SMC Design overview of the construction and project issues

SMC Plans for new SMCs for Fresca2 programJ.C. Perez

EUCARD-WP7-HFM Short Model Coil review12 December 2011

OUTLINETechnical issuesInsulation in the frame of the CERN insulation development approachRAL insulation developmentThe configuration of the 11 T SMCRMCPlan Conclusion

12/12/2011J.C. Perez / TE-MSC-MDT22Technical issues312/12/2011J.C. Perez / TE-MSC-MDTNb3Sn-NbTi Splices After SMC#1 the splice area has been redesigned to avoid local peak stresses and to improve the electrical insulationThe splicing tool has been modified to avoid relative movements between tooling and cables possible cause of breakage of filaments during soldering operationClamping tools have been produced to hold the Nb3Sn 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 leadsThe contact resistance measurement performed on the Nb3Sn/NbTi splices during SMC#3 cold tests, shows very good results (R < 1 n)The experience is being implemented in the splice area of the FRESCA2 magnet

12/12/20114J.C. Perez / TE-MSC-MDT4FRESCA2 interconnection 12/12/20115J.C. Perez / TE-MSC-MDT

5Reaction & impregnation mold 12/12/20116J.C. Perez / TE-MSC-MDTThe 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 process6Insulation in the frame of the CERN insulation development approach7J.C. Perez / TE-MSC-MDT12/12/2011 12/12/20118J.C. Perez / TE-MSC-MDT Coated spacers with Plasma Spray Al203 & Ni/Cr 80/20Insulation Tests

R6R5R4R3R2R1Central PostSpacers setR (G) @ 1000 V ( R1 to R6)R (G) @ 2500 V (R1 to R6)Central post 117352Central post 1

27352Central post 2

17352Central post 2

27352Central Post 1 after Thermal cycle @ 77 K17352Central Post 1 after Thermal cycle @ 650 0C

173528CERN cable insulation development program, a list of tasks under definition12/12/20119J.C. Perez / TE-MSC-MDTFibersDesizing: test heat process vs. chemical processSizing: palmitic acid (machine under design) vs. inorganic sylane (if they exist )E-glass vs S2-glass: how much do we gain ???TapesProcure and perform mechanical tests on possible tapesCombine mechanical tests with electrical tests on impregnated fibersMake available a proper tooling or supplier for the tape wrappingBraidingMachine ready to braid from 8 to 15 mm wide cableReady to modify for the 22 mm wide cableProcurement of S2 yarn under studyBig 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)9ObjectiveLink together the different labs in a common effort. we shareThe workThe resultsThe stock of materials101st common web platform under development at CERN12/12/2011J.C. Perez / TE-MSC-MDTFrom a possible collaboration point of view11TE-MSC-MDT magnet laboratoryTE-MSC-MDT polymer labEN-MMEMechanical testTE-MSC-MNCHV test labCERNLBNLRALFERMI12/12/2011J.C. Perez / TE-MSC-MDTCEARAL insulation development12/12/201112J.C. Perez / TE-MSC-MDTCERN has a contract with RAL for insulation development. Glass fibre insulation (Q1 2012)Braided s-glass sock 0.2 mm thick for Nb3Sn cables (10 mm and 21 mm) Coated metal islands (Q1 2012) Electrical insulating coating for stainless steel and Ti pieces (< 0.1 mm thick)Develop cyanate ester impregnation for coils (Q3 2012)Affordable, radiation hard and well bondingMake 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 Q2 2012 onwards.

12The configuration of the 11 T SMC1312/12/2011J.C. Perez / TE-MSC-MDTSMC Coil for 11T cable12/12/201114J.C. Perez / TE-MSC-MDT

Single pancake coil configurationCable dimensions: 14.7 * 1.27 mm2 * 37 turnsIss: 15950 ABpeak: 14.08 T

Courtesy of B. Auchmann14Cable Insulation for SMC11T

Base-line: E-Glass thickness 0.150, 0.075 mm x 12.7-mm wide E-glass 50% overlap.Alternative insulation methods:S2-glass tapeS2-glass sleeve (LARP)S2-glass braiding directly on the cable90 m Mica(* with E/S-glass tape90 m Mica with E/S-glass braiding (?)

*)Cablosam AP - PG90 366.20-81 by Von RollJ.C. Perez / TE-MSC-MDT12/12/201115Courtesy of M. Karppinen15RMC12/12/2011J.C. Perez / TE-MSC-MDT16From SMC (Short Model Coil) to RMC (Racetrack Model Coil) towards FRESCA217

RMC goals: test FRESCA2 cable and FRESCA2-type coils in realistic cond.ConstraintsLayer jump similar to FRESCA2Power supply limit ~20 kAMagnet OD: 560 mmSMCRMCFRESCA2J.C. Perez / TE-MSC-MDT12/12/2011Courtesy of P. FerracinRMC coil design18

Same design as SMC2 end spacers33 turns (like FRESCA2)FRESCA2-type layer jump2 easy-way + 1 hard-way bend

As a resultStraight section: 350 mm150 mm in SMCCoil length: 800 mm500 mm in SMC100 m of cable per coil 4.0 km of strand

RMC coilFRESCA2 coilJ.C. Perez / TE-MSC-MDT12/12/2011Courtesy of P. FerracinRMC magnet designFirst solution considered2 SMC coils replaced with 1 RMC coilIss (1.9 K) = 23.3 kANot possible to test coil to its limit

Final configuration2 RMC coils Iss (1.9 K) = 18.3 kABelow power supply limitBpeak = 16.0 TSignificantly higher forcesFrom 2.2 MN/m in SMC to 5.4 MN/mNew structure requiredThicker shell, new yoke design, larger bladders, larger axial rods

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SMCRMCJ.C. Perez / TE-MSC-MDT12/12/2011Courtesy of P. FerracinRMC1 double pancake vs. 2 double pancakesStill possible to test individual coils up to 20 kACorresponding to about 93% of Iss @ 4.2 K

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J.C. Perez / TE-MSC-MDT12/12/2011Courtesy of P. Ferracin

plan2112/12/2011J.C. Perez / TE-MSC-MDTNext SMC assembled coils12/12/201122J.C. Perez / TE-MSC-MDTSMC AssemblyCable TypeCable InsulationScheduledSMC#3_b PIT 14 * 1.25 mmS2-Glass sleeveFNAL typeQ1-2012SMC#11T_a

OST RRP 114/12740 * 0.7 mm75 m E-glass50 % overlapQ2-2012SMC#11T_b

OST RRP 114/12740 * 0.7 mm50 m E-glass& Mica 90 m Q2-2012SMC#4

PIT 18 * 1.00 mm

S2-Glass sleeve100 m Q3-2012SMC#5

RRP 18 * 1.00 mm

TBDQ4-201222Next RMC coils production12/12/201123J.C. Perez / TE-MSC-MDTRMC AssemblyCable TypeCable InsulationScheduledRMC#1 coil 1PIT 40 * 1.0 mmS2-Glass braidedOr according to FRESCA2 choiceQ3-2012RMC#1 coil 2PIT 40 * 1.0 mmS2-Glass braidedOr according to FRESCA2 choiceQ3-2012RMC#2 coil 1RRP 40 * 1.0 mmS2-Glass braidedOr according to FRESCA2 choiceQ4-2012RMC#2 coil 2RRP40 * 1.0 mmS2-Glass braidedOr according to FRESCA2 choiceQ4-201223Conclusions12/12/201124J.C. Perez / TE-MSC-MDTSMC lessonsImprovement required from the insulation point of viewApplication of alumina spray on metallic partsPursuing integration of the insulation program among different project and tightening the links among different labsModeling and mechanical measurementsTry to better understand apparent loss of pre-stress using simpler and ad hoc FEM models and monitoring next SMC behaviorReduce turn around timeMake available an oven dedicated to SMC coil type reaction (ongoing)Simplify coils (revise number of strain gauges on the base of 1st results)Make available a tooling capable to cover a larger variety of cable dimensionsRMC design and fabrication

24I would like to thank all members of the SMC collaboration team for their contribution to this project. 12/12/201125J.C. Perez / TE-MSC-MDTThanks for your attention !!25