270 likes | 280 Views
Subscale quadrupole (SQ) series. Paolo Ferracin LARP DoE Review FNAL June 12-14, 2006. Outline. Motivations and goals Magnet design SQ02 & SQ02b Overview Design features and axial load Test results Conclusions and next steps. Motivations and goals (SQ01). Test of support structure
E N D
Subscale quadrupole (SQ) series Paolo Ferracin LARP DoE Review FNAL June 12-14, 2006
Outline • Motivations and goals • Magnet design • SQ02 & SQ02b • Overview • Design features and axial load • Test results • Conclusions and next steps Paolo Ferracin
Motivations and goals (SQ01) • Test of support structure • Racetrack coil design (LBNL SM Program) • Assembly with keys and bladders • Aluminum shell • Realistic Lorentz forces • Early feed-back for TQS magnets • Assembly procedure • Component alignment • Stress uniformity • Goals achieved with SQ01 • Design and fabrication: Dec. 03 – July 04 • Successful test in Aug. 04 SQ TQS Paolo Ferracin
Motivations and goals (SQ02)Conductor test • Provide a means of evaluating conductor and cable under operating conditions similar to the TQ Paolo Ferracin
Motivations and goals (SQ02)Training studies • Validate numerical models related to magnet performance • Perform training and quench initiation studies • 3D FE model of the magnet geometry • Axial forces • Investigate dependence of magnet performance on axial loading Paolo Ferracin
Motivations and goals (SQ02)Technology development • New coil parts • Different assembly procedures • Quench propagation study • Cable characterization and comparison with modeling • Field quality measurements • Coil alignment with shell-type structure • Coil fabrication tolerances • Strain gauge R&D • Data analysis with different data acquisition systems Paolo Ferracin
Outline • Motivations and goals • Magnet design • SQ02 & SQ02b • Overview • Design features and axial load • Test results • Conclusions and next steps Paolo Ferracin
Magnet designSuperconducting coil • Cable • 0.7 mm strand • 20 strands, 7.9 X 1.3 mm • Insulation: 0.1 mm fiberglass • Racetrack coils • Double-layer • Iron / bronze island (pole) • 20 turns per layer • Horseshoe / end shoe containment structure • Aluminum bore • Clear aperture: 110 mm • Coil aperture: 130 mm Paolo Ferracin
Magnet design Support structure • Stainless steel pads • Iron yokes • Aluminum shell • Thickness: 22 mm • Outer diameter: 500 mm • 4 bladders and 8 keys for assembly and pre-load • Axial support • 4 aluminum rods • Diameter: 25 mm • Stainless steel end plate • Thickness: 50 mm • Pre-load applied with hydraulic cylinder • Strain gauges on shell and rods Paolo Ferracin
Outline • Motivations and goals • Magnet design • SQ02 & SQ02b • Overview • Design features and axial load • Test results • Conclusions and next steps Paolo Ferracin
Progress to date June – Aug. 05 Fabrication of 4 new coils Sept. 05 Assembly (“Initial axial load”) Oct. 05 Test at LBNL (SQ02) Dec. 05 Re-load (“Higher axial load”) Mar. 06 Test at FNAL (SQ02b) Next step End of FY06 Re-load (“Lower axial load”) Test (SQ02c) SQ02 overview Paolo Ferracin
SQ02 Design features • Test of TQ conductor and cable • Four new coils • SC17-SC16-SC18-SC19 • Training studies • Tests with different axial load • 3D FE models • Coils instrumentation • 1 spot heater • 4 strain gauges • 10 voltage taps • Technology development • New horseshoe design and bronze island • Improved assembly procedure (axial load first) Paolo Ferracin
Calculated short sample (extracted strand meas.) Iss (4.3 K) = 9.9 kA Bpeak (4.3 K) = 11.1 T Iss (4.5 K) = 9.8 kA Iss (1.8 K) = 10.8 kA Peak field in the end region ~ 2 T difference between ends and straight section SQ02Short sample limits Paolo Ferracin
Measured axial rod tension After assembly 70 MPa (150 kN) After cool-down 120 MPa (260 kN) Computed gap coil-island Friction model (µ = 0.2) Separation allowed 80 mm gap at short sample SQ02Axial load Paolo Ferracin
First thermal cycle 1st quench 5.9 kA (60 % Iss) 90 % in 13 quenches Highest quench 9.4 kA (95 % Iss) Second thermal cycle 1st quench 9.4 kA (95 % Iss) Highest quench 9.6 kA (97 % Iss) Bmax = 10.7 T Gmax = 81 T/m SQ02 test resultsConductor and magnet performance Paolo Ferracin
All quenches in the innermost turn Training quenches Trend from end segments to central segments Short sample quenches End segment (coil 18) SQ02 test resultsQuench locations • Training quench location Short sample quench location ▪Voltage tap Paolo Ferracin
Friction factor µ(0.2) Sliding distance [m] Contact frictional stress [N/m2] Frictional energy dissipation per unit area [J/m2] SQ02 FE model Frictional energy dissipation Fy Fz Paolo Ferracin
Frictional energy dissipation [J/m2]6000 A 7000 A Paolo Ferracin
Frictional energy dissipation [J/m2]7000 A 8000 A Paolo Ferracin
Frictional energy dissipation [J/m2]8000 A 9000 A Paolo Ferracin
Frictional energy dissipation [J/m2]9000 A 10000 A Paolo Ferracin
Measured axial rod tension After assembly 130 MPa (290 kN) Similar force as TQS01 After cool-down 190 MPa (410 kN) Computed gap coil-island Friction model (µ = 0.2) Separation allowed 40 mm gap at short sample 50 % reduction with respect to SQ02 SQ02bAxial load Paolo Ferracin
4.5 K 1st quench 9.1 kA (93 % Iss) Highest quench 9.5 kA (97 % Iss) Similar as second thermal cycle at LBNL 1.8 K 1st quench 9.8 kA (90 % Iss) Highest quench 10.6 kA (98 % Iss) SQ02b test resultsConductor and magnet performance Paolo Ferracin
Outline • Motivations and goals • Magnet design • SQ02 & SQ02b • Overview • Design features and axial load • Test results • Conclusions and next steps Paolo Ferracin
Conclusions • SQ series has been a successful R&D program • Cable and conductor evaluation • TQ01 conductor achieved 97-98 % of calculated Iss (both at 4.3 K and 1.8 K) without significant degradation due to stress • Training studies • Analysis of quench initiation and location through instrumentation consistent with numerical predictions • Study of the effect of axial load on magnet performance • Work in progress • Technology development • Improved assembly procedure (implemented in TQS) and new coil parts (same pole material as TQ) Paolo Ferracin
Retest with lower axial load (SQ02c) Comparison between SQ02b and SQ02c magnet performance Analysis of the effect of axial load on trained magnets Significant increase in computed end gaps Next steps (SQ02) Paolo Ferracin
Next steps (SQ03) • Cable and conductor evaluation • Fabrication of 4 new coils with RRP conductor (TQ02) • Training studies • Feed-back on mechanical analysis • Analysis of effect of axial load on magnet performance • Comparison with SQ02 (virgin magnet) • Technology development • New material for the island Paolo Ferracin