Post on 01-Apr-2015
QXF Magnetization
VERY preliminary analysis
Susana Izquierdo Bermudez07/05/2013
2
QXF. Main Parameters
Susana Izquierdo Bermudez
• Napa Cross-Section
• Iron yoke updated (remove bus-bar slot)
6 7 8 9 10 11 12 13 14 15 160
500
1000
1500
2000
2500
Round wire Ic versus applied magentic field at 4.2 K
RW, Bapplied RW XS, Bapplied XS
Applied magnetic induction [T]
Criti
cal c
urre
nt [A
]
6.00 7.00 8.00 9.00 10.00 11.00 12.00 13.00 14.00 15.00 16.000
5001000150020002500300035004000
Wire Je versus applied magnetic field, Summers
4.2, aplied magnetic induction 1.9, aplied magnetic induction4.2, total magnetic induction 1.9, total magnetic induction
Magnetic induction [T]Wire
curr
ent d
ensit
y [A
/mm
^2]
• Jc fit
https://plone.uslarp.org/MagnetRD/DesignStudies/QX-CD/Magnetic/Study%20of%20the%20QXF%20cross-section/folder.2013-04-15.9119834501/
• 2650A/mm2 at 12T, 4.2K• 1400A/mm2 at 15T, 4.2K• Degradation: 5 %
3
QXF. Cable parameters
XF150HTA (ref. 1, nov 2012)
XF150HTA1 (ref. 2, march 2013)
XF150HTA2 (ref. 3, may 2013)
Bare Cable after reaction
Width (mm) 18.638 18.3 18.3Thickness in (mm) 1.459 1.454 1.454Thickness out (mm) 1.676 1.66 1.66
Other cable parameters
# strands 40 40 40transposition pitch (mm) -- 109 109Degradation (%) 5 5 5
Insulation thickness
Radial (mm) 0.15 0.125 0.125Azimuthal (mm) 0.15 0.125 0.125
Jc Summers fit
(sf no included)
Data2650A/mm2 at 12T, 4.2K1400A/mm2 at 15T, 4.2K
2650A/mm2 at 12T, 4.2K1400A/mm2 at 15T, 4.2K
2650A/mm2 at 12T, 4.2K1400A/mm2 at 15T, 4.2K
C 3.82E+10 3.82E+10 3.82E+10Bc20 28.075 28.075 28.075Tc0 18 18 18
FilamentName OST RRP 108/127 OST RRP 108/127 OST RRP 108/127Outer diameter (um) 50 50 56Inner diameter (um) 0 0 0
StrandDiameter (mm) 0.85 0.85 0.85Cu/SC 1.13 1.13 1.15RRR 150 150 150
Susana Izquierdo Bermudez
Parameters used for all the calculations shown in this presentation
WRONG!Reference?
4
Magnetization models implemented in ROXIE
• Scalar model
(nested ellipse model)
Identical to the scalar model, but takes into account that, in the case of an applied rotating field, the orientation of the magnetization that is produced by a filament de-couples from the direction of the source field. It has never been validated experimentally
• Critical state model
(beam model)
• Vector model
REFERENCES:1. Superconductor Magnetization Modelling for the Numerical Calculation of Field Errors in Accelerator Magnets2. Magnetization Measurements of High-Jc Nb3Sn strands
5
Strand Magnetization
Susana Izquierdo Bermudez
0.0 0.5 1.0 1.5 2.0 2.5 3.0-300
-200
-100
0
100
200
300
400
Strand magnetization, OST RRP 108/127 1.9 K (QXF)
Scalar model Critical State ModelB [T]
M [k
A/m
]
Significant differences at low field
Analysis for 11T Magnet (Bernhard Auchmann)
First Guess for QXF
• Summers fit• Deff = 50 µm (should be 56 µm!)
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Impact of Strand Magnetization in b6
Susana Izquierdo Bermudez
Persistent Currents not Considered
Persistent Currents Considered Δb6
Iron yoke not considered -5.86 -7.10 -1.24
Non-linear iron yoke 0.36 -0.52 -0.88
b6 @ Rref = 50 mm, I = Inom (17 kA)
0 2000 4000 6000 8000 10000 12000 14000 16000-300.00-200.00-100.00
0.00100.00200.00300.00400.00500.00600.00700.00
b6 (Rref = 50 mm)
PC considered (non-linear iron yoke)PC not considered (non-linear iron yoke)PC considered (no iron yoke)PC not consider (no Iron yoke)
I (kA)
b6 (u
nits
)
10000 11000 12000 13000 14000 15000 16000 17000-10.00
-8.00-6.00-4.00-2.000.002.004.006.008.00
10.00
I (kA)
b6 (u
nits
)
0.01Inom -> Inom ->0.001Inom->Inom
Current cycle:
Data for second up-ramp:
-0.62 for Deff = 56 µm
Scalar magnetization model
zoom
7
Proposals and Open Questions• Compare magnetization calculations
between Opera and Roxie• Reference design?
• Should we incorporate the impact of coil deformation in the design of QXF cross section?
• Would be very nice to do the analysis in HQ and see how magnetic measurements correlate with ROXIE calculations
Susana Izquierdo Bermudez
Additional slides
Susana Izquierdo Bermudez
9
Nested ellipse model
Susana Izquierdo Bermudez
Superconductor Magnetization Modelling for the Numerical Calculation of Field Errors in Accelerator Magnets
ROXIE magnetization modelo Summers fit, o Deff = 55 µm, o Aleksa/Russenschuck/Völlinger scalar model.
Strand magnetization model consistent with measurements at CERN and FNAL.
Strand magnetization model
Aug. 31, 2012 10B. Auchmann TE-MSC-MDT
Courtesy E. Barzi
11
Algorithm for the calculation of persistent currents as incorporated in the field computation program ROXIE.
1. Superconductor Magnetization Modelling for the Numerical Calculation of Field Errors in Accelerator Magnets
12Susana Izquierdo Bermudez
I=Inom