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

2. Outline Overview of MQXF design Strand and insulated cable
Coil design and magnetic analysis
Magnet parameters
Quench protection
Paolo Ferracin
5/11/2014

3. Overview of MQXF design
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
P. Ferracin
09/10/2014

4. Overview of MQXF design
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
Paolo Ferracin
5/11/2014

5. Overview of MQXF design
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
Paolo Ferracin
5/11/2014

6. From LARP HQ to MQXF HQ QXF Similar coil lay-out
4-blocks, 2-layer with same angle
Wider cable (from 15 to 18 mm), same stress with +30% forces
Same structure concept with additional accelerator features
Pre-load capabilities of HQ design qualified and successfully tested
Larger pole key for cooling holes, cooling channels, alignment – assembly - handling slots, LHe vessel HQ
QXF
Paolo Ferracin
16/10/2013

7. MQXF magnet design
Paolo Ferracin
5/11/2014

8. Outline Overview of MQXF design Strand and insulated cable
Coil design and magnetic analysis
Magnet parameters
Quench protection
Paolo Ferracin
5/11/2014

9. MQXF strand (from CERN technical specification document)
0.85 mm strand
Filament size <50 μm
OST 108/127: 57 μm
OST 132/169: 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)
OST RRP strand, 132/169
Bruker PIT strand, 192
Paolo Ferracin
5/11/2014

10. MQXF cable and insulation
Paolo Ferracin
5/11/2014

11. MQXF cable and insulation
40-strand cable
Thin - Mid - Thick thickness mm
tolerance: +/ mm
Width mm
tolerance: +/ mm
Keystone angle
0.55 deg.
tolerance: +/ deg.
Pitch length
109 mm
Assumed expansion during reaction
4.5% in thickness: ~70 μm, same keystone angle mm
2% in width: ~360 μm mm
SS core 12 mm wide and 25 μm thick
70 μm
360 μm
RRP cable
PIT cable
Paolo Ferracin
17/7/2013

12. Dimensional changes during heat treatment (Summary by H. Felice)
Unconfined cables
axial contraction: 0.1 to 0.3 %
thickness increase: 1.5 to 4 %
width increase: 1.5 to 2 %
LQ, TQ and HQ (first generat. Coils)
Thickness
LQ and TQ: 5.6 and 6% of increase
HQ: only 1 to 2 % of increase
In both cases, cable expanded in available space
Width
LQ, TQ, HQ => 1 to 2 % of increase
Values adopted in second set of HQ coils (clear signs of overcompressed coil)
Thickness: 4.5%; width: 2%
Note: values in a coil should be larger than for unconfined cable because of binder, which takes some space.
Measurements from D. Dietderich with MQXF cable
Thickness: 2.5-3%
Width: 1-1.5%
Keystone: increases by degrees
Ten stack measurements in progress at CERN and MQXF LARP coil 1 cross-section measurements at LBNL
Meas. performed at LBNL by J. Krishnan
Meas. Performed at FNAL D. Bocian, M. Bossert
width
Current assumption
4.5% in thickness
2% in width
Same keystone angle
Paolo Ferracin
5/11/2014

13. 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
Sample
Ins. Cable thickness (mm)
Bare cable thickness (mm)
Insulation thickness (mm)
001_1
1.822
1.530
146
001_2
1.823
1.531
001_3
1.821
101_1
1.817
143
101_3
1.816
102_1
145
102_2
1.819
144
102_3
Paolo Ferracin
5/11/2014

14. Assumptions for coil and tooling design
Cable dimension after reaction and 150 μm thick insulation
Coil cured in larger cavity
Pressure < 5MPa
Coil closed in reaction fixture in larger cavity
Coil after reaction and during impregnation in nominal cavity
Theoretical pressure ~5 MPa
Paolo Ferracin
5/11/2014

15. MQXF project schedule
Short model program: 5 CERN-LARP models,
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,
Coil fabrication starts in 2015: 01 (LARP), 10 (CERN)
First magnet test in 08/2016 (LARP) and 07/2017 (CERN)
Series production: 10 (CERN) + 10 (LARP) cold masses,
Coil fabrication starts in 01/2018
First magnet test in 10/2018
Paolo Ferracin
5/11/2014

16. Impact of cable dimensions optimization MQXF current schedule
2014
2015
2016
2017
2018
RRP short model 1
PIT short model 1
RRP short model 2
RRP long model 1
PIT long model 1
Paolo Ferracin
5/11/2014

17. Impact of cable dimensions optimization
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
Change of tooling
Unlikely, since radial shims added to accommodate cable width +/ mm
Still, curing shells to be redesigned and procured (~5 months)
22+28 = 50 turns
Paolo Ferracin
5/11/2014

18. Impact of cable dimensions optimization
Change of cable thickness, with same keystone angle
“Transparent” if absorbed by
Insulation
from 150 to 145 μm  10 μm
Cable expansion during reaction
From 4.5 % to 4%  ~10 μm
Change of cable thickness and/or keystone angle
Example: from 0.55 to 0.4 deg., with same mid-thickness
Thin edge from to mm  25 μm
Considering 28 turn  700 μm on the outer layer
22+28 = 50 turns
Paolo Ferracin
5/11/2014

19. Outline Overview of MQXF design Strand and insulated cable
Coil design and magnetic analysis
Magnet parameters
Quench protection
Paolo Ferracin
5/11/2014

20. 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: = 50 turns
All harmonics below 1 units at Rref = 50 mm
6 blocks in the ends
Iron pad removed with reduced length
1% peak field margin in the end
Paolo Ferracin
5/11/2014

21. Magnetization measurement of QXF strands X. Wang, D. R. Dietderich, A
Magnetization measurement of QXF strands X. Wang, D. R. Dietderich, A. Ghosh, A. Godeke, G. Sabbi
132/169 round wire and 108/127 extracted strand samples provided by BNL
Ti-Ternary, reduced-Sn
108/127 XS
132/169 RW
dwire before HT mm
0.85
Cu/non-Cu ratio -
1.17
1.19
dsub (geometric) μm 57 51
Jc(non-Cu, 4.2 K, 11 T)
A/mm2
3273
3317
Measurements performed by Mike Sumption and Xingchen Xu at OSU
Commercial Physical Property Measurement System
1.9 K
Field perpendicular to the sample length
4/30/2014

22. Magnetization comparison
Similar Jc(B) for both samples (difference within 1.5% between 10 T and 11.5 T)
Magnetization scales with sub-element diameter
As measured
108/127 Scaled by 89% (51/57)
4/30/2014

23. Persistent-current effect in QXF
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
ΔTF with ± 10% magnetization change
I (A)
100%
-10%
+10%
1000 1
0.02%
-0.01%
1500
0.07%
-0.07%
17500
0.00%
4/30/2014

24. b6 and b10 b6 b10 Geometric and saturation effect removed
±10% magnetization translates to ±12% of b6 and b10 at low field, ±10% at nominal field but negligible (tighter tolerance for low field?) b6
b10
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
I (A)
100%
-10%
+10%
1000
3.4
3.0
3.8
1500
2.4
2.2
2.6
17500
-0.02
4/30/2014

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

26. Coil design and magnetic analysis Magnet lengths
Short model
Q1/Q3 (half unit) Q2
Magnetic length [mm] at 293 K
1198
4012
6820.5
1194.4
4000
6800
“Good” field quality [m]
0.5
3.3
6.1
Coil physical length [mm] at 293 K
1510
4324
7132.5
Iron pad length [mm] at 293 K
975
3789
6597.5
Yoke length [mm] at 293 K
1550
4364
7172.5
Longitudinal thermal contraction = 3 mm/m (as LHC magnets)
Paolo Ferracin
5/11/2014

27. Coil design and magnetic analysis Conductor quantities
Short model
Q1/Q3 (half unit) Q2
Cable length per coil [m] (Roxie)
126
407
687
Cable length per coil [m] (with margin)
150
430
710
Strand per coil [km] (with margin)
6.3
18.1
30.0
Strand per coil [kg] (with margin) 32 91
Strand length = cable length * 40 * 1.05
1 km of 0.85 mm strand: 5 Kg.
Paolo Ferracin
5/11/2014

28. Outline Overview of MQXF design Strand and insulated cable
Coil design and magnetic analysis
Magnet parameters
Quench protection
Paolo Ferracin
5/11/2014

29. Superconductor properties Virgin strand, no self field correction
4.2 K
12 T: 2450 A/mm2, 632 A
15 T: 1400 A/mm2, 361 A
1.9 K
12 T: 3270 A/mm2, 844 A
15 T: 2043 A/mm2, 527 A
Paolo Ferracin
5/11/2014

30. Magnet parameters Self field corr. (ITER barrel)
0.429 T/kA
5% cabling degradation
Godeke’s parameterization
Operational grad.: 140 T/m
Iop: 17.5 kA
Bpeak_op: 12.1 T
80-81% of Iss at 1.9 K
Gss: 171 T/m
Iss: 21.6 kA
Bpeak_ss: 14.7 T
Stored energy: 1.3 MJ/m
Inductance: 8.2 mH/m
Ca1*
41.24 T
Ca2* = 1034 x Ca1*
42642
eps_0,a
0.250%
Bc2m*(0)
31.50
Tcm*
15.34 K C*
1541 TA p
0.5 q 2
Strain=
-0.20%
Paolo Ferracin
5/11/2014

31. Magnet parameters
Paolo Ferracin
5/11/2014

32. Mechanical analysis (by M. Juchno)
Optimization of dimensions and locations of new features
≥2 MPa of contact pressure at up to 155 T/m (~90% of Iss)
Peak coil stress: -160/-175 MPa
Coil displ. from start to nominal grad.
Radial/azimuth.: -0.3/-0.04 mm
Effect on field quality: 0.75 units of b6
Inner layer
Outer layer
Paolo Ferracin
5/11/2014

33. Outline Overview of MQXF design Strand and insulated cable
Coil design and magnetic analysis
Magnet parameters
Quench protection
Paolo Ferracin
5/11/2014

34. Quench protection (by V. Marinozzi)
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/Ncu: 1.13
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)
Paolo Ferracin
5/11/2014

35. Quench protection (by V. Marinozzi)
The MQXF hot spot temperature resulting from the QLASA simulation made with the assumption above is ~268 K, which can be considered enough far from the safe limit of 350 K. The protection study could be improved considering the quench back.
Paolo Ferracin
5/11/2014

36. Appendix
Paolo Ferracin
5/11/2014

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

38. Sub-element size as a function of stack

39. Persistent current harmonics in QXFTF b6
b10
b14
b18
T/m/kA
Unit at Rref = 50 mm
108/127
-19.3
4.9
-0.8
0.0
144/169
-16.4
4.2
-0.7
90%
85%
86%
187%
-32.3
3.7
-0.0
-27.7
3.2
87%
-1.3
-1.1
Second up-ramp data
1 kA, ~ injection
1.5 kA, negative peak
17.3 kA, nominal level
X. Wang
Given the same Jc, harmonics due to magnetization reduce by ~ 14%, consistent with the sub-element size reduction

40. Margin
Paolo Ferracin
5/11/2014

41. 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 ( )
All the coil fabricated to date will be available for 1 magnet (not shared)
Test of LHe containment in SQXF2b
2nd generation coils
LARP RRP: SQXF3 and SQXF3b (2016)
CERN PIT: SQXF4 ( )
CERN RRP: SQXF5 (2017)
Test of 2-magnets in 1-cold-mass: SQXF6 (2017)
Paolo Ferracin
16/10/2013

42. 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
Paolo Ferracin
16/10/2013

43. G. Ambrosio and P. Ferracin
Pre-series and series production (based on “Production Plan” from M. Anerella)
CERN (Q2) full length
LARP (Q1/Q3) half 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
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
G. Ambrosio and P. Ferracin
13/11/2013

44. G. Ambrosio and P. Ferracin
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
G. Ambrosio and P. Ferracin
13/11/2013

45. G. Ambrosio and P. Ferracin
Pre-series and series production (based on “Production Plan” from M. Anerella)
CERN (Q2)
LARP (Q1/Q3)
Coil winding starts 09/2017
Coil fabric. ends by 02/2021
First magnet test in 04/2019
Last magnet test in 10/2021
Coil winding starts 03/2017
Coil fabric. ends by 08/2020
First magnet test in 11/2018
Last magnet test in 05/2021
G. Ambrosio and P. Ferracin
13/11/2013

46. Pre-series and series production CERN coil production
G. Ambrosio and P. Ferracin
13/11/2013

47. Pre-series and series production LARP coil production
G. Ambrosio and P. Ferracin
13/11/2013

48. Pre-series and series production Overview of magnet production
G. Ambrosio and P. Ferracin
13/11/2013