HHH-AMT-Road Map for European Conductor

1. HHH-AMT-Road Map for European Conductor Conductor and Magnet have to be developed in close and interactive loop. If a conductor has a current density in the range 1000-2000 A/mm2 at field X and temperature Y, a magnet at max field X and at temperature Y can be built. The bore diameter (which defines the stored energy, the forces, the protection) has to be defined as soon as possible to make models and prototypes( ~5 years ). In DC magnets, beam losses have to be minimized by the optics scheme. No conductor in the horizontal plane (less efficiency of the Ampere-turns) . In AC magnets, the main load are the AC losses. Tools exist to calculate them. The thermal load will define the temperature margin and then the operating field (20 mW /cm3 at 1.9K ) HHH-AMT-D.Leroy-Road Map for European Conductor

2. HHH-AMT-Road Map for European Conductor • NbTi at 1.9 K 1200 A / mm2 at 11 T Margin of 1.5 K leads to Bq-1.5 T Material well specified( Fe effect can be considered for micro structure improvement and jc increase w/o long heat treatments) Magnet construction known For AC applications, filaments of 3.5 m in Cu matrix is feasible. Smaller filament size of 2 to 3.5 m needs R&D ( matrix material) • Nb Ti Ta at 1.9 K 1200 A / mm2 at 12 T Material to be developed , needs R&D (2 to 3 years) Ta content and small grain size to be controlled Needs support(1.5 M €)!!! 1 T increase has not to be neglected Magnet construction known HHH-AMT-D.Leroy-Road Map for European Conductor

3. HHH-AMT-Road Map for European Conductor • Nb3 Sn Needs R&D European goal :1500 A /mm2 at 15 T and 4.2 K (NED in 2007) Very sensitive to tensile stress/strain: avoid bending moments in cables under magnetic forces. Should we aim to small strand diameter? Has a volumetric expansion of 27 % at reaction Magnets of length 5 to 10 m to be developed (~ 8 years?) in the route wind and react. • Nb3 Al Less sensitive to stress/strain. Has the potential to be used in the route react and wind. Developments very slow. Main interest for MR in Japon HHH-AMT-D.Leroy-Road Map for European Conductor

4. HHH-AMT-Road Map for European Conductor • Mg B2 Critical Temperature of 30 K and Hc2 of 30 T.Potential of a higher temperature margin. Critical current densities still too low. Less good superconducting properties in perpendicular field Mechanical properties to be measured, methodology to be developed for this hard powder. Ways for stabilization to be found. • High Tc Bi-SCCO 2212:2000 A/mm2 at 12 T (Showa/LBNL)-Flat Jc vs B-Cable exist Je~600 A/mm2 (Nexans /OST). Significant improvement can be anticipated from optimizing conductor design, grain size and additives in Ag, overall composition, pre-annealing, melting and solidification steps of heat treatment. Engineering of heat treatments on coils to be developed. (1 M € on 4 years ) • Y-BCO HHH-AMT-D.Leroy-Road Map for European Conductor

5. HHH-AMT-Road Map for European Conductor Strand diameter 1.250 ± 0.004 mm Effective Filament diameter according to billet design < 50.0 µm Copper to non-copper volume ratio 1.25 ± 0.10 Filament twist pitch after cabling 30 ± 3 mm Filament twist direction right-handed screw Minimum critical current at 4.222 K 1636 A at 12 T 818 A at 15 T RRR (after full reaction) > 200 n-value @ 15 T and 4.2 K > 30 HHH-AMT-D.Leroy-Road Map for European Conductor

6. HHH-AMT-Road Map for European Conductor Cable width 26 mm Cable mid-thickness at 50 MPa 2.275mm Keystone angle 0.22 degrees Cable thin edge thickness 2.175 mm Cable thick edge thickness 2.375 mm Cable transposition pitch ~180 mm Number of superconducting strands 40 Critical current at 4.222 K, with field normal to broad face 29440 A at 15 T 58880 A at 12 T Minimum critical current at 4.222 K of extracted strand 736 A at 15 T 1472 A at 12 T n-value @ 15 T and 4.222 K > 20 Residual resistance ratio before reaction ≥ 70 after reaction ≥ 120 Cable transposition direction left-handed screw thread Minimum unit length 145 m HHH-AMT-D.Leroy-Road Map for European Conductor

7. HHH-AMT-Road Map for European Conductor HHH-AMT-D.Leroy-Road Map for European Conductor