MQXFA Magnets Status Update Giorgio Ambrosio Magnets L
MQXFA Magnets Status Update Giorgio Ambrosio Magnets L 2 PMG mtg, September 17 th, 2019
Outline § Recent International Reviews § MQXFA Fabrication Status § Issues, Concerns and Plans to Address Them G. Ambrosio - MQXFA Magnets Status Update 2
Production Readiness Reviews • Gradient requirement: • R 2. 4. 2: We recommend that no magnets be rejected if they achieve nominal field + margin (% TBD), but not ultimate field. • F 3. 4: After the conclusion of the review, the committee was informed that CERN and HL-LHC management have determined that the 11 T dipole project should not attempt to achieve the ultimate current performance as part of the test criteria. • R 3. 8: 8. Re-evaluate the acceptance criteria of the MQXF magnets to maintain consistency across the HL-LHC magnet production efforts. G. Ambrosio - MQXFA Magnets Status Update 3
Production Readiness Reviews • Quench Protection Heaters: G. Ambrosio - MQXFA Magnets Status Update 4
Production Readiness Reviews • Other topics: • R 3. 1: Review each detailed component design from a total systems standpoint. • R 3. 2: Consider mixing superconductor strand to minimize the standard deviation in performance of the Rutherford cables. G. Ambrosio - MQXFA Magnets Status Update 5
• New Inner Triplet Circuit: • Not yet approved by HL-LHC • Supported by reviewers G. Ambrosio - MQXFA Magnets Status Update 6
• Quench Protection Heaters: • Two important messages “received” by CERN/HL-LHC: • MQXF Heater-Coil voltages = 0. 5 x 11 T Heater-Coil voltages • MQXFA Heater-Coil voltages = 0. 6 x MQXFB Heater-Coil voltages G. Ambrosio - MQXFA Magnets Status Update 7
• Proposed new test in Electrical Design Criteria: • For MQXF magnets (Heater-Coil): • Hipot at 850 V in He gas (~1 bar) at ~100 K after magnet training • 11 T is NOT going to do it, because it may fail at 1680 V • Review committee did NOT support it • Other CERN experts did support it G. Ambrosio - MQXFA Magnets Status Update 8
New Test & Present Design • Does the present design meet the proposed test/requirement? • Answer: yes (with limited statistic) Fig 5. Heater-Coil Hi. Pot in He gas (1 bar) after magnet training Proposed test MQXFAP 1 b prototype 9
Outline • Recent International Reviews • MQXFA Fabrication Status • Issues, Concerns and Plans to Address Them G. Ambrosio - MQXFA Magnets Status Update 10
302. 2. 02: Conductor Procurement & QC • Strand Procurement and QC: • • Last but one procurement was placed Conductor is being delivered timely No significant issues BOST run out of He for QC tests (cap be vendor); Fermilab is providing He gas and getting credit back G. Ambrosio - MQXFA Magnets Status Update 11
302. 2. 03: Cable Fabrication Status • Bare cable fabrication at LBNL: • Finished 035 • Insulation braiding at NEWT: • Finished 032 • RRR measurements • Measured up to 029 • Completed cables: • 27 Accepted • 1 Rejected • Crossover caused by Cu build-up on spool at vendor HL-LHC AUP FNAL PMG - 2019 09 17 12
302. 2. 04: Coil Parts Status In Stock (set) Coils in stock Covered from FY 19 Procurement (set) FY 20 Procurement (set) Pole 11 QXFA 120 QXFA 212 26 (Received 50%, and 25% inspected) 40 End Parts 11 26 (Received 50% and all inspected) 40 Wedges 23 72 (PO placed, expected to receive by Dec. 2019) 0 Pre-series Trace 3 QXFA 117 QXFA 209 6 (expected to receive by Oct. 2019) 0 Series Trace 26 - 0 26 § FY 20, AUP plans to fabricate 20 coils. § Pole and end parts in stock, plus 26 sets of pole and end parts that are expected to arrive by Dec. 2019, will cover all the need in FY 20. § Wedges and traces in stock, plus October delivery, will cover all the need in FY 20.
302. 2. 05: Coils at FNAL LARP coils Notes: Saddles changed after curing No more saddle change Impregnation process Winding strand damage Hold during A 115 bump investigation G. Ambrosio - MQXFA Magnets Status Update 14
302. 2. 06: Coils at BNL • Coils to date = 8 (4 complete, 2 rejected, 2 underway): • QXFA 202 - Complete and shipped (1 st coil completely fabricated at BNL). • QXFA 203 - Complete and shipped. • QXFA 204 - Complete and shipped. • QXFA 205 - Cable damaged during winding – coil rejected. • QXFA 206 - Complete and ready to be shipped. • QXFA 207 - Reaction complete, impregnation underway. • QXFA 208 - Cable damaged during curing – coil rejected. • QXFA 209 - Winding underway. September 13, 2019 15
302. 2. 07: Structures Status at LBNL • MQXFA 03 Magnet (first Pre-Series) • • Magnet is assembled Magnetic measurements have been taken, being processed Final Electrical QC being performed QA/MIP documentation to be compiled and uploaded for review and approval • Magnet should arrive at BNL at the end of September MQXFA Structures Status at LBNL - 17 -Sep-2019 16
302. 07: Structures Status at LBNL • MQXFAP 2 arrived at LBNL • New “disassembly shell” has been fabricated • Used blank 7075 -T 652 forging • Epoxy-filled shims (developed under MDP CCT program) to be used to fill gaps to allow bladders to function properly • MQXFAP 2 to be disassembled after MQXFA 03 magnet ships • Recovery of parts • Approx. $400 k of “recovered” parts can used for MQXFA 04 assembly • Also alleviates schedule delay due to ARMCO shipment MQXFA Structures Status at LBNL - 17 -Sep-2019 17
302. 07: Structures, Looking Ahead • MQXFA 04 magnet expected to be ready to ship at the end of January 2020 • Will use conforming parts recovered from MQXFAP 2 • Parts for structures A 04 -A 08 are arriving over the next few months • ARMCO steel to start arriving at destinations in early October MQXFA Structures Status at LBNL - 17 -Sep-2019 18
Outline • Recent International Reviews • MQXFA Fabrication Status • Issues, Concerns and Plans to Address Them G. Ambrosio - MQXFA Magnets Status Update 19
Gradient in FRS and Acceptance Criteria • Consensus to limit MQXFA tests to Nominal Current plus limited margin (100 -200 A) • Strong resistance by CERN to change FRS and Acceptance Criteria • AUP Plan is to demonstrate Nominal Current in MQXFA magnets, and then request change of requirements before testing Cryo-assemblies G. Ambrosio - MQXFA Magnets Status Update 20
Quench Heaters AUP plan: • Accept new Hipot in He gas after magnet training • Demonstrate that MQXFA magnets pass this test • Reduce risk of negative impact on magnet yield by developing low-risk alternative process for Heater installation • Next slide G. Ambrosio - MQXFA Magnets Status Update 21
Quench Heater Alternative Process • Demonstrating alternative process to install Quench Heaters: • Swap heater trace with one layer of fiberglass (at present 2 layers on top of heater trace) • Completed coil S 04 with alternative process • Electrical tests and inspection Good • Fabricating 1 short coil with alternative process • Test it in short mirror (Jan 2020) • After test: Hipot at 850 V in He gas at 100 K G. Ambrosio - MQXFA Magnets Status Update 22
Quench Heaters Next Steps • Technical mtg with CERN to discuss technical assessment, and flow chart with magnet tests and decision points • Managerial mtg with CERN to discuss impact of any design change • Presentation at HL-LHC Collab mtg of impact of any design change G. Ambrosio - MQXFA Magnets Status Update 23
Coil Yield • Coil fabrication is still through learning curve • Corrective & Preventive Actions are being implemented: no issue is repeated • Soon we should be going out of the learning curve, although more techs will be needed in order to increase production rate • Going to use Estimate At Completion as tool to monitor progress vs baseline G. Ambrosio - MQXFA Magnets Status Update 24
Backup Slides G. Ambrosio - MQXFA Magnets Status Update 25
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