The Future High Field NMR Magnet Program at the NHMFL: Possibilities

1. The Future High Field NMR Magnet Program at the NHMFL: Possibilities W. Denis Markiewicz Users Committee Meeting November 12-13, 2004

2. NHMFL Very High Field NMR Program Structure 25 T 1066 MHz 900 MHz 21.1 T Technology Development Conductor Reinforcement Protection Coil Form Refrigerator Spectrometer Conductor Magnet 750 MHz 600 MHz

3. Candidate High Field Superconducting Magnets VHF NMR Field 25 T – 28 T Warm bore 52 mm High resolution Persistent 25 T standard uniformity Uniformity 1x10-3 – 1x10-4 Cold bore 52 mm Powered Rampable

4. HTS Conductor Preference and Availability Conductor preference high field properties long lengths, precision layer winding persistent joint technology Conductor availability good high field electrical properties usable mechanical properties powered mode technology

5. HTS Conductor Preference and Availability Conductor preference high field properties long lengths, precision layer winding persistent joint technology very far off Conductor availability good high field electrical properties usable mechanical properties powered mode technology presently available

6. Alternative Programs available HTS conductor related HTS coil technology 25 T 1.1 GHz 25 T and 1.1 GHz

7. 25T Research Solenoid(not funded) • Special requirements • Very high field (too high for LTS alone) • Moderate cycling, 0 to high field • Approach • LTS/HTS technology • Improved, high-strength Nb3Sn • HTS tape conductors • Bi-2212 • Bi-2223 • General improvements to intra-coil materials and components • 4.2K bath cooling • Involve commercial sector to the greatest practical extent • Technology needs • Improved and expanded database for materials and components • Careful modeling and test of critical components • No inventions foreseen • Cost and schedule • 8-10 M$ for LTS section • ? for HTS section • 6 years to turn on (tech-limited schedule) 25T RS 900 MHz

8. High Field NMR Magnet Specification with available HTS conductor Field 1.1 GHz (26 T) Warm bore 54 – 64 mm Uniformity 1 ppb in 1 cm DSV Operating temperature a) 4.2 K b) 1.8 K -2.2 K Δ B HTS a) 8 T b) 6 T Operating mode powered

9. First Generation Wire Maturity Leads to Product Differentiation HTS Applications Now Require Specialized Wires High Current Density High Strength Compression Tolerant Hermetic Basic Building Block AgAu CryoBlock™ American Superconductor

10. The Most Robust Conductor on the Market – Fit for Industrial Handling High Strength Wire Specifications: Thickness (avg) 0.29 - 0.32 mm Width 4.0 – 4.4 mm Min Ic, Je: 115 A, 9.0 kA/cm2 125 A, 9.8 kA/cm2 135 A, 10.5 kA/cm2 145 A, 11.3 kA/cm2 Critical Bend Diameter 50mm Critical Tensile Stress: 300MPa (77K) Critical Tensile Strain: 0.35% (77K) Piece Length 100 - 400m Longer lengths available with splices American Superconductor

11. American Superconductor

12. American Superconductor

13. American Superconductor

14. NHMFL Modus Operandi Major magnet programs will be funded separately outside the core grant. Possible source of funds in NSF IMR-MIP. Programs will be structured as: Phase I: conceptual/engineering design, including technology development Phase II: detailed design and fabrication

15. Magnet Technology Development HTS technology conductor electrical characteristics conductor mechanical characteristics joint technology, soldered quench characteristics, protection LTS technology high strength conductor Nb3Sn lead structure coil form interface insulation cleaning

16. NMR Magnet Proposal Considerations Play to win. Plan around allowable proposal submission dates and competing programs.

17. 1.1 GHz Magnet Alternative Two Phase Program Schedules

18. NMR Magnet Program • Required decisions: • Continuation of HTS technology development. • Commitment to 1.1 GHz magnet program. • Submittal date of Phase I proposal. • Commitment of NHMFL interim support. • Submittal date of Phase II proposal.