11 T Nb 3 Sn Demonstrator Dipole R&D Strategy and Status

1. 11 T Nb3Sn Demonstrator Dipole R&D Strategy and Status Zlobin, Fermilab 1st FNAL-CERN Collaboration Meeting Fermilab, May 13, 2011

2. Outline • 11 T Nb3Sn Dipole R&D Program • R&D phases, goals, design constraints • Comparison with other R&D programs • Single-aperture demonstrator R&D • Status • Schedule • Conclusions A. Zlobin - R&D Strategy

3. 11 T Nb3Sn Dipole R&D • In FY2011 Fermilab and CERN have started a joint R&D program with the goal of building a long twin-aperture Nb3Sn 11 T dipoleby 2014. • This R&D relies on the results of Nb3Sn magnet R&D programs at FNAL and Nb-Ti LHC magnet development at CERN. • To meet the tight project schedule within the available budget, magnets are designed to make maximum use of the existing tooling, infrastructure, and magnet components at both laboratories. • Practical orientation is a key feature for any sound Nb3Sn accelerator magnet R&D program at the present time. A. Zlobin - R&D Strategy

4. Result Application • LHC collimation system upgrade. • 11 T 11-m long twin-aperture Nb3Sn dipoles compatible with the LHC lattice and major systems can provide the required space for cold collimators • additional design constrains • Space in the LHC lattice for different insertion devices • dynamic collimators, correctors, instrumentation, etc. A. Zlobin - R&D Strategy

5. R&D Phases and Goals Productive CERN-FNAL collaboration is a key to success! A. Zlobin - R&D Strategy

6. Constraints • 11+ T at the LHC nominal current and operation temperature, 20% margin, field quality, quench protection • Compatibility with MB cold mass and cryostat designs • aperture diameter and separation, cold mass OD, heat exchanger • Nominal field >11 T => Nb3Sn • 20% operational margin at 1.9 K => Bmax=13.2 T • Common yoke and separate collared coils • collaring press capability limit at FNAL, lower risk • Magnet length ~11 m, coil length ~5.5 m • Tooling limitations at FNAL, shorter strand and cable length, lower scale up risk FNAL FNAL CERN CERN 11m Magnet 5.5 m Dipole Cold Mass A. Zlobin - R&D Strategy

7. Single-bore Demonstrator • Challenges: aperture, length, Bmax, W, schedule A. Zlobin - R&D Strategy

8. Twin-bore Demonstrator • Challenges: 2-in-1 horizontal configuration, aperture, aperture separation, Bmax, length, schedule A. Zlobin - R&D Strategy

9. Scale Up Challenges LARP: • 4-m long single-aperture quadrupole by 2014 • Test in vertical dewar at VMTF (Fermilab) at 1.9-4.5 K 11 T Dipole program: • 5.5-m long single coil test in MQXB prototype cryostatin 2013 (Fermilab or CERN) • 5.5-m long twin-aperture dipole by 2014 • Assembly with LHC MB cryostat and test at CERN MTF at 1.9-4.5 K A. Zlobin - R&D Strategy

10. 11 T R&D Impact • Very interesting and challenging R&D program • Benefit generic SC accelerator magnet R&D • Nb3Sn practical application in HL-LHC • Step towards high-field magnets for HE-LHC A. Zlobin - R&D Strategy

11. Demonstrator R&D • R&D status • Strand and cable • Magnetic design and parameters • Mechanical design and analysis • Quench protection • Magnet design and infrastructure • Details in the following talks A. Zlobin - R&D Strategy

12. Table 1: Cable parameters Strand and Cable • Strand (OST): • 0.7 mm Nb3SnRRP-108/127 • high-Jc, relatively stable • Cable (FNAL): • 15-mm wide, 40 strands • Cable insulation: • 0.075-mm E-glass tape • 2 layers butt lap • traditional insulation technique • Strand procurement • 60 kg RRP-151/169 – R&D (Aug 2011) • 152 kg RRP-108/127 (Dec 2011) • 152 kg RRP-108/127 (Jul 2012) • Cable fabrication • Practice cable fabricated and tested • Cable for demonstrator in progress • Details by Daniele. A. Zlobin - R&D Strategy

13. Coil Design • Design • 2-layer 6-block design • 60-mm aperture • Coil winding, curing, reaction and impregnation tooling designed and procured • Coil components designed and procured • Coil end parts were designed and fabricated by CERN • Coil fabrication • 1st practice coil wound and cured • Rectangular copper cable • 2nd practice coil winding started • RRP-114/127 keystone cable • Details by Mikko and Fred. A. Zlobin - R&D Strategy

14. Dipole Parameters A. Zlobin - R&D Strategy

15. Mechanical Structure • Design • 25-mm thick slightly elliptical stainless steel collar • Vertically split iron yoke • Al clamps • 12.7-mm stainless steel skin • 50-mm thick end plates • Structure design and mechanical analysis complete • Maximum stress in coil <160 MPa • stresses in structure are within limits • Collar design complete and procurement started. • Assembly tooling design is in progress. • Details by Igor and Fred. A. Zlobin - R&D Strategy

16. Quench Protection • Demonstrator quench protection during test will be provided by extracting the stored magnetic energy on the appropriate external dump resistor. • In accelerator, the magnet protection is provided by quench heaters. • Quench protection heaters composed of stainless steel strips will be placed inside the ground insulation, covering the outer-layer coil blocks. • Quench protection analysis and heater design are in progress (Mikko). A. Zlobin - R&D Strategy

17. Schedule, Milestones, QA Demonstrator specs DOE review Cable review Winding review Coil review Structure review Performance review A. Zlobin - R&D Strategy

18. Conclusions • 11 T Nb3Sn demonstrator dipole magnets for possible use in accelerators in particular for the LHC upgrades are being developed by Fermilab/CERN collaboration. • The engineering design of the 60-mm single-aperture 2-m long magnet and fabrication tooling is nearly complete and practice coil winding is in progress. • The cold tests are planned towards the end of 2011 • Primary goal: demonstrate the quench performance, nominal field, and operation margins • Auxiliary studies: field quality, magnet quench protection • The conceptual design of the twin-aperture 11 T dipole magnet has been started. A. Zlobin - R&D Strategy