil (configured 2 heater circuits for outer layer, due to FNAL limitations) 16 heaters in total Wire: 16 AWG with Kapton/Tefzel insulation Heater configuration TBD for MQXFA Inner layer: 2 strips Outer layer: 4 strips MQXFS Assembly Lessons Learned

MQXFSD1 Collars and Load Pads Feb 2, 2016MQXFS Assembly Lessons Learned25 Load Pad Key feature – Load pad key feature on two pad assemblies (with slot features) 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

HQ02b Strain Gauges Feb 2, 2016MQXFS Assembly Lessons Learned26 LQ & HQ had some history of “losing” strain gauges upon cooldown – Adhesive could not be cured to manufacturer specified temperatures—we were not able to control adequately Somewhat inconclusive, though, because shell gauges still performed… – Tape securing thermal compensators was also causing these gauges to be lost Pre-Test Post-Test

HQ03a Strain Gauges: An Improvement Feb 2, 2016MQXFS Assembly Lessons Learned27 New procedures developed for HQ03a gauges: – SGs using new bonding procedures performed well; epoxy was able to cure at RT and remained intact when cold – SGs using old-style procedures in Coil 23 were lost on cooldown SGs using new procedures SGs using old-style procedures

MQXFSD1 Strain Gauges: A Promising Result Feb 2, 2016MQXFS Assembly Lessons Learned28 Used the new procedures, new gauges, and compensators – No gauges were lost during cooldown test – Full examination to follow after disassembly