superconducting magnet program s. gourlay cern march 11-12, 2002 1 lawrence berkeley national...
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CERN March 11-12, 2002 Superconducting Magnet Program
1S. Gourlay
Lawrence Berkeley National Laboratory
IR Quad R&D Program
LHC IR Upgrade
Stephen A. Gourlay
CERN March 11-12, 2002 Superconducting Magnet Program
2S. Gourlay
LHC IR Quad Program
Goals and Deliverables
(Keeping in mind that there is very little money early in the program)
• Provide a quad design that meets requirements for an LHC IR upgrade– Determine requirements and identify issues
• Develop a technology base for future applications– Emphasize “Research” over “Development”
• Establish a true collaboration that is a model for the future– Leverage from existing programs
• What can participants provide?
• Train the next generation of magnet scientists– Not only developing new technology, but building resources as well
CERN March 11-12, 2002 Superconducting Magnet Program
3S. Gourlay
LHC IR Quad Program
Design Issues
• Field quality– Conductor placement– Magnetization
• Fabrication– Insulation thickness– Reaction dynamics (long coils)– Rad-hard epoxy
• Operational– Quench protection
• Push Limits• New Ideas
– Heat load• Energy extraction• Optimal operating temperature
Program Components
• Conductor and Cable Development
• Design– Magnetic– Mechanical
• Models– Drawings– Parts– Assembly
• Technology Development– Challenge existing biases
• Jcu
• RRR
CERN March 11-12, 2002 Superconducting Magnet Program
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Design Choices
• Cos(2)– Relatively complex (but familiar)
• Coupled forces• Assembly
– Efficient use of superconductor for large bore magnets
• Racetrack and Block– Relatively simple
• Force geometry• 2-D ends (Racetrack)• 3-D ends (Block)• Rectangular cable
– No degradation– No keystoning “issues”
CERN March 11-12, 2002 Superconducting Magnet Program
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Geom. harm. (r0 = 22 mm)(10-4 units)
b6 b10 b14
0.2 -0.8 0.04
Parameter Unit Inner OuterGss T/m 260Bpk T 12.7 10.8Iss kA 7.7 7.9L mH/m 24.4A(oct) mm2 624Riron mm 90
Four -layer Cos(2
Param. Unit Inner OuterStr. Diam. mm 0.8 0.65Nstrands 18 23Cab. Width mm 7.71 7.71Mid-thick mm 1.43 1.15Keystone deg 1.63 0.89Insulation mm 0.1 0.1Nt
(oct) 37 36Cu/Sc 1.0 1.5Jcu
ss kA/mm2 1.7 1.7
(Jc:2.0/4.2 - No degradation)
CERN March 11-12, 2002 Superconducting Magnet Program
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Cos(2)
• Two-Layer (a la FNAL)
• Four-Layer– Advantages
• Narrow cable – easier to wind, lower degradation• Fully-keystoned cross section – radial alignment• Possible to eliminate wedges – simpler end design• No inter-layer joint for grading• Better magnetic efficiency – mid-plane gap?• Low operating current• Higher gradient – potential for more
– Disadvantages• Tooling for inner and outer layers• Higher inductance – quench protection
CERN March 11-12, 2002 Superconducting Magnet Program
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Cos(2)
• Four-Layer options– Add a spacer if necessary– Add mid-plane gap and decrease bore– Increase strand and cable width – reduce number of turns and decrease
inductance
• Two-Layer options– Large keystone angle - Reduce Cabling degradation– More efficient cross section
CERN March 11-12, 2002 Superconducting Magnet Program
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Block-type Coils
Some attractive features . . .
• Potentially better control over conductor placement– Nb3Sn coils not as precise as NbTi?
• Rectangular conductor– No degradation, higher stability
• Separation of high field and high stress points– So far, no observation of stress degradation up to almost 15 Tesla in
dipoles
• Simplification of support structures and assembly techniques
• Some designs can be oriented to maximize “effective” aperture
CERN March 11-12, 2002 Superconducting Magnet Program
9S. Gourlay
Block-type Coils
“Nested” Racetrack
CERN BlockDesign
Racetrack Design
CERN March 11-12, 2002 Superconducting Magnet Program
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Conductor and Cable Development
• Conductor– RRR control and optimization– Reaction studies
• Optimization• Pre-anneal
• Cable– Cores
• Keystoned core for large keystone angles and low degradation• AC loss• Stabilizer
– Mixed-strand• Lower cost, tunability
– Compaction studies
CERN March 11-12, 2002 Superconducting Magnet Program
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LBNL Program Proposal
2003
• Conceptual Design– Work on optimization of coil designs – Evaluate the mechanical structure and coil support
• Fabrication and Test– Mechanical structure tests.– Using existing two-layer Nb3Sn coils, assemble and test a four-coil quad
configuration as a preliminary evaluation of the assembly, support scheme and training behavior of rectangular geometries.
• Program Supported Studies
CERN March 11-12, 2002 Superconducting Magnet Program
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LBNL Program Proposal
2004 – 2006
• Continue a program that evaluates “flat-coil” options– (Rate of 2 models per year)
2007 – 2008
• Construct Cos(2) design
• Compare with other options
CERN March 11-12, 2002 Superconducting Magnet Program
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Moving Forward
• Who are the participants?
– BNL, FNAL, LBNL
and
– CERN– CEA/Saclay– U. Twente– KEK– INFN
• What can they provide from existing programs?
• In order to make progress early we need to combine effort and use resources from base programs.
• Calls for a new model
CERN March 11-12, 2002 Superconducting Magnet Program
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Task Division
Task Lab A Lab B Lab CDesign A
Conductor and CableMagnetic DesignMechanical DesignAnalysisDrawingsParts FabAssemblyTest
Design BConductor and CableMagnetic DesignMechanical DesignAnalysisDrawingsParts FabAssemblyTest
Design CConductor and CableMagnetic DesignMechanical DesignAnalysisDrawingsParts FabAssemblyTest
Technology Studies
Institution
The “SSC” Way
CERN March 11-12, 2002 Superconducting Magnet Program
15S. Gourlay
Task Division
Task Lab A Lab B Lab CDesign A
Conductor and CableMagnetic DesignMechanical DesignAnalysisDrawingsParts FabAssemblyTest
Design BConductor and CableMagnetic DesignMechanical DesignAnalysisDrawingsParts FabAssemblyTest
Design CConductor and CableMagnetic DesignMechanical DesignAnalysisDrawingsParts FabAssemblyTest
Technology Studies
Institution
Cross-Integration
Division based on . . .
Resources
Program Contributions
ARP Support
Etc.
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