1. Glyn Kirby
Magnet AssemblyTechniques

2. Overview History of Accelerator Magnets Assemblies LHC IR Quadrupoles.
LHC Hi-Lumi Upgrade Models
MQXC Nb-Ti model triplet assembly
(back up design)
Nb3-Sn development history.
MQXF assembly procedure (base line design)

3. History of Accelerator Magnets LHC IR Quadrupole
Oxford Inst. used a thin spacer, coil was compressed with an aluminum ring, closed gap at cold no movement. Later converted to a 2-in-1 MQY and is in LHC today
KEK compressed the coil with a Yoke collar and large magnetic keys.
Fermi Lab used a collar to support the coil forced with a little help from the yoke.
KEK JP. (MQXA LHC IR)
Fermi lab USA. (MQXB LHC IR)
CERN-Oxford Inst.
(LHC development IR)

4. MQXF 150 mm / 140 T/m Nb3Sn Force 2.8 X MQXC
LHC Upgrade Models
MQXC 120 mm / 120 T/m Nb-Ti
MQXF 150 mm / 140 T/m Nb3Sn Force 2.8 X MQXC

5. Extraction the steady state heat
Using one Heat Exchanger
Quench limit for NbTi SF 3 4.3mW/cm^3 ?
6.6% open collar
2% open yoke
Large program to study heat extraction through the magnet coils and structure.

6. Magnet Assembly Overview
Large movements during compressing coil, insulation and collars 2 to 3 cm on dia.
Vertical assembly 9m magnet will need horizontal assembly
Full length collaring keys

7. Collaring

8. Design Collar / Coil Stress

9. Coil stress measurement during collaring.
Initial value
Maximum value
the beginning of the relaxation
Finish value
2_3
0.7 Mpa
MPa
-77.3 Mpa
-76.7 MPa
4_3
-0.2 Mpa
Mpa
-73.1 Mpa
-68.8 Mpa

10. Collapsible Mandrel Extraction

11. End Flange and Joint Box
End flanges welded to collaring keys
Multi layer joint box

12. 4 – 80mm diameter rods temporary replacement for outer shell
Yoke packing factor too high at 99.6% we need to reduce to 98% for the next magnet .

13. Electrical Checks (very important)
We performed electrical checks at each stage of production
1KV pulse test looking for shorts in the coils.
5KV ground insulation tests.
Resistance and inductance of coils
Insulation between all circuits.
Quench heater firing at full 850V, 80A

14. Nb3Sn

15. Nb3Sn development history TQ vs. LQ vs. HQ vs. QXF
TQS
1 m long
500 mm 
2006
LQS
3.7 m long
500 mm 
2009 HQ
1 m long
570 mm 
2010
QXF
~1.5 m
630 mm 
2015 (exp.)
Substantial development with this type of structure.

16. Principles of operation Bladder pressurization
Deform. shape with
displ. scaling = 20

17. Principles of operation Key insertion and bladder deflation
Deform. shape with
displ. scaling = 20

18. Principles of operation Cool-down
Deform. shape with
displ. scaling = 20

19. Principles of operation Excitation
Deform. shape with
displ. scaling = 20

20. Nb-Ti v Nb3Sn comparison Assembly, Cool-down, and excitation
Nb-Ti High pressure at assembly the gradually looses pressure during cooling and powering
shell
Nb3Sn low stress during assembly, pressure increases during cool down Loos pressure during powering
Coil
Coil

21. Assembly & Insertion of yoke stacks in shell
Outer yoke segments pre-assembled in packs. 4 Outer yoke segments loaded into Aluminum shell.

22. Assembly of Dummy Coil Pack
Dummy Pack used to preload outer yoke segments.
Short blocks screwed together.

23. Insertion of dummy coil pack in shell-yoke sub-assembly and bladder operation

24. Assembly of 1.7 m long structure Preparation of alignment pins and bushings

25. Assembly of 1.7 m long structure Joining operation of 2 segments (II)

26. Assembly of 1.7 m long dummy coil pack

27. Assembly of full-length structure 3.2 m long coil-pack sub-assembly

28. Loading of full-length structure Bladder operation

29. Coil pre-loaded

30. 3.4m Magnet Manipulation

31. Summary for Assembly Techniques
For the main IR Quad, needed for the LHC Hi-Luminosity upgrade, CERN with the help of the US labs, are developing a Nb3Sn magnet, with the bladder & key structure.
As a backup a high heat extraction Nb-Ti model magnet was successfully tested. The techniques used in this assembly can be applied to the other Nb-Ti magnet that are needed for the upgrade e.g. D1, D2, MQY, and zoo of Correctors.

32. Thanks to the teams.
Many people have worked on the Nb-Ti MQXC. And Nb3Sn bladder & key
designs. Hear we see a few. Thanks to you all !
Special thank you to
Paolo Ferracin for providing the the B&K slides
Nb-Ti
Nb3Sn

33. The End