1. Subscale quadrupole (SQ) series Paolo Ferracin LARP DoE Review FNAL June 12-14, 2006

2. Paolo Ferracin 06/13/2006 Outline Motivations and goals Magnet design SQ02 & SQ02b Overview Design features and axial load Test results Conclusions and next steps

3. Paolo Ferracin 06/13/2006 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

4. Paolo Ferracin 06/13/2006 Motivations and goals (SQ02) Conductor test Provide a means of evaluating conductor and cable under operating conditions similar to the TQ I strand B peak Stresses TQ~ 460 A11.3 T100-150 MPa SQ~ 490 A11.1 T100-150 MPa

5. Paolo Ferracin 06/13/2006 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 F z total A coil zz TQ350 kN4300 mm 2 81 MPa SQ340 kN3900 mm 2 87 MPa

6. Paolo Ferracin 06/13/2006 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

7. Paolo Ferracin 06/13/2006 Outline Motivations and goals Magnet design SQ02 & SQ02b Overview Design features and axial load Test results Conclusions and next steps

8. Paolo Ferracin 06/13/2006 Magnet design Superconducting 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

9. Paolo Ferracin 06/13/2006 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

10. Paolo Ferracin 06/13/2006 Outline Motivations and goals Magnet design SQ02 & SQ02b Overview Design features and axial load Test results Conclusions and next steps

11. Paolo Ferracin 06/13/2006 SQ02 overview 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)

12. Paolo Ferracin 06/13/2006 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)

13. Paolo Ferracin 06/13/2006 SQ02 Short sample limits Calculated short sample (extracted strand meas.) I ss (4.3 K) = 9.9 kA B peak (4.3 K) = 11.1 T I ss (4.5 K) = 9.8 kA I ss (1.8 K) = 10.8 kA Peak field in the end region ~ 2 T difference between ends and straight section

14. Paolo Ferracin 06/13/2006 SQ02 Axial load 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  m gap at short sample

15. Paolo Ferracin 06/13/2006 SQ02 test results Conductor and magnet performance First thermal cycle 1 st quench 5.9 kA (60 % I ss ) 90 % in 13 quenches Highest quench 9.4 kA (95 % I ss ) Second thermal cycle 1 st quench 9.4 kA (95 % I ss ) Highest quench 9.6 kA (97 % I ss ) B max = 10.7 T G max = 81 T/m

16. Paolo Ferracin 06/13/2006 SQ02 test results Quench locations All quenches in the innermost turn Training quenches Trend from end segments to central segments Short sample quenches End segment (coil 18)  Training quench location  Short sample quench location ▪ Voltage tap

17. Paolo Ferracin 06/13/2006 SQ02 FE model Frictional energy dissipation Friction factor  µ (0.2) Sliding distance   [m] Contact frictional stress   [N/m 2 ] Frictional energy dissipation per unit area    [J/m 2 ] FzFz FyFy

18. Paolo Ferracin 06/13/2006 Frictional energy dissipation [J/m 2 ] 6000 A  7000 A

19. Paolo Ferracin 06/13/2006 Frictional energy dissipation [J/m 2 ] 7000 A  8000 A

20. Paolo Ferracin 06/13/2006 Frictional energy dissipation [J/m 2 ] 8000 A  9000 A

21. Paolo Ferracin 06/13/2006 Frictional energy dissipation [J/m 2 ] 9000 A  10000 A

22. Paolo Ferracin 06/13/2006 SQ02b Axial load 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  m gap at short sample 50 % reduction with respect to SQ02

23. Paolo Ferracin 06/13/2006 SQ02b test results Conductor and magnet performance 4.5 K 1 st quench 9.1 kA (93 % I ss ) Highest quench 9.5 kA (97 % I ss ) Similar as second thermal cycle at LBNL 1.8 K 1 st quench 9.8 kA (90 % I ss ) Highest quench 10.6 kA (98 % I ss )

24. Paolo Ferracin 06/13/2006 Outline Motivations and goals Magnet design SQ02 & SQ02b Overview Design features and axial load Test results Conclusions and next steps

25. Paolo Ferracin 06/13/2006 Conclusions SQ series has been a successful R&D program Cable and conductor evaluation TQ01 conductor achieved 97-98 % of calculated I ss (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)

26. Paolo Ferracin 06/13/2006 Next steps (SQ02) 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

27. Paolo Ferracin 06/13/2006 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