MQXFPM1 and MQXFS1b Test Results GianLuca Sabbi HL LHC Collaboration Meeting 2016

Mirror Test Objectives and Features Magnetic mirror structure allows standalone testing of coils Developed by FNAL GARD and used extensively by LARP Provides early feedback on cable and coil design/fabrication Main driver is single coil requirement, not faster assembly/test Useful at the start of a new series, or to check design/processing variants Strength: demonstrated capability to achieve conductor limit Weakness: generally slow training (but: faster quench recovery due to lower stored energy) Note: some results not representative of quadrupole layout (e.g. ramp rate dependence) A key step in the development of both short and long coils R. Bossert G. Sabbi – MQXFPM1and MQXFS1b Test Results 11/15/2016

MQXFPM1 Conductor Parameters and SSL Short Sample Limit at 1.9K Parameter Unit MQXFSM1 MQXFPM1 Alloy (Nb-7.5w%Ta)3Sn (Nb-1.5a%Ti)3Sn Sub-element layout 108/127 Non-Cu fraction % 43.6 45.5 Cable Width mm 18.094 18.156 Cable Mid-Thickness 1.529 1.525 Keystone angle Deg. 0.52 0.56 Magnet Current Field Unit kA T MQXFPM1 22.09 15.05 MQXFSM1 21.07 14.5 MQXFS1 21.50 14.6 XS RRR Average 295 Maximum 341 Minimum 206 MQXFPM1 HT Temp [C] Time [h] 210 74 401 49 641 48 A. Ghosh, I. Pong G. Sabbi – MQXFPM1and MQXFS1b Test Results 11/15/2016

MQXFPM1 Assembly Steps and Pre-Load Welded s.s. skin SM1 Bolted s.s. skin Mirror magnet azimuthal pre-load (MPa) Assembly Step Design Actual Short Mirror Actual Long Mirror In press, before Al clamp insertion 80 79 74 Side clamp inserted, press released 50 66 After shell welding (bolting) 70 77 98 R. Bossert, I. Novitski G. Sabbi – MQXFPM1and MQXFS1b Test Results 11/15/2016

MQXFPM1 Fabrication and End Load Coil in lower yoke End Plates welded, and installing End Preload Bolts End pre-load in mirror is much lower than in quadrupole short model R. Bossert, I. Novitski G. Sabbi – MQXFPM1and MQXFS1b Test Results 11/15/2016

MQXFSM1 and MQXFPM1 Quench Training Long Mirror PM1 A3-A4 and A4-A5 Short Mirror SM1 G. Chlachidze, S. Stoynev, J. Muratore G. Sabbi – MQXFPM1and MQXFS1b Test Results 11/15/2016

MQXFPM1 Protection, Status and Next Steps Test Plan Assumptions: 33 mW dump resistor <15 ms detection time <21 MIITs during training <30 MIITs for quench studies Initial quenches: 16.5 mW dump for lower voltage 22 ms detection time (16 kA) Measured quench load: 30.8 MIITs Status and next steps: Performed data analysis and comparison with models Replaced one IGBT that was damaged in the second training quench Increased dump resistor back to 33 mW Performed hi-pot ok up to 800 V (80K); system checks at 4.5K in progress Planning to decrease 10 ms validation time and (possibly) detection threshold E. Ravaioli, J. Muratore G. Sabbi – MQXFPM1and MQXFS1b Test Results 11/15/2016

Reference: MQXFS1 Design Report, MQXFS1 Quadrupole First-generation cable and coil design (larger keystone angle) Two coils from CERN and two from LARP CERN (#103 and #104) – RRP 132/169 LARP (#3 and #5) – RRP 108/127 Magnetic length 1.2 m, Coil length 1.5m Reference: MQXFS1 Design Report, http://larpdocs.fnal.gov//LARP-public/DocDB/ShowDocument?docid=1074 MQXFS1 Coils: Outer Layer MQXFS1 Coils: Inner Layer CERN 103 & 104 CERN 103 & 104 LARP 3 & 5 LARP 3 & 5 D. Cheng, J. Schmalzle, J.C. Perez, M. Yu et al. G. Sabbi – MQXFPM1and MQXFS1b Test Results 11/15/2016

Short Sample and Reference Current Levels Parameter Current Field Gradient Inom/Iss Temperature 1.9 K Unit kA T T/m % Coil 103 21.50 14.6 169.08 77 Coil 104 21.78 14.77 171.03 76 Coil 3 22.28 15.08 174.57 74 Coil 5 21.85 14.81 171.52 75 Current [kA] Symbol Gradient [T/m] Remarks 0.01 I.warm 0.09 Warm measurements 0.1 I.res 0.9 Reset level for pre-cycle 0.96 I.inj 8.5 Injection level 6.0 I.lim 48.8 Current limit (pre-training) 16.48 I.nom 132.6 Nominal level 17.76 I.ult 143.2 Ultimate level 21.50 I.ssl 171.0 1.9K Short Sample Limit Parameter Current Field Gradient Unit kA T T/m Coil 103 19.55 13.38 155.16 4.3K SSL: B. Bordini, A. Ghosh, P. Ferracin G. Sabbi – MQXFPM1and MQXFS1b Test Results 11/15/2016

MQXFS1 Quench Analysis Quench locations: Quenches observed in all coils and distributed over many locations in the high field areas About 50% in coil 103 (both lower margin and earlier unloading) Some quenches in end regions and layer ramp Strain gauges: Preload increase during cool- down lower than expected During excitation, deviation from linear behavior starts at about 65% of SSL H. Pan, T. Strauss, G. Vallone G. Chlachidze, S. Stoynev Strain gauges, distribution of quench locations, and quench level independent of temperature consistently indicate low pre-load as the main limiting factor No indication of coil performance degradation up to the quench level achieved G. Sabbi – MQXFPM1and MQXFS1b Test Results 11/15/2016

HQ02 Training Rate vs. Pre-load HQ02a/a2 slow training above 80% SSL, attributed to low pre-load HQ02b: Much faster training up to 95% SSL after pre-load increase H. Bajas, M. Bajko, G. Chlachidze, M. Martchevsky, F.Borgnolutti, D. Cheng, H. Felice, et al. G. Sabbi – MQXFPM1and MQXFS1b Test Results 11/15/2016

From MQXFS1 to MQXFS1b Average azimuthal pre-load increased from 80 to 100 MPa No change in axial pre-load: 600 kN, half of Lorentz force D. Cheng, H. Pan, G. Vallone G. Sabbi – MQXFPM1and MQXFS1b Test Results 11/15/2016

MQXFS1b vs MQXFS1 Quench Training MQXFS1b fully retained the maximum quench level achieved in MQXFS1 Quench level further improved, but with slower rate and some fall backs Highest quench so far: 18.8kA, 87.4% SSL @1.9K Next steps: protection studies and further localization of quench origin G. Chlachidze, S. Stoynev G. Sabbi – MQXFPM1and MQXFS1b Test Results 11/15/2016

MQXFS1b Quench Instrumentation Voltage Taps Axial field quench antenna Antenna is installed in warm bore – can be moved and reconfigured M. Martchevsky G. Sabbi – MQXFPM1and MQXFS1b Test Results 11/15/2016

MQXFS1b Quench Locations Most quenches developed in the end regions: Voltage taps: IL Pole block A3-A4 segment QA: LE, segment #1 (11 quenches) and RE, segment #7 (4) Segment #8 not connected due to limited DAQ channels 1 seg - Coil #3, quench in A3-A4 2 seg – Coil #3, quench in A3-A4 and A4-A5 Additional training quenches are planned in addition to protection studies Quench antenna is being reconfigured for more precise quench localization G. Chlachidze, S. Stoynev, M. Martchevsky, T. Strauss G. Sabbi – MQXFPM1and MQXFS1b Test Results 11/15/2016

QA reconfiguration LE quench localization QA coils are now closely spaced around the LE quench area Accurate localization of QA relative to magnet coil is also required Possibility to cross-correlate with voltage taps or MM probe Increased delays are being considered (sufficient QI margin) Installation on warm bore provides much increased flexibility Probe can also be rotated to provide left-right positioning T. Strauss, M. Martchevsky G. Sabbi – MQXFPM1and MQXFS1b Test Results 11/15/2016

Comparison between HQ02 and MQXFS1 Ends MQXF coil-spacer interface has tension not observed in HQ02 Tension appears to increase with higher pre-load (needs to be confirmed/quantified) Also high compression, but different areas for MQXF vs. HQ One additional block in MQXF than in HQ Flexible spacers also implemented in MQXF HQ02a (L1) HQ02b (L1) MQXFS1a (L1) MQXFS1b (L1) H. Pan, G. Vallone G. Sabbi – MQXFPM1and MQXFS1b Test Results 11/15/2016

Magnetic Measurements and Protection Studies Effect of magnetic shim Magnetic Measurements: [S. Izquierdo Bermudez presentation] Reduced plan in MQXFS1b relative to MQXFS1 Focus on harmonics correction with magnetic shim Two harmonics were targeted: effect is consistent with calculation, but in one case sign is opposite Need to ensure correct referencing of magnetic measurements, calculations and shim installation J. DiMarco Protection studies: [E. Ravaioli presentation] Extensive protection studies are planned in both MQXFS1b and MQXFPM1 MQXF1b: first opportunity to test CLIQ on the MQXF design Mirror: first opportunity to verify heater performance and modelling predictions on a long MQXF coil Long Mirror Quench #1 Analysis G. Sabbi – MQXFPM1and MQXFS1b Test Results 11/15/2016

Summary Long Mirror MQXFPM1: MQXFS1b Quadrupole: First feedback on MQXF Long Coil Performance Start of training is comparable to short mirror New test facility commissioned at BNL Need to proceed with caution to ensure safe operation during training MQXFS1b Quadrupole: Training started at the maximum quench level achieved in MQXFS1 Quench level further improved, but with slower rate and some fall backs Quenches are primarily in the ends, different from HQ/LARP experience Need to determine cause for end quenches, and corrective actions Diagnostic effort centered on axial field antenna to precisely locate quenches Highest quench so far: 18.8kA, 87.4% SSL @1.9K Magnetic shim correction: wo harmonics were targeted, effect is consistent with calculation, but in one case sign is opposite Extensive protection studies underway: first opportunity to test CLIQ in MQXF G. Sabbi – MQXFPM1and MQXFS1b Test Results 11/15/2016

Backup Slides G. Sabbi – MQXFPM1and MQXFS1b Test Results 11/15/2016

Previous QA Configurations G. Sabbi – MQXFPM1and MQXFS1b Test Results 11/15/2016

D20 Training History G. Sabbi – MQXFPM1and MQXFS1b Test Results 11/15/2016