1. 1 A Joint Proposal for US-Japan Cooperation Program Proposal to JSPS US-Japan collaboration fund R&D of superconducting magnet technology for high intensity muon beam line KEK – ARL, Cryogenics Science Center T. Ogitsu, N. Kimura, T. Nakamoto, K. Sasaki, K. Tanaka, A. Yamamoto, – IPNS, Cryogenics Group Y. Makida, T. Okamura FNAL – Technical Div. M. Lamm, A. Zlobin, V. Kashikhin, E. Barzi, S. Feher, J. Tompkins

2. Term 2009~2014 Phase I (mainly 2009~2011) – Near term – Projected for Mu2e and COMET Phase II (mainly 2011~2014) – Long term – Projected for future high intensity muon beam line – Eventually for Neutrino Factory and Muon Collider

3. Phase I R&D Mu2e COMET Pion Capture Solenoid R&D for Mu2e and COMET Requirement High Field – More pion to capture – More (better) conductor – Larger stored energy ~5T for COMET and Mu2e High Radiation – High Power Beam – Heat Load – Radiation Damage ~10 W for COMET

4. High yield strength A l s t a b i l i z e d c o n d u c t o r N b T i b a s e f o r f i e l d u p t o 5 T Superconductor requires good normal conductor as stabilizer and quench protection Copper is the standard – Density: 8920 Kg/m 3 Aluminum is also a good normal conductor – Density: 2700 Kg/m 3 – More transparent against radiation – Can provide less heat load with the same stabilization property

5. High Yield Strength Al stabilized Conductor R&D For High Energy Physics – Higher Field ： > 5 Tesla – Larger Size ： Diameter 〜 10m Combination of Various Technology – ATLAS Al Ni Alloy Ni-0.5 ~ 1 % – CMS-Hybrid Support A6058 -->> A7020 Y.S.(0.2%) = 400 MPa RRR = ~ 400

6. 6 An R&D Work using ATLAS-CS Conductor + A6061-T6 T.S. is > 50 % reinforced with A6061 using Electron Beam, and Laser Beam Welding LBW may be a potential technology EBW, LBW Laser Beam Welding

7. Phase I R&D: Prototype Solenoid Fabricate prototype pion capture solenoid Test items – Mechanical stability – Heat load stability – Quench protection including coupling

8. Phase I R&D Plan 200920102011 Conductor R&D Design Proto Conductor Fab. Coil R&D Conceptual Design Proto Coil Fab. Proto Coil Test Real Magnet Detail Design Magnet Production

9. Phase II R&D Aim for future high intensity muon beam line – Eventually neutrino factory or muon collider More Muon – Higher Field (20 T and more) – Higher Beam Intensity = Higher Heat Load Advance conductor – Nb3Sn, Nb3Al, MgB2, YBCO, BSCCO – Aluminum stabilizer or aluminum jacket cable in conduit cable Study on Design Issues associated with using advanced conductor

10. Conductor Choice for Higher Field and Higher Stability MaterialTcTc H c 2 ( T= 4.2 K) Mass Density Nb-Ti9 K10 T6000 Kg/m 3 Nb 3 Sn18 K28 T7800 Kg/m 3 Nb 3 Al18.5 K30 T7200 Kg/m 3 MgB 2 39 K60 T2500 Kg/m 3 YBCO90 K> 50 T5400 Kg/m 3 BSCCO110 K> 50 T6300 Kg/m 3

11. A15 (Nb3Al, Nb3Sn) For now the best candidate for high field application Nb3Sn strand Nb3Al strand Al stabilized Nb3Al Conductor (NIFS)

12. Toward Higher Beam Power Cable in conduit – Removal of large heat load Nb 3 Sn Rutherford cable

13. MgB2 Monel 400 sheathed Diameter: 1.13mm Composition MgB 2 (Vol %)14.6 Fe (Vol %)10.8 Cu (Vol %)13.8 Ni (Vol %)15.8 Monel 400 (Vol %)45.0 Monel 400 sheathed Diameter: 1.13mm Composition MgB 2 (Vol %)14.6 Fe (Vol %)10.8 Cu (Vol %)13.8 Ni (Vol %)15.8 Monel 400 (Vol %)45.0 Cost: 3€/m Commercial products are now being available. Low field performances are good up to 20 K, 2 T High field field performance are under development

14. High Tc Conductors 22 T already achieved Possibility to go beyond

15. Issue Needs stabilizer for stability and quench protection Need large conductor for higher operation current, i.e. less inductance Aluminum stabilizer? Aluminum jacket cable in conduit? Hybrid magnet structure for efficiency

16. R&D Schedule & Budget 200920102011201220132014 Phase IConductor R&D 20MJYen Proto Coil 25MJYen Proto Coil Test 10MJYen Proto Coil Test 2MJYen Test Analysis 1MJYen Test Analysis 1MJYen Phase IIConductor Basic R&D 5MJYen Conductor Basic R&D 5MJYen Conductor R&D 20MJYen Proto Cond.Fab. 28MJYen Proto Coil Fab. 29MJPYen Proto Coil Test 20MJYen Cont.10MJYen5MJYen 4MJYen Travel3MJYen Total38MJYen 28MJYen

17. Other staff Transport Solenoid R&D at KEK

18. J-PARC Muon Beam Line Field; ~2T Aparture; ~0.4 m Limited Access to shielded area – Refrigerator must be outside of shield – Limited Space for the refrigerators – Long distance to cold head to coil front – Conduction Cooling with Higher Temperature

19. Trial Winding of Curved Section with MgB2 conductor Purchase two kinds of MgB2 conductor from Columbus SC – 1 is the 1.13 mm diameter round wire Will be wound by a company – 2 is the 1.5 * 2.5 mm square wire Will be wound by Nakahara and Adachi at KEK They will be wound this winter and Tested in next spring R&D Coil made at KEK in house NbTi Already wound Test just started MgB2 version is also planned

20. R&D on Transport SC Solenoid Coil by company will be wound till Mar. R&D on trim dipole coil