SMC Plans for new SMCs for Fresca2 program J.C. Perez EUCARD-WP7-HFM Short Model Coil review 12 December 2011

OUTLINE Technical issues Insulation in the frame of the CERN insulation development approach RAL insulation development The configuration of the 11 T SMC RMC Plan Conclusion 12/12/2011 J.C. Perez / TE-MSC-MDT 2

TECHNICAL ISSUES 3 12/12/2011 J.C. Perez / TE-MSC-MDT

Nb 3 Sn-NbTi Splices After SMC#1 the splice area has been redesigned to avoid local peak stresses and to improve the electrical insulation The splicing tool has been modified to avoid relative movements between tooling and cables possible cause of breakage of filaments during soldering operation Clamping tools have been produced to hold the Nb 3 Sn cable when cutting them to their final length Several quenches were detected in the NbTi leads during SMC#3 cold tests. The clamping system of these leads has to be improve for the next magnets. A thermal/mechanic copper sheet stabilizer will be implemented in the interconnection design to back-up the leads The contact resistance measurement performed on the Nb 3 Sn/NbTi splices during SMC#3 cold tests, shows very good results (R < 1 n Ω ) The experience is being implemented in the splice area of the FRESCA2 magnet 12/12/ J.C. Perez / TE-MSC-MDT

FRESCA2 interconnection 12/12/ J.C. Perez / TE-MSC-MDT

Reaction & impregnation mold 12/12/ J.C. Perez / TE-MSC-MDT The cavity of the reaction mold has been increased to allow cable expansion during the heat treatment process + 4% in the horizontal direction + 2% in the vertical direction Holes have been added to the impregnation mold to garanty an easier penetration of the resin during the impregnation process

INSULATION IN THE FRAME OF THE CERN INSULATION DEVELOPMENT APPROACH 7 J.C. Perez / TE-MSC-MDT 12/12/2011

8 J.C. Perez / TE-MSC-MDT Coated spacers with Plasma Spray Al & Ni/Cr 80/20 Insulation Tests Coated spacers with Plasma Spray Al & Ni/Cr 80/20 Insulation Tests R6 R5 R4 R3 R2 R1 Central PostSpacers set R (G Ω 1000 V ( R1 to R6) R (G Ω 2500 V ( R1 to R6) Central post Central post Central post Central post Central Post 1 after Thermal 77 K Central Post 1 after Thermal C 17352

CERN cable insulation development program, a list of tasks under definition 12/12/ J.C. Perez / TE-MSC-MDT Fibers ◦ Desizing: test heat process vs. chemical process ◦ Sizing: palmitic acid (machine under design) vs. inorganic sylane (if they exist …) ◦ E-glass vs S2-glass: how much do we gain ??? Tapes ◦ Procure and perform mechanical tests on possible tapes ◦ Combine mechanical tests with electrical tests on impregnated fibers ◦ Make available a proper tooling or supplier for the tape wrapping Braiding ◦ Machine ready to braid from 8 to 15 mm wide cable ◦ Ready to modify for the 22 mm wide cable ◦ Procurement of S2 yarn under study ◦ Big question to solve the sizing Ovens to test fibers ◦ Very small oven available (diameter 40 mm length 40 mm) ◦ New oven ordered (160 mm diameter and useful length for this kind of test 350 mm)

Objective Link together the different labs in a common effort. we share ◦ The work ◦ The results ◦ The stock of materials 10 1 st common web platform under development at CERN 12/12/2011 J.C. Perez / TE-MSC-MDT

From a possible collaboration point of view 11 TE-MSC- MDT magnet laboratory TE-MSC- MDT polymer lab EN-MME Mechanical test EN-MME Mechanical test TE-MSC- MNC HV test lab TE-MSC- MNC HV test lab 12/12/2011 J.C. Perez / TE-MSC-MDT

RAL insulation development 12/12/ J.C. Perez / TE-MSC-MDT CERN has a contract with RAL for insulation development. 1.Glass fibre insulation (Q1 2012) ◦ Braided s-glass sock 0.2 mm thick for Nb 3 Sn cables (10 mm and 21 mm) 2.Coated metal islands (Q1 2012) ◦ Electrical insulating coating for stainless steel and Ti pieces (< 0.1 mm thick) 3. Develop cyanate ester impregnation for coils (Q3 2012) ◦ Affordable, radiation hard and well bonding 4. Make a SMC (RMC) coil with 40 strand cable and using the braided s-glass, coated islands and cyanate ester (2013) The braided s-glass and the coated islands are intended for usage in Fresca2 and will this be tested in SMCs (RMCs) for qualification from Q onwards.

THE CONFIGURATION OF THE 11 T SMC 13 12/12/2011 J.C. Perez / TE-MSC-MDT

SMC Coil for 11T cable 12/12/ J.C. Perez / TE-MSC-MDT Single pancake coil configuration Cable dimensions: 14.7 * 1.27 mm 2 * 37 turns I ss : AB peak : T Courtesy of B. Auchmann

Cable Insulation for SMC11T Base-line: ◦ E-Glass thickness – 0.150, mm x 12.7-mm wide E-glass 50% overlap. Alternative insulation methods: ◦ S2-glass tape ◦ S2-glass sleeve (LARP) ◦ S2-glass braiding directly on the cable ◦ 90 µm Mica (* with E/S-glass tape ◦ 90 µm Mica with E/S-glass braiding (?) *) Cablosam® AP - PG by Von Roll J.C. Perez / TE-MSC-MDT 12/12/ Courtesy of M. Karppinen

RMC 12/12/2011J.C. Perez / TE-MSC-MDT16

From SMC (Short Model Coil) to RMC (Racetrack Model Coil) towards FRESCA2 17 RMC goals: test FRESCA2 cable and FRESCA2-type coils in realistic cond. Constraints 1.Layer jump similar to FRESCA2 2.Power supply limit ~20 kA 3.Magnet OD: 560 mm SMC RMC FRESCA2 J.C. Perez / TE-MSC-MDT 12/12/2011 Courtesy of P. Ferracin

RMC coil design 18 Same design as SMC ◦ 2 end spacers ◦ 33 turns (like FRESCA2) FRESCA2-type layer jump ◦ 2 easy-way + 1 hard-way bend As a result ◦ Straight section: 350 mm  150 mm in SMC ◦ Coil length: 800 mm  500 mm in SMC ◦ 100 m of cable per coil  4.0 km of strand RMC coil FRESCA2 coil J.C. Perez / TE-MSC-MDT 12/12/2011 Courtesy of P. Ferracin

RMC magnet design First solution considered ◦ 2 SMC coils replaced with 1 RMC coil  I ss (1.9 K) = 23.3 kA  Not possible to test coil to its limit Final configuration ◦ 2 RMC coils  I ss (1.9 K) = 18.3 kA  Below power supply limit  B peak = 16.0 T ◦ Significantly higher forces  From 2.2 MN/m in SMC to 5.4 MN/m ◦ New structure required  Thicker shell, new yoke design, larger bladders, larger axial rods 19 SMC RMC J.C. Perez / TE-MSC-MDT 12/12/2011 Courtesy of P. Ferracin

RMC 1 double pancake vs. 2 double pancakes Still possible to test individual coils up to 20 kA  Corresponding to about 93% of I 4.2 K 20 J.C. Perez / TE-MSC-MDT 12/12/2011 Courtesy of P. Ferracin

PLAN PLAN 21 12/12/2011 J.C. Perez / TE-MSC-MDT

Next SMC assembled coils 12/12/ J.C. Perez / TE-MSC-MDT SMC AssemblyCable TypeCable InsulationScheduled SMC#3_bPIT 14 * Ø 1.25 mm S2-Glass sleeve FNAL type Q SMC#11T_aOST RRP 114/ * Ø 0.7 mm 75 µm E-glass 50 % overlap Q SMC#11T_bOST RRP 114/ * Ø 0.7 mm 50 µm E-glass & Mica 90 µm Q SMC#4PIT 18 * Ø 1.00 mm S2-Glass sleeve 100 µm Q SMC#5RRP 18 * Ø 1.00 mm TBDQ4-2012

Next RMC coils production 12/12/ J.C. Perez / TE-MSC-MDT RMC AssemblyCable TypeCable InsulationScheduled RMC#1 coil 1PIT 40 * Ø 1.0 mm S2-Glass braided Or according to FRESCA2 choice Q RMC#1 coil 2PIT 40 * Ø 1.0 mm S2-Glass braided Or according to FRESCA2 choice Q RMC#2 coil 1RRP 40 * Ø 1.0 mm S2-Glass braided Or according to FRESCA2 choice Q RMC#2 coil 2RRP 40 * Ø 1.0 mm S2-Glass braided Or according to FRESCA2 choice Q4-2012

Conclusions 12/12/ J.C. Perez / TE-MSC-MDT SMC lessons ◦ Improvement required from the insulation point of view  Application of alumina spray on metallic parts  Pursuing integration of the insulation program among different project and tightening the links among different labs ◦ Modeling and mechanical measurements  Try to better understand apparent loss of pre-stress using simpler and ad hoc FEM models and monitoring next SMC behavior ◦ Reduce turn around time  Make available an oven dedicated to SMC coil type reaction (ongoing)  Simplify coils (revise number of strain gauges on the base of 1 st results) ◦ Make available a tooling capable to cover a larger variety of cable dimensions  RMC design and fabrication

I would like to thank all members of the SMC collaboration team for their contribution to this project. 12/12/ J.C. Perez / TE-MSC-MDT Thanks for your attention !!