glyn kirby
Post on 24-Feb-2016
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Glyn KirbyMagnet AssemblyTechniques
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)
History of Accelerator MagnetsLHC 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 todayKEK 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.
CERN-Oxford Inst.
(LHC development IR)
Fermi lab USA. (MQXB LHC IR)
KEK JP.(MQXA LHC IR)
3
LHC Upgrade Models
MQXC 120 mm / 120 T/m Nb-Ti MQXF 150 mm / 140 T/m Nb3Sn Force 2.8 X MQXC
Extraction the steady state heatUsing one Heat
Exchanger
Large program to study heat extraction through the magnet coils and structure.
Quench limit for NbTi SF 3 4.3mW/cm^3 ?
2% open yoke
6.6% open collar
6
Magnet Assembly Overview
Vertical assembly 9m magnet will need horizontal assembly
Large movements during compressing coil, insulation and collars 2 to 3 cm on dia.
Full length collaring keys
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Collaring
Design Collar / Coil Stress
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Collar Initial value Maximum value the beginning of the relaxation
Finish value
2_3 0.7 Mpa -145.4 MPa -77.3 Mpa -76.7 MPa4_3 -0.2 Mpa -141.8 Mpa -73.1 Mpa -68.8 Mpa
Coil stress measurement during collaring.
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Collapsible Mandrel Extraction
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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 coilsInsulation between all circuits.Quench heater firing at full 850V, 80A
Nb3Sn
Nb3Sn development historyTQ vs. LQ vs. HQ vs. QXF
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TQS1 m long500 mm
2006
LQS3.7 m long500 mm
2009
HQ1 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 withdispl. scaling = 20
#17
Principles of operation Key insertion and bladder deflation
Deform. shape withdispl. scaling = 20
#18
Principles of operation Cool-down
Deform. shape withdispl. scaling = 20
#19
Principles of operation Excitation
Deform. shape withdispl. scaling = 20
#20
Nb-Ti v Nb3Sn comparisonAssembly, Cool-down, and excitation
Nb3Sn low stress during assembly, pressure increases during cool down Loos pressure during powering
shell
CoilCoil
Nb-Ti High pressure at assembly the gradually looses pressure during cooling and powering
Assembly & Insertion of yoke stacks in shell
Outer yoke segments pre-assembled in packs.
4 Outer yoke segments loaded into Aluminum shell.
21
Assembly of Dummy Coil Pack
• Dummy Pack used to preload outer yoke segments.
• Short blocks screwed together.
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Insertion of dummy coil pack in shell-yokesub-assembly and bladder operation
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Assembly of 1.7 m long structure Preparation of alignment pins and bushings
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Assembly of 1.7 m long structure Joining operation of 2 segments (II)
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Assembly of 1.7 m long dummy coil pack
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Assembly of full-length structure3.2 m long coil-pack sub-assembly
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Loading of full-length structureBladder operation
28
Coil pre-loaded
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3.4m Magnet Manipulation
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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.
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 !
Nb3SnNb-Ti
Special thank you to Paolo Ferracin for providing the the B&K slides
The End
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