1. LARP Collaboration Meeting, April 26-28, 2006Gian Luca Sabbi HQ Design Study (WBS 2.1.4.1) LARP Collaboration Meeting April 26-28, 2006 N. Andreev, E. Barzi, S. Caspi, D. Dietderich, P. Ferracin, A. Ghosh, V. Kashikhin, I. Novitski, GianLuca Sabbi, A. Zlobin BNL - FNAL - LBNL - SLAC

2. LARP Collaboration Meeting, April 26-28, 2006Gian Luca Sabbi 2 HQ Design Study Goals & Milestones 1. Develop HQ design and R&D plan in preparation for model fabrication: - Magnetic, mechanical and quench analysis - R&D issues, magnet parameters and features 2. Provide input to LHC IR quad conceptual design and analysis: - Optics, IR layout, radiation deposition, cryogenics studies FY06: Focus on coil FY07: Focus on structure

3. LARP Collaboration Meeting, April 26-28, 2006Gian Luca Sabbi 3 HQ Design Issues Conductor: - strand (optimal design, critical current at high field) - cable (limits on maximum width & keystone angle) Magnetic: - number of layers (cable design, winding issues) - use of wedges, conductor grading, end field optimization - Lorentz stresses Mechanical: - collar-based vs. shell-based structure - structure and coil alignment - end axial support Integration:- coordination with model magnet, supporting R&D - coordination with IR magnets study - fabrication, cost and schedule considerations - target parameters, design features, R&D plan

4. LARP Collaboration Meeting, April 26-28, 2006Gian Luca Sabbi 4 Cross-section analysis and selection Same current density. How to account for cabling/stress degradation Strand parameters (diameter, cu/sc): consistent (same) and practical Cable parameters (no. str., angle, compact.): consistent (same) & approved Iron yoke: same distance from coil and magnetic properties Pre-conditions for comparison: Criteria for comparison: Maximum gradient Coil stress distributions Practicality, cost and schedule: strand procurement, use of TQ tooling (coils) Winding/Fabrication issues: minimum radii, spacer design, radial placement Complications vs. R&D interest/features Coil volume, Quench protection, Field quality,...

5. LARP Collaboration Meeting, April 26-28, 2006Gian Luca Sabbi 5 Critical current assumptions

6. LARP Collaboration Meeting, April 26-28, 2006Gian Luca Sabbi 6 Reference strand parameters B, T T=4.2KT=1.9K J c (B,T), A/mm 2 dJ c (B,T)/dB, A/mm 2 /T J c (B,T), A/mm 2 dJ c (B,T)/dB, A/mm 2 /T 12.03000 -591 3827 -663 12.52716 -547 3507 -617 13.02452 -507 3209 -575 13.52208 -470 2931 -536 14.01982 -435 2672 -500 14.51772 -403 2431 -466 15.01579 -372 2206 -435 15.51996 -405 16.01800 -377 16.51618 -351 17.01449 -326 Assumed Cu/Sc ratio: 0.87 (based on RRP 54/61)

7. LARP Collaboration Meeting, April 26-28, 2006Gian Luca Sabbi 7 Cable parameters

8. LARP Collaboration Meeting, April 26-28, 2006Gian Luca Sabbi 8 Number of Layers Compared 2, 3, and 4-layer coil designs from the design and fabrication standpoint 2-layer design: smallest number of parts and fabrication steps (+) requires a cable with large aspect ratio (-) difficulties in design of the end parts and in coil winding (-) 3-layer design: reduce the cable width (+) maintain a continuous winding in each quadrant, minimize joints (+) constraints to the coil design: more axial space for the coil ends (-) 4-layer design: twice as many coils, tooling and fabrication steps as to 2-layer design (-) can reach 40 mm coil width while limiting the cable width (+) allows grading of the outer two layers at small extra cost (+) Allows re-use of some TQ tooling (and perhaps coils) (+)

9. LARP Collaboration Meeting, April 26-28, 2006Gian Luca Sabbi 9 Yoke Parameters Coil-yoke distance varies – OD 280 Yoke OR varies Assumptions for preliminary magnetic optimization: Yoke OD 250 mm Coil-yoke distance 10 mm Non linear B-H curve

10. LARP Collaboration Meeting, April 26-28, 2006Gian Luca Sabbi 10 Selected 4-layer cross-sections Note: gradients are in quotes because they are not all computed in a consistent manner Vadim #7 “317 T/m” Vadim #6 “309 T/m” Paolo graded “313 T/m” Paolo “TQ” “307 T/m” GRADEDNON GRADED

11. LARP Collaboration Meeting, April 26-28, 2006Gian Luca Sabbi 11 Coil Stress Analysis Cross-section designs considered: “TQ” inner layer, not graded Paolo graded Vadim graded (# 7) Magnetic assumptions: Real iron Rin iron = Rout coil + 5 mm Rout iron = 280 mm Gradient = 300 T/m Mechanical Assumptions: Layer 1-2 and Layer 3-4 bonded Layer 2-3 sliding

12. LARP Collaboration Meeting, April 26-28, 2006Gian Luca Sabbi 12 “TQ” Inner Layer, not graded 108126173152

13. LARP Collaboration Meeting, April 26-28, 2006Gian Luca Sabbi 13 “TQ” Inner Layer, not graded 108126173152

14. LARP Collaboration Meeting, April 26-28, 2006Gian Luca Sabbi 14 Paolo Graded 119172124118

15. LARP Collaboration Meeting, April 26-28, 2006Gian Luca Sabbi 15 Paolo Graded 119172124118

16. LARP Collaboration Meeting, April 26-28, 2006Gian Luca Sabbi 16 Vadim graded (#7) 135128135107

17. LARP Collaboration Meeting, April 26-28, 2006Gian Luca Sabbi 17 Vadim graded (#7) 135128135107

18. LARP Collaboration Meeting, April 26-28, 2006Gian Luca Sabbi 18 Reference cross-sections “TQ” inner layerGraded 307 T/m 317 T/m

19. LARP Collaboration Meeting, April 26-28, 2006Gian Luca Sabbi 19 Summary Two reference cross-sections were selected Next steps: Magnetic: Refine cable parameters (feedback from materials R&D) Preliminary design of coil ends; peak field issues Complete magnetic cross section (2 options) Mechanical More detailed comparison of preload requirements Design of structure Comparison with larger aperture designs Magnetic, mechanical, quench Cost and schedule