1. 1st FNAL-CERN Collaboration Meeting Fermilab, May 13, 2011
Strand and Cable R&D
D. Turrioni, Fermilab
1st FNAL-CERN Collaboration Meeting Fermilab, May 13, 2011

2. Outline Cable and Strand Specifications
Cabling machine, tooling and instrumentation
Cable study and development
QA/QC
Summary
13 May 2011, FNAL-CERN CM1
Strand and Cable

3. Cable Specification
Parameter
Value
Cable Cross Section
Un-reacted
Reacted
Cable unit length, m
210
Rectangular
Keystoned
Number of strands 40
Transposition angle, degree 15
Transposition direction
Left-hand screw
Mid-thickness, mm
1.269
1.307
Thin edge, mm
1.167
1.202
Thick edge, mm
1.370
1.411
Width, mm
14.70
14.847
Key-stone angle, degree
0.79
0.81
Insulation thickness, mm
0.150
0.100
The large aspect ratio of the cable and the present cabling procedure require the cable fabrication in two stages: the rectangular cable with narrower width and lower packing factor and the keystone cable with final parameters
Long Unit Length ~ 210 m
13 May 2011, FNAL-CERN CM1
Strand and Cable

4. Strand Specification
Nb3Sn RRP-108/127 strand produced by Oxford SC Technology
Relatively Stable 4.5 K and 1.9 K
High Jc
13 May 2011, FNAL-CERN CM1
Strand and Cable

5. Cabling Machine Respooler Compact machine. Two major upgrades :
Continuous cable pitch regulation with the electronic synchronization of the main wheel and the caterpillar motion
42-spool wheel
Max Speed of 5 m/min
Respooler
13 May 2011, FNAL-CERN CM1
Strand and Cable

6. Cable Forming Fixtures
Turk head
Keystoning
Tooling
Side Rollers and Mandrels
13 May 2011, FNAL-CERN CM1
Strand and Cable

7. Instrumentation
Mitutoyo Digimatic Multiplexer MUX-10
Turk head Mitutoyo Dial Indicator ( 1 µm resolution )
Keystoning tooling Dial Indicator ( 1 µm resolution )
Mitutoyo Micrometer ( 1 µm resolution ) PC
Measurements of the two dial indicators are acquired every 3 cm at 1 m/min of production speed.
13 May 2011, FNAL-CERN CM1
Strand and Cable

8. 40 Strands cable for practice coil
Cable Measurements
40 Strands cable for practice coil
13 May 2011, FNAL-CERN CM1
Strand and Cable

9. Cable development
Design and parametric considerations were used in the development of the cables to be made of Nb3Sn RRP wires.
For the cable geometry contemplated by the magnet designers the mandrel was designed in order to provide sufficient room for the strands to wind around it without excessive damage.
This requirement, which accompanied the requisites for mechanical stability, allowed determining quite accurately the number of strands needed for each cable geometry.
13 May 2011, FNAL-CERN CM1
Strand and Cable

10. Cable Design Parameters
The geometrical relationship between a cable of desired width wC, to be obtained with strands of diameter d, and the required mandrel width wm is shown in the first expression below where  is an empirical factor determined by experiment.
The second expression is a simplified formula used for the purpose of parameterizing the number of strands needed for each cable geometry. N is the number of strands in the cable,  the cable lay (or pitch) angle
A large body of data acquired during Nb3Sn conductor development shows that when cabling Nb3Sn RRP wires, it is important that:
 ≥ 1
TD “Nb3Sn Cable Development for the 11 T Dipole Program”
13 May 2011, FNAL-CERN CM1
Strand and Cable

11. 40 Strands Cables List Next slides show results of:
Cable Traveler Name
Type
Length, m
Strand design
No. strands
Strand size, mm
Mandrel width, mm
Lay angle, degree
PF, %
SS Core
R&DT_101007_40_1_0 R 50 Cu 40
0.697
13.93 15
83.4 N
R&DT_101026_41_1_0 41
14.24
15.5
84.0 “
R&DT_101101_40_1_1a
13.95
83.8 Yb
R&DT_101101_40_1_1b
17.5
85.1
R&DT_101109_40_1_0 10
RRP108
0.703
82.8
R&DT_101109_40_1_1
83.7
R&DT_110103_40_1_0
325
0.699
13.63
R&DT_110315_40_1_0 K
230
RRP114
13.92
86.3 Ka
85.8
R&DT_110420_40_1_0
190
a Rectangular cable has been annealed in Argon at 180 Cº for 1 hr
b Stainless steel core used was mm x 25 mm in size.
Next slides show results of:
Five Rectangular copper practice cables with and without core
Two rectangular Nb3Sn practice cable with and without core (108/127 strand design)
One Keystoned Nb3Sn practice cable without core (114/127 strand design)
13 May 2011, FNAL-CERN CM1
Strand and Cable

12. Cable development Rectangular Copper Cables
The first forming step of the rectangular cables to be used to produce keystoned cables 14.7 mm (with 40 strands) and 15.1 mm (with 41 strands) wide was finalized out of hard Cu wires of 0.7 mm nominal diameter.
The rectangular cables were 1% narrower than the final desired widths of the keystoned cables in order to account for the 1% width expansion to be expected when performing the second, keystoning, cabling step.
Selected design was the 40 strand cable because of CERN cabling machine capability
Cable Traveler Name
Length, m
No. strands
Strand size, mm
Mandrel width, mm
Lay angle, degree
PF, %
SS Core
R&DT_101007_40_1_0 50 40
0.697
13.93 15
83.4 N
R&DT_101026_41_1_0 41
14.24
15.5
84.0 “
R&DT_101101_40_1_1a
13.95
83.8 Ya
R&DT_101101_40_1_1b
17.5
85.1
a Stainless steel core used was mm x 25 mm in size.
13 May 2011, FNAL-CERN CM1
Strand and Cable

13. Cable development Rectangular Nb3Sn
To verify the impact of the cabling process on the actual superconductor that will be used in the magnet short model two 40 strands superconducting cables were produced.
Strand design RRP 108/127, 0.7 mm
The appropriate electrical and microstructural characterizations were done
Cable Traveler Name
Length, m
Lay angle, degree
PF, %
SS Core
Cable width ±σ, mm
Cable thickness ±σ, mm
R&DT_101109_40_1_1
6.71 15
83.7 Ya
14.61±0.02
1.331±0.003
R&DT_101112_40_1_0
7.5
82.8 N
14.62±0.02
1.328±0.003
a Stainless steel core used was mm x 25 mm in size.
13 May 2011, FNAL-CERN CM1
Strand and Cable

14. No. cross sections analyzed Min./Max. Merged subelements
Damage Analysis
Cable name
RRP Strands used
No. cross sections analyzed
Strands w/Damage
Broken subelements
Min./Max. Merged subelements
Damaged subelements
R&DT_101109_40_1_1 (w/core)
108/127 6 1 2
0/2
R&DT_101112_40_1_0 (no core)
Cable cross section with core
6 cross sections of each cable (with and without core) are studied.
Both cables show very little internal damage.
These cables show less than average strand damage.
Damage Details
13 May 2011, FNAL-CERN CM1
Strand and Cable

15. Electrical characterization Rectangular with core
In VI Tests, solid markers stands for Iquench evaluated from full transition, whereas empty markers stands for the maximum current reached by sample before quench with no visible transition.
Ic,
Ic , T
Is 0-4T
Is 4-8T
RRR
Extracted Cored cable #1
288,1626
468,2643
950
575
Extracted Cored cable #2
248,1400
424,2400
925
975
182
Round
275,1553
455 ,2570
1175
775
13 May 2011, FNAL-CERN CM1
Strand and Cable

16. Electrical characterization Rectangular without core
In VI Tests, solid markers stands for Iquench evaluated from full transition, whereas empty markers stands for the maximum current reached by sample before quench with no visible transition. Ic
Is 0-4T
Is 4-8T
RRR
Extracted UnCored cable #1
282,1593
464 ,2620
1225
800
Extracted UnCored cable #2
262,1479
414 (Imax)
1200
725
232
Round
275,1553
455,2570
1175
775
13 May 2011, FNAL-CERN CM1
Strand and Cable

17. Keystoned cables
After the first stage of rectangular cable study was completed and the new rollers for the keystoning fixture commissioned the second stage was to make keystoned cables.
The attempt to make in a single pass a keystoned copper cable was not completely successful. The cable formed but roped entering the keystone wheels in the first 80m.
The decision was to finish the remaining 245m rectangular and to make a second rectangular copper cable to be wound in a practice coil.
13 May 2011, FNAL-CERN CM1
Strand and Cable

18. Rectangular Copper Practice Cable #2
Cable Traveler Name
No. strands
Strand size, mm
Mandrel width, mm
Cable width, mm
Cable thickness, mm
Lay angle, degree
PF, %
SS Core
Length, m
R&DT_110301_40_1_0 40
0.696
14.05
14.76
1.237 15
86.2 N
250
Cable was fabricated for winding a practice coil.
Cable was well formed and to size
Left Side view
Right Side view
Top view
13 May 2011, FNAL-CERN CM1
Strand and Cable

19. Keystoned Nb3Sn cable RRP 114/127
Nb3Sn Keystoned 40 strands cable was made in two passes.
114/127 Strand design
The cable strands diameter except one was originally 1 mm drawn to 0.7 mm.
In the first pass 250 m of rectangular cable was made.
A piece of 15 m of the rectangular cable was cut and annealed in argon atmosphere for 1 hour at 180 ºC.
The two cables , annealed and not, were keystoned.
Microstructural analysis of cable cross sections and electrical characterization of extracted samples were performed.
Keystoned no annealed
RRP 114/127
Keystoned annealed
Cable Traveler Name
Type
Length, m
Mandrel width, mm
Lay angle, °
PF, %
Cable width±σ, mm
Cable thickness±σ, mm
R&DT_110315_40_1_0 R
248.4
13.92 15
84.04
14.556±0.038
1.316±0.009 Ra
84.1
14.599±0.039
1.309±0.005 K
230 -
86.3
14.71±0.012
1.265±0.005 Ka
85.8
14.69±0.02
1.274±0.005
a Rectangular cable has been annealed in Argon at 180 Cº for 1 hr
13 May 2011, FNAL-CERN CM1
Strand and Cable

20. Damage Analysis Nb3Sn KS Cable
Rectangular
Keystoned
Rectangular
Reacted
Keystoned
reacted
Keystoned Annealed
Reacted
Several cross sections from keystoned, rectangular, keystoned annealed, reacted and unreacted cable were analyzed.
Rectangular cable edges
13 May 2011, FNAL-CERN CM1
Strand and Cable

21. Damage Analysis Nb3Sn KS Cable (cont’d)
Cable Traveler Name
Type
Reacted
No. CS
No of Strands w/ possible damage
Total No. broken subelements
Min/Max. No. merged subelements
No. Damaged Subelements
R&DT_110315_40_1_0 R N 6
0/0 K 4 15
5/5 Y 1 2 13
14/14 16 Ka 3
0/2
a Rectangular cable has been annealed in Argon at 180 Cº for 1 hr
6 cross sections of each Type (Rectangular, Keystoned, Keystoned annealed) are studied.
Keystoned cable shows an average strand damage.
The annealed cable shows less than average strand damage.
13 May 2011, FNAL-CERN CM1
Strand and Cable

22. Electrical characterization Nb3Sn KS Cable
Ic 14 T
Ic 12 T
Is 0-4T
Is 4-8T
RRR
Keystoned A #1 HT269
266, 1382
442, 2297
925
750
150
Keystoned A #2 HT269
268, 1393
447, 2323
1300
825
280
KS Ann A #1 HT270
302, 1569
482, 2505
950
>900
230
KS Ann A #2 HT270
307, 1595
489, 2541
196
Rect A #1 HT270
306, 1592
493, 2564
Round A HT 269
260, 1351
440, 2287
Round A HT 270
267, 1388
451, 2344
1475
1000
300
In VI Tests, solid markers stands for Iquench evaluated from full transition, whereas empty markers stands for the maximum current reached by sample before quench with no visible transition
13 May 2011, FNAL-CERN CM1
Strand and Cable

23. Cable Readiness Review
An internal readiness review of the 11 Tesla dipole cable was held on May 02, 2011.
The following aspects were reviewed:
Procedure
Documentation (Traveler, Logbooks)
Infrastructures (Cable Machine, Tooling)
Overall their were no major or minor findings
Starting cable fabrication for the demonstrator coils
Front page of the cable traveler
13 May 2011, FNAL-CERN CM1
Strand and Cable

24. Cable Map
OXFORD
RRP 108/127
BILLET #
SIZE
METERS
DATE REC.
0.7mm
636
Mar.23.11
554
952
443
359
1998
1012
2793
2411
722
3625
2273
713
469
2011
601
784
2456
TOTAL
24812
OXFORD
RRP 108/127
BILLET #
SIZE
METERS
DATE REC.
0.7mm
1871.5
Aug.31.10
1665 a
600 b
700 c
2776 d
567 a
1647
2140
410
2599
427
462
714
TOTAL
1 UL→ 210 m
3 UL for a long cable + 1 UL + 60 m for the analysis
Cable fabrication for 11T Demo Coils in progress
13 May 2011, FNAL-CERN CM1
Strand and Cable

25. Summary Cable has been designed
Technology developed and experiments verified
Reviewed
Cable Fabrication in progress
13 May 2011, FNAL-CERN CM1
Strand and Cable

26. R&D steps Fabrication and test of Cored Cables
Longer UL (650 m) for 5.5 m long coil
New Strand Design
RRP-151/169 from OST
R&D strand from Hyper Tech, Inc.
PIT strand from CERN
13 May 2011, FNAL-CERN CM1
Strand and Cable