Superconducting Magnet Program S. Gourlay CERN March 11-12, Lawrence Berkeley National Laboratory IR Quad R&D Program LHC IR Upgrade Stephen A. Gourlay

Superconducting Magnet Program S. Gourlay CERN March 11-12, 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

Superconducting Magnet Program S. Gourlay CERN March 11-12, 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 J cu RRR

Superconducting Magnet Program S. Gourlay CERN March 11-12, 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”

Superconducting Magnet Program S. Gourlay CERN March 11-12, Geom. harm. (r 0 = 22 mm) (10 -4 units) Four -layer Cos(2  (Jc:2.0/4.2 - No degradation)

Superconducting Magnet Program S. Gourlay CERN March 11-12, 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

Superconducting Magnet Program S. Gourlay CERN March 11-12, 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

Superconducting Magnet Program S. Gourlay CERN March 11-12, Block-type Coils Some attractive features... Potentially better control over conductor placement –Nb 3 Sn 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

Superconducting Magnet Program S. Gourlay CERN March 11-12, Block-type Coils “Nested” Racetrack CERN Block Design Racetrack Design

Superconducting Magnet Program S. Gourlay CERN March 11-12, 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

Superconducting Magnet Program S. Gourlay CERN March 11-12, 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 Nb 3 Sn 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

Superconducting Magnet Program S. Gourlay CERN March 11-12, 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

Superconducting Magnet Program S. Gourlay CERN March 11-12, 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

Superconducting Magnet Program S. Gourlay CERN March 11-12, Task Division The “SSC” Way

Superconducting Magnet Program S. Gourlay CERN March 11-12, Task Division Cross-Integration Division based on... Resources Program Contributions ARP Support Etc.