1. Mechanical stability and QXF coil winding
P. Ferracin, L. Oberli, S. Izquierdo Bermudez
MQXF Conductor Review
November 5-6, 2014
CERN

2. Outline Winding test set-up and results
Coil winding experience at CERN
Paolo Ferracin
5/11/2014

3. First test set-up GEOMETRY 2: GEOMETRY 3: GEOMETRY 1:
POLE INNER LAYER
GEOMETRY 2:
BIG SPACER INNER LAYER
GEOMETRY 3:
POLE OUTER LAYER
Paolo Ferracin
5/11/2014

4. Second test set-up
Paolo Ferracin
5/11/2014

5. Second test set-up Layer jump
Paolo Ferracin
5/11/2014

6. Third test set-up Inner layer, favourable Outer layer, unfavourable
Paolo Ferracin
5/11/2014

7. Exampled of unstable cable
Paolo Ferracin
5/11/2014

8. Winding test example (with tool)
Paolo Ferracin
5/11/2014

9. Winding test example (with tool)
Paolo Ferracin
5/11/2014

10. “Parameter space” Nominal Min. – Max. Mid-thickness Width
1.525 mm
tolerance: +/ mm
Width mm
tolerance: +/ mm
Keystone angle
0.55 deg.
tolerance: +/ deg.
Pitch length
109 mm
Min. – Max.
Mid-thickness mm
Width mm
Keystone angle
Rect deg.
Pitch length mm
Paolo Ferracin
5/11/2014

11. 45 winding tests performed
Paolo Ferracin
5/11/2014

12. 45 winding tests performed
Paolo Ferracin
5/11/2014

13. Winding test conclusions By P. Ferracin, L. Oberli, S
Winding test conclusions By P. Ferracin, L. Oberli, S. Izquierdo Bermudez
In general, all RRP and PIT cables are stable in the favorable direction
Cable wound clock-wise around the pole (inner layer condition)
In general, all RRP and PIT cables are unstable in the unfavorable direction
The few PIT which did not show unstable behavior were not reproducible
The cable behaviour was not improving by changing winding tension
We performed tests at different winding tension (25 kg, 45 kg, 60 kg), and the behaviour was similar
The core does not seem to play a role in the cable mechanical stability
We only wound one RRP sample without core, but “typical behaviour”.
In general, all RRP and PIT cables can be wound with the tool (CERN) and/or with the binder (FNAL)
In some cases it is required to use a thinner tool which better follows the cable during all the length of the turn
Paolo Ferracin
5/11/2014

14. Outline Winding test set-up and results
Coil winding experience at CERN
Paolo Ferracin
5/11/2014

15. Coil fabrication status: 3+3 coils wound and cured
LARP coil #1
completed
LARP coil #2
completed
LARP coil #3
Prep. For impregnation at BNL
CERN coil #001
Prep. For impregnation
CERN coil #101
Prep. For impregnation
CERN coil #102
Prep. For reaction
Paolo Ferracin
5/11/2014

16. Mandrel and pole set-up
Paolo Ferracin
5/11/2014

17. Mandrel and pole set-up
Paolo Ferracin
5/11/2014

18. Mandrel and pole set-up
Paolo Ferracin
5/11/2014

19. Inner layer winding Pole insulation
0.175 mm S2 glass, 33TEX, 493 sizing, 19 mm wide
Paolo Ferracin
5/11/2014

20. Inner layer winding Layer jump
Paolo Ferracin
5/11/2014

21. Inner layer winding Voltage taps
Paolo Ferracin
5/11/2014

22. Winding with tool
Paolo Ferracin
5/11/2014

23. Winding with tool
Paolo Ferracin
5/11/2014

24. Winding with tool
Paolo Ferracin
5/11/2014

25. Winding with tool
Paolo Ferracin
5/11/2014

26. Winding with tool
Paolo Ferracin
5/11/2014

27. Inner layer winding
Ceramic binder
Paolo Ferracin
5/11/2014

28. Ceramic binder during winding
CTD-1202X
From the technical specification
Curing 1 hour at 80°C + two hours at 150°C
We noticed that if we cure at T < 150°C, after 10 minutes the cable is still wet and the insulation is not rigid.
Paolo Ferracin
5/11/2014

29. Ceramic binder during winding
Procedure
Paint binder on the cable
Heat the cable on one side, and time 3 mins (after 3 mins, the cable temperature is ~150°C)
Heat the other side 3 mins.  
The cable is still wet and the insulation is not rigid. We cut the insulation and the fibers are not glued (very similar behaviour in the region with and without).
Paolo Ferracin
5/11/2014

30. Ceramic binder during winding
We repeated the process, heating up to 250°C, but the cable is still wet and the insulation is not rigid So
Coil 001: with ceramic binder
Coil 101 and 102: no ceramic binder
Paolo Ferracin
5/11/2014

31. End spacers
Paolo Ferracin
5/11/2014

32. Wedges
Paolo Ferracin
5/11/2014

33. End-shoes
Paolo Ferracin
5/11/2014

34. Ceramic binder for curing inner layer
Paolo Ferracin
5/11/2014

35. Curing inner layer
Paolo Ferracin
5/11/2014

36. Curing inner layer
Paolo Ferracin
5/11/2014

37. First Nb3Sn coil (101, low-grade RRP) Outer layer after curing
Paolo Ferracin
5/11/2014

38. First Nb3Sn coil (101, low-grade RRP) Outer layer after curing
Paolo Ferracin
5/11/2014

39. First Nb3Sn coil (101, low-grade RRP) Outer layer after curing
Paolo Ferracin
5/11/2014

40. Coil winding conclusions
The feed-back from the winding team about the stability of the insulated RRP cable during winding of coil 101 and 102 is extremely positive
No clear popped-out strands were observed, also by partially unwinding some of the turns
Similar conclusions come from LARP, which has wound 3 coils with RRP strand using the binder (and not tool)
From the winding team, it seems also clear that the braided insulation plays a key role in improving stability
However, it is not clear if, by simple visual inspection and touching the insulated cable during winding, a popped strand can be detected
CERN coil 101 (low grade RRP) and LARP coil 1 will be cut to check
Paolo Ferracin
5/11/2014

41. Appendix
Paolo Ferracin
5/11/2014

42. Winding with twist ~90 degrees in 150-200 mm, tightening the cable
Paolo Ferracin
5/11/2014

43. Winding with twist ~90 degrees in 150-200 mm, tightening the cable
Paolo Ferracin
5/11/2014

44. Winding with twist ~90 degrees in 150-200 mm, tightening the cable
Paolo Ferracin
5/11/2014

45. Winding with twist ~90 degrees in 150-200 mm, tightening the cable
Paolo Ferracin
5/11/2014

46. Winding with twist ~90 degrees in 150-200 mm, tightening the cable
Paolo Ferracin
5/11/2014

47. Winding with twist ~90 degrees in 150-200 mm, tightening the cable
Paolo Ferracin
5/11/2014