1. MQXF Design and Conductor Requirements P. Ferracin MQXF Conductor Review November 5-6, 2014 CERN

2. Outline Overview of MQXF design Baseline strand and insulated cable Coil design and magnetic analysis Magnet parameters Mechanical analysis and quench protection Possible fine tune of cable dimensions 5/11/2014 Paolo Ferracin2

3. Overview of MQXF design 5/11/2014 Paolo Ferracin3 Target: 140 T/m in 150 mm coil aperture To be installed in 2023 (LS3) Q1/Q3 (by US LARP collaboration) – 2 magnets with 4.0 m of magnetic length within 1 cold mass Q2 (by CERN) – 1 magnet of 6.8 m within 1 cold mass, including MCBX (1.2 m) Baseline: different lengths, same design – Identical short model magnets SQXF by E. Todesco

4. From LARP HQ to MQXF Strand, cable and coil The aperture/cable width is approximately maintained – Aperture from 120 mm to 150 mm – Cable from 1.5 to 1.8 mm width – Similar stress with +30% forces Same coil lay-out: 4-blocks, 2-layer with same angle Optimized stress distribution Strand increase from 0.8 mm to 0.85 mm, with same filament size – Maximum # of strand: 40 Lower J overall from quench protection (from 580 to 480 A/mm 2 ) 5/11/2014 Paolo Ferracin4 HQ MQXF

5. From LARP HQ to MQXF Magnet design Same structure concept Pre-load capabilities of HQ design qualified and successfully tested Larger OD: from 570 to 630 mm Additional accelerator features Larger pole key for cooling holes Cooling channels Slot for assembly/alignment LHe vessel and welding blocks and slots 5/11/2014 Paolo Ferracin5 HQ MQXF

6. Overview of MQXF design 5/11/2014 Paolo Ferracin6 OD: 630 m SS shell, 8 mm for LHe containment Al shell, 29 mm thick Iron yoke – Cooling holes (77 mm) – Slots of assembly/alignment Iron Master plates – 58 mm wide bladder Iron pad Al bolted collars – Coil alignment with G10 pole key Ti alloy poles

7. Overview of MQXF design 5/11/2014 Paolo Ferracin7 OD: 630 m SS shell, 8 mm for LHe containment Al shell, 29 mm thick Iron yoke – Cooling holes (77 mm) – Slots of assembly/alignment Iron Master plates – 58 mm wide bladder Iron pad Al bolted collars – Coil alignment with G10 pole key Ti alloy poles

8. MQXF magnet design 5/11/2014 Paolo Ferracin8

9. Outline Overview of MQXF design Baseline strand and insulated cable Coil design and magnetic analysis Magnet parameters Mechanical analysis and quench protection 5/11/2014 Paolo Ferracin9

10. 0.85 mm strand Filament size <50 μm OST 132/169: 48-50 μm Bruker PIT 192: 42 μm Cu/Sc: 1.2  0.1  55% Cu Critical current at 4.2 K and 15 T – 361 A at 15 T (632 A at 12 T) MQXF strand (from CERN technical specification document) 5/11/2014 Paolo Ferracin10 Bruker PIT strand, 192 OST RRP strand, 132/169

11. MQXF baseline cable and insulation 5/11/2014 Paolo Ferracin11

12. MQXF baseline cable 40-strand cable Mid – thickness after cabling – 1.525 +/- 0.010 mm – Thin/thick edge: 1.438 /1.612 mm Width after cabling – 18.150 +/- 0.050 mm Keystone angle – 0.55 +/- 0.10 deg. – Pitch length – 109 mm – SS core 12 mm wide and 25 μm thick Assumed expansion during reaction – 4.5% in thickness: ~70 μm, same keystone angle – 2% in width: ~360 μm Mid – thickness after reaction – 1.594 mm – Thin/thick edge: 1.505/1.682 mm Width after reaction – 18.513 5/11/2014 Paolo Ferracin12 PIT cable RRP cable 70 μm 360 μm

13. Dimensional changes during heat treatment Unconfined cables and strands (RRP) at LBNL – axial contraction: 0.1 to 0.3 % – thickness increase: 1.5 to 4 % – width increase: 1.5 to 2 % Data on PIT strands and cables (FRESCA2) – larger axial contraction, comparable cross-section increase In HQ01, only 1-2% space for expansion left in design – Clear signs of over compressed and degraded coils So in HQ02, reduction of strand diameter (0.8  0.778 mm) – Thickness: 4.5% 29 μm (HQ01) to 65 μm (HQ02) – Width: 2% – Very good HQ02 quench performance Same assumptions used for MQXF – No signs of over-compression in first coils – Work in progress: Ten stack measurements at CERN and MQXF LARP coil 1 cross- section measurements at LBNL 5/11/2014 Paolo Ferracin13

14. Cable insulation AGY S2-glass fibers 66 tex with 933 silane sizing 32 (CERN, CGP) or 48 (LARP, NEW) coils (bobbins) Variables: # of yarn per coil and of picks/inch Target:  150 μm per side (145  5 μm) at 5 MPa, average 3 cycles 5/11/2014 Paolo Ferracin14 SampleIns. Cable thickness (mm)Bare cable thick/ (mm)Insulation thick. (mm) 001_11.8221.530146 001_21.8231.531146 001_31.8211.530146 101_11.8171.531143 101_31.8161.531143 102_1 1.8211.531145 102_2 1.8191.531144 102_3 1.8231.531146

15. Tooling design Cable dimension after reaction and 150 μm thick insulation Coil cured in larger cavity Coil closed in reaction fixture in larger cavity Coil after reaction and during impregnation in nominal cavity Theoretical pressure ~5 MPa 5/11/2014 Paolo Ferracin15

16. Outline Overview of MQXF design Baseline strand and insulated cable Coil design and magnetic analysis Magnet parameters Mechanical analysis and quench protection 5/11/2014 Paolo Ferracin16

17. Coil design and magnetic analysis Two-layer – four-block design Criteria for the selection – Maximize gradient and # of turns (protection) – Distribute e.m. forces and minimize stress Result: 22+28 = 50 turns All harmonics below 1 units at R ref = 50 mm 6 blocks in the ends Iron pad removed with reduced length 1% peak field margin in the end 5/11/2014 Paolo Ferracin17

18. 18 Persistent currents 184/30/2014 Updated estimates from previous conductor review using magnetization measurements of actual QXF 169 wires performed at Ohio State University Harmonics are provided for second up-ramp following a pre-cycle corresponding to the one used for strand measurements Measured magnetization (OSU)Calculated b 6 (after pre-cycle)

19. 19 Persistent-current effect evaluation 194/30/2014 Persistent current harmonics b6b6 b 10 NominalD(+20%M)NominalD(+20%M) 1.0 kA (injection)-10.0-2.43.4 +0.8 17.5 kA (high field)-0.97-0.12-0.10.0 Effect of ±20% magnetization on b 6, b 10 included Nominal b 6 value of -10 units can be adjusted using current reset level during pre-cycle Dynamic aperture simulations have validated a persistent current b 6 up to 20 units at injection Present value of magnetization average and spread are compatible with field quality requirements For future study: assessment of the variability in wire magnetization and resulting uncertainty and random harmonics

20. Coil design and magnetic analysis Magnet lengths 5/11/2014 Paolo Ferracin20 Magnetic length RT = 1198 mm

21. Coil design and magnetic analysis Magnet lengths 5/11/2014 Paolo Ferracin21 Short modelQ1/Q3 (half unit)Q2 Magnetic length [mm] at 293 K 119840126820.5 Magnetic length [mm] at 1.9 K 1194.440006800 “Good” field quality [m]0.53.36.1 Coil physical length [mm] at 293 K 151043247132.5 Iron pad length [mm] at 293 K97537896597.5 Yoke length [mm] at 293 K155043647172.5 Longitudinal thermal contraction = 3 mm/m (as LHC magnets)

22. Coil design and magnetic analysis Conductor quantities 5/11/2014 Paolo Ferracin22 Short modelQ1/Q3 (half unit)Q2 Cable length per coil [m] (Roxie) 126407687 Cable length per coil [m] (with margin)150450710 Strand per coil [km] (with margin)6.318.930.0 Strand per coil [kg] (with margin)3295150 Strand length = cable length * 40 * 1.05 1 km of 0.85 mm strand: 5 Kg.

23. Outline Overview of MQXF design Baseline strand and insulated cable Coil design and magnetic analysis Magnet parameters Mechanical analysis and quench protection 5/11/2014 Paolo Ferracin23

24. Superconductor properties Virgin strand, no self field correction Godeke’s parameterization 5/11/2014 Paolo Ferracin24 2450 at 12 T 1400 at 15 T 2040 at 15 T 3270 at 12 T 632 at 12 T 361 at 15 T 527 at 15 T 844 at 12 T Ca1*41.24T Ca2* = 1034 x Ca1*42642T eps_0,a0.250% Bc2m*(0)31.50T Tcm*15.34K C*1541TA p0.5 q2 Strain=-0.20%

25. Magnet parameters Self field corr. (ITER barrel) 0.429 T/kA 5% cabling degradation Operational grad.: 140 T/m I op : 17.5 kA B peak_op : 12.1 T 80-81% of I ss at 1.9 K G ss : 171 T/m I ss : 21.6 kA B peak_ss : 14.7 T Stored energy: 1.3 MJ/m Inductance: 8.2 mH/m 5/11/2014 Paolo Ferracin25 Impact of higher I max strand – +10% increase in critical current  about +3% in I ss

26. Magnet parameters Temperature margin (K) Peak field (T) 5/11/2014 Paolo Ferracin26

27. Outline Overview of MQXF design Baseline strand and insulated cable Coil design and magnetic analysis Magnet parameters Mechanical analysis and quench protection 5/11/2014 Paolo Ferracin27

28. Mechanical analysis Optimization of dimensions and locations of new features ≥2 MPa of contact pressure at up to 155 T/m (~90% of I ss ) Peak coil stress: -160/-175 MPa Strain effect not included in I ss computation Similar stress as HQ ~20% of margin 5/11/2014 Paolo Ferracin28 Inner layer Outer layer

29. Quench protection 5/11/2014 Paolo Ferracin29 Protection studied in the case of 2 magnets in series (16 m) protected by one dump resistor (48 mΩ, 800 V maximum voltage) – Voltage threshold: 100 mV – Cu/Non-Cu: 1.2 – Validation time: 10 ms – Protection heaters on the outer and on the inner layer – Dynamic effects on the inductance have been considered – Quench back has not been considered (conservative assumption) Hot spot T (QLASA simulation) with 1.2 Cu/Non-Cu ratio: ~263 K Negligible effect (~6-7 K) from – RRR, from 100-200 – Cu/non-Cu ratio, from 1.1 to 1.2

30. Impact of cable dimensions optimization Up to 20 μm of thickness increase with same keystone angle – Compensated by insulation thickness from 150 to 140 μm  20 μm – “Transparent” modification, no impact on schedule More than 20 μm of thickness increase and/or change of keystone angle – Example: from 0.55 to 0.4 deg., with same mid- thickness Thin edge from 1.438 to 1.462 mm  25 μm – Considering 28 turns  700 μm on the outer layer – Change of wedges/pole/end-spacers 8-9 months from new cable geometry to beginning of winding – 2D-3D magnetic analysis – New coil CAD model – Procurement, inspection, coating 5/11/2014 Paolo Ferracin30 22+28 = 50 turns

31. Conclusions Current density of ~2500 A/mm 2  ~80 % of I ss – Reasonable margin, probably the most critical parameter 10% of critical strand current  3% of load-line margin Cu/non-Cu of 1.2 – Safe margin for protection Filament size <50 μm – Same filament size as one used in HQ02 successfully tested – Aspects related to field quality are not critical Cored cable required for reduction of dynamics effects (as in HQ02) 5/11/2014 Paolo Ferracin31

32. Appendix 5/11/2014 Paolo Ferracin32

33. MQXF project schedule 5/11/2014 Paolo Ferracin33 Short model program: 5 CERN-LARP models, 2014-2016 – Coil fabrication starts in 02-03/2014 – First magnet test (SQXF1) in 07/2015 (3 LARP coils, 1 CERN coil) Long model program: 2 (CERN) + 3 (LARP) models, 2015-2018 – Coil fabrication starts in 2015: 02 (LARP), 10 (CERN) – First magnet test in 08/2016 (LARP) and 07/2017 (CERN) Series production: 10 (CERN) + 10 (LARP) cold masses, 2018-2021 – Coil fabrication starts in 01/2018 – First magnet test in 10/2018

34. Impact of cable dimensions optimization CERN MQXF current schedule 5/11/2014 Paolo Ferracin34 20142015201620172018 RRP short model 1 RRP short model 2 PIT short model 1 RRP long model 1 PIT long model 1

35. Persistent current harmonics in HQ Validation of analysis method using HQ01 (54/61+108/127) and HQ02 X. Wang Magnetization data (OSU) HQ01 magnetization harmonics HQ02 magnetization harmonics Skew sextupole, HQ01 vs HQ02

36. Sub-element size as a function of stack

37. 37 Magnetization measurement of QXF strands X. Wang, D. R. Dietderich, A. Ghosh, A. Godeke, G. Sabbi 375/11/2014 132/169 round wire and 108/127 extracted strand samples provided by BNL Ti-Ternary, reduced-Sn 108/127 XS132/169 RW d wire before HT mm 0.85 Cu/non-Cu ratio - 1.171.19 d sub (geometric) μmμm 5751 J c (non-Cu, 4.2 K, 11 T) A/mm 2 32733317 Measurements performed by Mike Sumption and Xingchen Xu at OSU Commercial Physical Property Measurement System 1.9 K Field perpendicular to the sample length Paolo Ferracin

38. 38 Magnetization comparison 385/11/2014 As measured108/127 Scaled by 89% (51/57) Similar J c (B) for both samples (difference within 1.5% between 10 T and 11.5 T) Magnetization scales with sub-element diameter Paolo Ferracin

39. 39 Persistent-current effect in QXF 395/11/2014 Updated estimation on the persistent-current effect Latest QXF cross section/iron (MT-23) Actual magnetization of QXF 169 wire Consider ± 10% of uncertainty of the magnetization I (A)100%-10%+10% 1000 1 0.02%-0.01% 1500 1 0.07%-0.07% 17500 1 0.00% ΔTF with ± 10% magnetization change Paolo Ferracin

40. 40 b 6 and b 10 405/11/2014 I (A)100%-10%+10% 1000-10.0-8.8-11.2 1500-25.5-22.7-28.3 17500-0.61-0.55-0.67 Geometric and saturation effect removed ±10% magnetization translates to ±12% of b 6 and b 10 at low field, ±10% at nominal field but negligible (tighter tolerance for low field?) b6b6 b 10 I (A)100%-10%+10% 10003.43.03.8 15002.42.22.6 17500-0.02 Paolo Ferracin

41. Persistent current harmonics in QXF TF b6b6 b 10 b 14 b 18 T/m/kAUnit at R ref = 50 mm 108/127 -0.0368-19.34.9-0.80.0 144/169 -0.0330-16.44.2-0.70.0 90%85%86% 187% 108/127 -0.0683-32.33.7-0.8-0.0 144/169 -0.0592-27.73.2-0.7-0.0 87%86%87% 85% 108/127 -0.0021-1.30.0-0.00.0 144/169 -0.0018-1.10.0-0.00.0 87% 86%87% 1 kA, ~ injection Second up-ramp data 1.5 kA, negative peak 17.3 kA, nominal level Given the same J c, harmonics due to magnetization reduce by ~ 14%, consistent with the sub-element size reduction X. Wang

42. Margin 5/11/2014 Paolo Ferracin42

43. SQXF plan and schedule Tests 1st generation coils First LARP coil mirror test in 12/2014 First CERN coil mirror test (mirror) in 04/2015 First magnet test (SQXF1) in 05/2015 – Assembled and tested by LARP with 3 LARP coils and 1 CERN coil Then SQXF1b (LARP), SQXF2 (CERN), SQXF2b in series (2015-2016) All the coil fabricated to date will be available for 1 magnet (not shared) Test of LHe containment in SQXF2b 2 nd generation coils LARP RRP: SQXF3 and SQXF3b (2016) CERN PIT: SQXF4 (2016-2017) CERN RRP: SQXF5 (2017) Test of 2-magnets in 1-cold-mass: SQXF6 (2017) 5/11/2014 Paolo Ferracin43

44. CERN long models Schedule Coil winding starts in 09/2015 – 3 practice, 6 RRP, 6 PIT Mirror test in end 2016 / early 2017 First long model by mid-2017 2 long models, 4 tests in 2017-2018 5/11/2014 Paolo Ferracin44

45. Pre-series and series production (based on “Production Plan” from M. Anerella) CERN (Q2) full length 10 cold masses – 2 pre-series/spares, 8 series 10 magnets – 2 pre-series, 8 series 45 coils – 4.5 per magnet 80 days per coil 1 coil every 15 days LARP (Q1/Q3) half length 10 cold masses – 2 pre-series/spares, 8 series 10+10 magnets – 4 pre-series, 16 series 45+45 coils – 4.5 per magnet 80 days per coil 1 coil every 15 days 2 production lines 5/11/2014 Paolo Ferracin45

46. Pre-series and series production (based on “Production Plan” from M. Anerella) Tooling per production line (both CERN and LARP) – 1 oven – 1 vacuum impregnation tank – 2 winding mandrel assembly Winding while curing outer layer – 3 reaction tooling Preparation for reaction Reaction Preparation for impregnation – 2 impregnation tooling 5/11/2014 Paolo Ferracin46

47. Pre-series and series production (based on “Production Plan” from M. Anerella) CERN (Q2) Coil winding starts 09/2017 Coil fabric. ends by 02/2021 First magnet test in 04/2019 Last magnet test in 10/2021 LARP (Q1/Q3) Coil winding starts 03/2017 Coil fabric. ends by 08/2020 First magnet test in 11/2018 Last magnet test in 05/2021 5/11/2014 Paolo Ferracin47

48. Pre-series and series production CERN coil production 5/11/2014 Paolo Ferracin48

49. Pre-series and series production LARP coil production 5/11/2014 Paolo Ferracin49

50. Pre-series and series production Overview of magnet production 5/11/2014 Paolo Ferracin50