1. 11 T Nb3Sn Demonstrator Dipole R&D Strategy and Status
Zlobin, Fermilab
1st FNAL-CERN Collaboration Meeting Fermilab, May 13, 2011

2. Outline 11 T Nb3Sn Dipole R&D Program
R&D phases, goals, design constraints
Comparison with other R&D programs
Single-aperture demonstrator R&D
Status
Schedule
Conclusions
13 May 2011, FNAL-CERN CM1
A. Zlobin - R&D Strategy

3. 11 T Nb3Sn Dipole R&D
In FY2011 Fermilab and CERN have started a joint R&D program with the goal of building a long twin-aperture Nb3Sn 11 T dipole by 2014.
This R&D relies on the results of Nb3Sn magnet R&D programs at FNAL and Nb-Ti LHC magnet development at CERN.
To meet the tight project schedule within the available budget, magnets are designed to make maximum use of the existing tooling, infrastructure, and magnet components at both laboratories.
Practical orientation is a key feature for any sound Nb3Sn accelerator magnet R&D program at the present time.
13 May 2011, FNAL-CERN CM1
A. Zlobin - R&D Strategy

4. Result Application LHC collimation system upgrade.
11 T 11-m long twin-aperture Nb3Sn dipoles compatible with the LHC lattice and major systems can provide the required space for cold collimators
additional design constrains
Space in the LHC lattice for different insertion devices
dynamic collimators, correctors, instrumentation, etc.
13 May 2011, FNAL-CERN CM1
A. Zlobin - R&D Strategy

5. R&D Phases and Goals
Productive CERN-FNAL collaboration is a key to success!
13 May 2011, FNAL-CERN CM1
A. Zlobin - R&D Strategy

6. Constraints
11+ T at the LHC nominal current and operation temperature, 20% margin, field quality, quench protection
Compatibility with MB cold mass and cryostat designs
aperture diameter and separation, cold mass OD, heat exchanger
Nominal field >11 T => Nb3Sn
20% operational margin at 1.9 K => Bmax=13.2 T
Common yoke and separate collared coils
collaring press capability limit at FNAL, lower risk
Magnet length ~11 m, coil length ~5.5 m
Tooling limitations at FNAL, shorter strand and cable length, lower scale up risk
11m Magnet
FNAL
CERN
5.5 m Dipole Cold Mass
13 May 2011, FNAL-CERN CM1
A. Zlobin - R&D Strategy

7. Single-bore Demonstrator
Challenges: aperture, length, Bmax, W, schedule
13 May 2011, FNAL-CERN CM1
A. Zlobin - R&D Strategy

8. Twin-bore Demonstrator
Challenges: 2-in-1 horizontal configuration, aperture, aperture separation, Bmax, length, schedule
13 May 2011, FNAL-CERN CM1
A. Zlobin - R&D Strategy

9. Scale Up Challenges LARP: 4-m long single-aperture quadrupole by 2014
Test in vertical dewar at VMTF (Fermilab) at K
11 T Dipole program:
5.5-m long single coil test in MQXB prototype cryostat in 2013 (Fermilab or CERN)
5.5-m long twin-aperture dipole by 2014
Assembly with LHC MB cryostat and test at CERN MTF at K
13 May 2011, FNAL-CERN CM1
A. Zlobin - R&D Strategy

10. 11 T R&D Impact Very interesting and challenging R&D program
Benefit generic SC accelerator magnet R&D
Nb3Sn practical application in HL-LHC
Step towards high-field magnets for HE-LHC
13 May 2011, FNAL-CERN CM1
A. Zlobin - R&D Strategy

11. Demonstrator R&D R&D status Details in the following talks
Strand and cable
Magnetic design and parameters
Mechanical design and analysis
Quench protection
Magnet design and infrastructure
Details in the following talks
13 May 2011, FNAL-CERN CM1
A. Zlobin - R&D Strategy

12. Strand and Cable Details by Daniele. Strand (OST): Cable (FNAL):
Table 1: Cable parameters
Strand and Cable
Strand (OST):
0.7 mm Nb3Sn RRP-108/127
high-Jc, relatively stable
Cable (FNAL):
15-mm wide, 40 strands
Cable insulation:
0.075-mm E-glass tape
2 layers butt lap
traditional insulation technique
Strand procurement
60 kg RRP-151/169 – R&D (Aug 2011)
152 kg RRP-108/127 (Dec 2011)
152 kg RRP-108/127 (Jul 2012)
Cable fabrication
Practice cable fabricated and tested
Cable for demonstrator in progress
Details by Daniele.
13 May 2011, FNAL-CERN CM1
A. Zlobin - R&D Strategy

13. Coil Design Details by Mikko and Fred. Design
2-layer 6-block design
60-mm aperture
Coil winding, curing, reaction and impregnation tooling designed and procured
Coil components designed and procured
Coil end parts were designed and fabricated by CERN
Coil fabrication
1st practice coil wound and cured
Rectangular copper cable
2nd practice coil winding started
RRP-114/127 keystone cable
Details by Mikko and Fred.
13 May 2011, FNAL-CERN CM1
A. Zlobin - R&D Strategy

14. Dipole Parameters Parameter Value Aperture [m] 60
Nominal current Inom [A]
11850
Nominal bore field [T]
10.86
Short-sample bore field at 1.9 K [T]
13.6
Margin Bmax/Bnom at 1.9 K [%]
25.4
Maximum design field [T]
12.0
Inductance at Inom [mH/m]
5.6
Stored energy at Inom [kJ/m]
473
Fx per quadrant at Inom [kN/m]
2889
Fy per quadrant at Inom [kN/m]
1570
Coil length [m]
1.8
Magnetic length [m]
1.69
13 May 2011, FNAL-CERN CM1
A. Zlobin - R&D Strategy

15. Mechanical Structure Design
25-mm thick slightly elliptical stainless steel collar
Vertically split iron yoke
Al clamps
12.7-mm stainless steel skin
50-mm thick end plates
Structure design and mechanical analysis complete
Maximum stress in coil <160 MPa
stresses in structure are within limits
Collar design complete and procurement started.
Assembly tooling design is in progress.
Details by Igor and Fred.
13 May 2011, FNAL-CERN CM1
A. Zlobin - R&D Strategy

16. Quench Protection
Demonstrator quench protection during test will be provided by extracting the stored magnetic energy on the appropriate external dump resistor.
In accelerator, the magnet protection is provided by quench heaters.
Quench protection heaters composed of stainless steel strips will be placed inside the ground insulation, covering the outer-layer coil blocks.
Quench protection analysis and heater design are in progress (Mikko).
13 May 2011, FNAL-CERN CM1
A. Zlobin - R&D Strategy

17. Schedule, Milestones, QA
Structure review
Coil review
Cable review
Winding review
DOE review
Demonstrator specs
Performance review
13 May 2011, FNAL-CERN CM1
A. Zlobin - R&D Strategy

18. Conclusions
11 T Nb3Sn demonstrator dipole magnets for possible use in accelerators in particular for the LHC upgrades are being developed by Fermilab/CERN collaboration.
The engineering design of the 60-mm single-aperture 2-m long magnet and fabrication tooling is nearly complete and practice coil winding is in progress.
The cold tests are planned towards the end of 2011
Primary goal: demonstrate the quench performance, nominal field, and operation margins
Auxiliary studies: field quality, magnet quench protection
The conceptual design of the twin-aperture 11 T dipole magnet has been started.
13 May 2011, FNAL-CERN CM1
A. Zlobin - R&D Strategy