Muon Magnet R&D Status

1. Muon Magnet R&D Status Alexander Zlobin MCTF Meeting 19 March 2009 1

2. Muon Magnet R&D Directions • Formulated by the MC 5-year plan • Focus on the muon cooling channel magnets • Helical solenoids for 6D muon beam cooling • Very high field solenoids for the final muon cooling • Magnet R&D • Conceptual design studies of Cooling Channel Magnet Systems • Helical solenoids for HCC “front” and “far” ends • 50 T solenoid • Magnet Technology Development • Short HS models • HTS solenoid inserts • R&D for SC Materials in support of magnet program (with National Labs and Industry) • Participation in National HTS Program Alexander Zlobin MCTF Meeting 19 March 2009 2

3. HCC Magnet System Design Studies • The helical solenoid concept (Fermilab) • Ring coils follow the helical beam orbit produsing solenoi-dal, helical D and Q fields • Multisection HCC • Wide range of fields, helical periods, apertures • Room for RF system • Field tuning more complicate at high fields • NbTi, Nb3Sn/Nb3Al and HTS in final stage • Straight solenoid concept does not work for high-field/small-aperture sections Alexander Zlobin MCTF Meeting 19 March 2009 3

4. HS Front End Objectives: • Field components for given geometry (which allows installation RF system) • Superconductor choice – Nb3Sn, NbTi, conductor grading • Mechanical structure and cryostat • Operation margin • Coil cooling • Quench protection Work in progress Alexander Zlobin MCTF Meeting 19 March 2009 4

5. HS Far End Objectives: • Superconductor choice – LTS, HTS, hybrid, conductor grading • Field components for given geometry • Operation margin Work in progress Alexander Zlobin MCTF Meeting 19 March 2009 5

6. HS Technology R&D • Complex magnet • significant magnetic forces and stored energy, • must eventually incorporate RF => 4-coil Helical Solenoid Model Program • Goals: • validate mechanical structure • fabrication methods • study quench performance and margins, field quality, quench protection Alexander Zlobin MCTF Meeting 19 March 2009 6

7. 4-Coil Model HSM01 Coil is wound from Rutherford-type superconducting cable (SSC) on a stainless steel bobbin The short model consists of four superconducting coils with support structures and end flanges Outer stainless steel collar rings provide the coil support and intercept the radial Lorentz forces At high current of 14 kA it provides the fields, forces, and stresses of the long HS Alexander Zlobin MCTF Meeting 19 March 2009 7

8. HSM01 Test Results • Test plan: • Magnetic measurements at room and LHe temperatures • Quench performance HS Model Long HS Alexander Zlobin MCTF Meeting 19 March 2009 8

9. Coil 4 9turns Coil 3 9 turns Voids Coil 2 10 turns Thick epoxy Coil 1 9 turns HSM01 Autopsy Alexander Zlobin MCTF Meeting 19 March 2009 9

10. HSM02 NbTi 4-coil model 2 The base line of magnetic and mechanical design is the same as for HSM01 Improved • mechanical structure and coil insulation • cable geometry and insulation • Winding and impregnation procedures SSC cable re-sizing experiment: • Thick side 1.600mm =>1.416mm • Thin side 1.375mm =>1.271mm • Avg. 1.413mm =>1.343mm • Avg Width 12.36mm =>12.945mm Fabrication status: • Ready to start part procurement • Test in November 2009 HSM03, HSM04 design features are being discussed Alexander Zlobin MCTF Meeting 19 March 2009 10

11. Hybrid HS Model HTS:YBCO tape HTS: Bi-2212 strand and cable • Conceptual design of Hybrid HS model • Develop the technology for mechanical design, fabrication and assembly • Develop the technology for quench protection Alexander Zlobin MCTF Meeting 19 March 2009 11

12. 50 T Solenoid Conceptual Design Basic Parameters • Inner bore diameter 50 mm • Length 1 meter • Fields 30 T or higher  • HTS materials Key design issues: • superconductor Jc • effect of field direction on Ic in case of HTS tapes • stress management • quench protection • cost Conceptual design: • hybrid coil design • coil sections Work in progress: • Conductor • Quench protection NbTi Nb3Sn B BSCCO Coil radius, m Alexander Zlobin MCTF Meeting 19 March 2009 12

13. 50 T Solenoid Technology R&D • Build and test smaller HTS and HTS/Nb3Sn hybrid solenoid models • Field range: up to 20-25 T • Emphasis on HTS strands, tapes and cables • Nb3Sn and Nb3Al strand and cable R&D is supported by other programs (DOE, LARP, NIMS/FNAL/KEK, CARE, etc.) • HTS material: BSCCO (G1) or YBCO (G2) • Conductor type: round strands, cables or tapes • Technologies: react-&-wind or wind-&-react Alexander Zlobin MCTF Meeting 19 March 2009 13

14. Strand and Tape Samples Alexander Zlobin MCTF Meeting 19 March 2009 14

15. HTS/HFS Conductor R&D Monitoring industry progress to provide input to magnet design. This includes studies of the engineering current density (Je) as a function of: • magnetic field => new data up to 28 T (FNAL-NIMS collaboration); • temperature => data from superfluid He to nitrogen temperature; • field orientation (for anisotropic tapes) => new data; • bending strain => new equipment was designed and commissioned, first results; • longitudinal strain => new fixture was designed and being procured; • transverse pressure => setup is available. Alexander Zlobin MCTF Meeting 19 March 2009 15

16. High Field HTS Tests Alexander Zlobin MCTF Meeting 19 March 2009 16

17. Current lead Support Insulation Skin Coils Support ring Nut Insert Coil R&D The first phase of the coil program is based on HTS tapes and R&W technology. Focus is on single and multi-layer pancake coils. Test in a 14T/16T solenoid. • A modular HTS Insert Test Facility was designed and is being procured to assemble and test up to 14 double-layer pancake coils within the 14T/16T solenoid (B>20 T) => Splice techniques for tapes were studied => Single and double-layer pancake coils made of YBCO and Bi-2223 were built and tested For the second phase of the coil program, larger multi-section HTS coils will be fabricated and tested to achieve higher magnetic fields and force levels. Alexander Zlobin MCTF Meeting 19 March 2009 17

18. HTS Coils Summary Alexander Zlobin MCTF Meeting 19 March 2009 18

19. Summary • Muon magnet program is making progress in all key directions • Magnet design studies • Technology development • HTS material R&D • We collaborate with DOE labs, industries and Universities through National HTS Conductor program and SBIR programs • New results will be reported in several papers at PAC’2009, CEC/ICMC’2009 and MT-21 • Stable funding and manpower resources are critical to accomplish the 5-year Muon magnet R&D plan Alexander Zlobin MCTF Meeting 19 March 2009 19