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11 T Dipole EM Design & Quench Analysis. B. Auchmann & M. Karppinen CERN TE-MSC. Magnet Design Constraints. ∫ BdL = 119.2 Tm @ I nom = 11.85 kA 2-in-1 design, intra-beam distance 194 m Cold mass outer contour from MB Heat exchanger location as in MB - PowerPoint PPT Presentation
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11 T Dipole EM Design & Quench Analysis
B. Auchmann & M. Karppinen CERN TE-MSC
B. Auchmann & M. Karppinen CERN TE-MSC 2
Magnet Design Constraints
• ∫BdL = 119.2 Tm @ Inom = 11.85 kA• 2-in-1 design, intra-beam distance 194 m• Cold mass outer contour from MB• Heat exchanger location as in MB• Aperture: Sagitta: 11 m – 5.0 mm, 5.5 m – 1.3 mm
=> Ø60 mm aperture and straight cold mass • 20 % operation margin on the load-line at 1.9 K• Field harmonics at 10-4 level (TBC by AP)
13 May 2011, Collaboration Meeting
B. Auchmann & M. Karppinen CERN TE-MSC 3
11 T Model Program
13 May 2011, Collaboration Meeting
B. Auchmann & M. Karppinen CERN TE-MSC 4
Cable & Insulation
250 m Nb3Sn cable produced Jc measurements underway
First CERN cabling run expected Beg-May
13 May 2011, Collaboration Meeting
B. Auchmann & M. Karppinen CERN TE-MSC 5
Measured Jc of OST 108/127 RRP strand (40-strand rectangular cable)
Courtesy of E. Barzi, FNAL
13 May 2011, Collaboration Meeting
B. Auchmann & M. Karppinen CERN TE-MSC 6
2D-Models used for Coil Optimization
1-in-1 Yoke ID/OD 130/400 160/400 200/400 200/550 160/550
B0(T) 11.66 11.22 10.76 11.20 11.67
11.21 T 6-Block design, 56 Turns, no core
13 May 2011, Collaboration Meeting
B. Auchmann & M. Karppinen CERN TE-MSC 7
Possible Coil X-Sections
6 Blocks56 turns
7 Blocks56 turns
6 Block SS Core58 turns
6 Blocks SS Core55 turns
7 Block SS Core55 turns
13 May 2011, Collaboration Meeting
B. Auchmann & M. Karppinen CERN TE-MSC 8
Parameters of Coil X-Sections
13 May 2011, Collaboration Meeting
B. Auchmann & M. Karppinen CERN TE-MSC 9
2-in-1 & 1-in-1 Models
B0(11.85 kA) = 11.21 T
B0(11.85 kA) = 10.86 T
13 May 2011, Collaboration Meeting
B. Auchmann & M. Karppinen CERN TE-MSC 10
Iron Saturation
Relative permeability Induction (T)
Relative FQ (units)
13 May 2011, Collaboration Meeting
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B. Auchmann & M. Karppinen CERN TE-MSC 11
EM Forces
Total Fxaperture = 634 ton/m (MB = 428 ton/m)
13 May 2011, Collaboration Meeting
B. Auchmann & M. Karppinen CERN TE-MSC 12
Working point & MarginsMeasured JcOST 108/127Ø0.70 mm10% degr.
80.4%
Bpeak(T)
Tmarg(K)Margin(%)
13 May 2011, Collaboration Meeting
B. Auchmann & M. Karppinen CERN TE-MSC 13
End DesignUp-right End Minimum Strain End
• Based on FNAL experience• Smaller voids to fill on yz-plane• More hard-way strain during winding• 2 winding blocks on the outer layer ends
• Based on CERN experience• Larger voids to fill on yz-plane• Minimum hard-way strain during winding• 3 winding blocks on the outer layer ends
13 May 2011, Collaboration Meeting
B. Auchmann & M. Karppinen CERN TE-MSC 14
Cotronics Ceramic Putty used at CERN
13 May 2011, Collaboration Meeting
B. Auchmann & M. Karppinen CERN TE-MSC 15
Selective Laser Sintering End Spacers (Stainless steel)
13 May 2011, Collaboration Meeting
B. Auchmann & M. Karppinen CERN TE-MSC 16
Coil Ends & Practice Coil
First practice coil wound with rectangular Cu-cableand stailess steel SLS end spacers
First Nb3Sn (114/127) practice coil will be woundas of 9 May.
Different end spacer designs will be used in lead and return ends.
13 May 2011, Collaboration Meeting
B. Auchmann & M. Karppinen CERN TE-MSC 17
3D Models
Yoke cut-back determined such that the Bp is in the straight section
1-in-1 Demonstrator DipoleYoke covers the ends.=> Bp = +0.25 T
13 May 2011, Collaboration Meeting
B. Auchmann & M. Karppinen CERN TE-MSC 18
Design Parameters
Note: Cryostat, beam-screen, beam-pipe, (slight) permeability of collars not included13 May 2011, Collaboration Meeting
B. Auchmann & M. Karppinen CERN TE-MSC 19
MCBM 1.9 Tm @55 AMCBCM 2.8 Tm @100 AMCBYM 2.6 Tm @ 88 A
Transfer Function Correction
Below Inom 11 T Dipole is stronger than MB
13 May 2011, Collaboration Meeting
B. Auchmann & M. Karppinen CERN TE-MSC 20
C8 C9 C10 C11 C8
RB.A23
Total inductance:15.5 H (152x0.1H + 2x0.15H)Total resistance: 1mWOutput current: 13 kAOutput voltage: 190 V
Trim1
Trim2
Main Power Converter
0.1H
0.15H
Total inductance: 0.15 HTotal resistance: 1mWRB output current: ±0.6 kARB output voltage: ±10 V
TRIM Power Converters
(+)• Low current CL for the trim circuits• Size of Trim power converters
(-)• Protection of the magnets• Floating Trim PCs (>2 kV)• coupled circuits
New RB Circuit (Type 1)
Courtesy of H. Thiessen13 May 2011, Collaboration Meeting
B. Auchmann & M. Karppinen CERN TE-MSC 21
Nested Trim Circuit
11 T Dipole current needs to be reduced
13 May 2011, Collaboration Meeting
B. Auchmann & M. Karppinen CERN TE-MSC 22
Coil MagnetizationMB (NbTi) 11 T Dipole Nb3Sn
Mid-Plane Inner LayerMid-plane Outer layerInner Layer PoleOuter Layer Pole
>10 X
13 May 2011, Collaboration Meeting
B. Auchmann & M. Karppinen CERN TE-MSC 23
Persistent Current Effects
13 May 2011, Collaboration Meeting
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B. Auchmann & M. Karppinen CERN TE-MSC 24
Persistent Current Effects
13 May 2011, Collaboration Meeting
B. Auchmann & M. Karppinen CERN TE-MSC 25
Persistent Current Effects
13 May 2011, Collaboration Meeting
B. Auchmann & M. Karppinen CERN TE-MSC 2613 May 2011, Collaboration Meeting
B. Auchmann & M. Karppinen CERN TE-MSC 27
dynamic aperture for ...ideal Nb3Sn dipoles (red) full error table (green)
and for completeness: limits in DA for the phase 1 upgrade study (blue)
for the experts: the plot shows the minimum DA for the 60 error distribution seeds used in the tracking calculations.
Field Quality: Dynamic Aperture StudiesCollision optics, 7 TeV
dyn aperture luminosity optics, 7 TeV, minimum of 60 seeds
Courtesy of B. Holzer
13 May 2011, Collaboration Meeting
B. Auchmann & M. Karppinen CERN TE-MSC 28
dynamic aperture for Nb3Sn case: full error table, b3 = 98 units (red) b3 reduced to 50 units (green)b3 reduced to 25 units (violett)b3 = 0 and to compare with: present LHC injection
for the experts: unlike to the collision case: at injection the b3 of the Nb3Sn dipoles is the driving force to the limit in dynamic aperture.A scan in b3 values has been performed and shows that values up to b3 ≈ 20 units are ok. Alternative solution: strong local spool piece corrector
Field Quality: Dynamic Aperture StudiesInjection optics, 450 GeV, no spool piece correctors
dyn aperture injection optics, minimum of 60 seeds
Courtesy of B. Holzer
13 May 2011, Collaboration Meeting
B. Auchmann & M. Karppinen CERN TE-MSC 29
Quench Heaters
Parameter Value
Conductor cross-section (mm2) 15.4
Cu/Sc ratio 1.106
RRR 100
Iultim. (A) for 12 T 13250
Diff. Inductance @ Iultim. (mH) 9.13
Stored energy @ Iultim. (kJ) 969
Temperature margin (K) 4 – 12
13 May 2011, Collaboration Meeting
B. Auchmann & M. Karppinen CERN TE-MSC 30
Protection Studies 1/2
Protection studies in progress in both labs:
• The 1-in-1 Demonstrator can be protected with energy extraction system and heaters
• The heater design and powering electronics are subject of R&D.• The Demonstrator test is a good opportunity for extensive
protection studies:• Extraction and heater delays• Heater efficiency and required coverage• Quench propagation• Quench-back
13 May 2011, Collaboration Meeting
B. Auchmann & M. Karppinen CERN TE-MSC 31
Protection Studies 2/2
Enthalpy margin to quench (mJ/cm3)
Protection-heater experiments will provethe efficiency of the protection system.
Simulation shows heater delays between2 and 20 ms.
Impact of instabilities and cable eddy-currents?(cored vs. non-cored cable)
13 May 2011, Collaboration Meeting
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B. Auchmann & M. Karppinen CERN TE-MSC 32
Summary• The magnetic design of the 11 T Dipole magnet is based on magnet technology
proven by the HFM programs and LHC magnet production.• Magnet design parameters meet the requirements of the LHC Collimation phase II
upgrade.• The engineering design of the 2-in-1 demonstrator is in progress. It will be the first
accelerator quality 2-in-1 Nb3Sn magnet. • First optics studies:
– Orbit error due to the TF of the 11 T Dipole can be corrected by using a significant factor of corrector strength outside of DS. Trim PC would solve the problem.
– b3 @450 GeV can be tolerated up to ˜20 units, which seems achievable (passive shimming, B3 corrector..).
• 1-in-1 Demonstrator magnet will demonstrate the quench performance and operation margin up to the design field of 12 T and give valuable experimental data on the magnetization effects:– Measured magnetization effects will serve to validate the numerical models.– The 1-in-1 Demonstrator dipole can be protected with an external dump resistor. – The 1-in-1 Demonstrator will serve to validate the protection system based on heaters for the
accelerator application.
13 May 2011, Collaboration Meeting
B. Auchmann & M. Karppinen CERN TE-MSC 33
R&D Topics• End part design• Magnetization effects control• Fast power abort tests (quench-back)• Quench protection:– Quench analysis tools– Heater system design– Heater studies
13 May 2011, Collaboration Meeting