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The Influence of Outbreak Magnetic Field by a Superconducting Magnet for
the surrounding devices and environment
High Energy Accelerator Research Organization(KEK) / Tesuya Yokoo, Ph.D Tohoku University / Kenji Ohoyama, Dr.Sci
ANSYS Japan / Takahiro Koga
Agenda
1. Background 2. Motivation 3. Electromagnetics Analysis 4. Vector Hysteresis Modeling 5. Simulation Model 6. Simulation Results 7. Conclusion
2
Background
Tohoku University and KEK joint project
3
Background
4
Background
5
Background
6
Motivation
• For the under constructing large-scale experimental devices and laboratory, the outbreak magnetic field by the Superconducting Magnet (7 tesla) may adversely affect the environment/system.
• Perform visualization by electromagnetic simulation for remanence magnetization.
• Precision Goal: 10 tesla ~ 10uT order (100,000~0.1 gauss) * Earth magnetism: 46uT (Japan)
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Remanence Magnetization
Hysteresis Loop J
H
H
J
H
J
Permanent Magnet
Iron
Iron
Permalloy
Narrow
Wide
Soft Magnetic Material
Soft/Hard Magnetic Material
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Electromagnetics Analysis
ANSYS Maxwell Applications Motor Actuator Coil, Inductor Transformer RFID Induction Heater Permanent Magnet Sensor Capacitor Electrode
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Vector Hysteresis Modeling
• ANSYS Maxwell has a capability to handle major/minor BH hysteresis loop simulation by transient solver
• Remanence magnetic field at soft magnetic material
Soft magnetic core
Input Current waveform Tracking BH Operating point 10
Simulation Model
• Magnetic Analysis – Superconducting Magnet – Magnetic Devices (Beam Line Devices) – Laboratory Model
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Superconducting Magnet
• Target Point: 6.83 tesla
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Superconducting Magnet
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Far
Mag_B vs. Distance from magnetic source
10mT @ 1 m 1mT @ 2 m
Source 0.7T @ 0.5 m
6.83T @ 0 m
Magnetic Devices (Beam Line Devices)
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Beam Line
Posted with Superconducting Magnet
Solenoid Coil
Guide Magnet1
Helmholtz Coil Guide Magnet2
Guide Magnet3
2.4m
Magnetic Devices (Beam Line Devices)
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Wrapping Permalloy Sheet
Solenoid Coil
Magnet Guide1
Helmholtz Coil Magnet Guide2
Magnet Guide3
Permalloy BH curve
Expanded H
Hci = 4 [A/m]
Magnetic Devices (Beam Line Devices)
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Steel Board Permanent magnet (NdFeB)
Solenoid Coil
Steel BH curve
Magnet Guide1
Magnet Guide2 Magnet Guide3
Helmholtz Coil
Hci = 53 [A/m]
Expanded H
Laboratory Model
17 http://nc-imr.imr.tohoku.ac.jp/instruments.html http://j-parc.jp/researcher/MatLife/ja/instrumentation/ns.html
Laboratory Model
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2.4m
23meter
12m
eter
4.3meter
Laboratory Model
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Iron (SS400) Stainless Concrete
Hci = 80 [A/m]
SS400 BH curve
Expanded H
Major Structure Materials
Input Current
Compared before/after magnetic field by the influence of remanence with the Superconducting Magnet
Helmholtz Coil
Solenoid Coil
Superconducting Magnet
Before After Outbreak 20
Simulation Results
• B Vector plot on Beam Line • Magnetic Field around Beam Line devices • Magnetic Field at Laboratory
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B Vector Plot on Beam Line
• Before/After Bx, By, Bz plot • Devices: No input current
Bx Max. Delta: 0.31 Gauss
( ：Before ／ ：After)
By Max. Delta: 0.071 Gauss
Bz Max. Delta: 2.68 Gauss
Y Scale: -1 ~ 1 Gauss Y Scale: -1 ~ 1 Gauss
Y Scale: 0 ~ 450 Gauss
Beam Line
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B Vector Plot on Beam Line
• Before/After Bx, By, Bz plot • Devices: No input current
Y Sc
ale:
0 ~
30
Gaus
s
Bz Max. Delta: 2.68 Gauss
Beam Line
23 ( ：Before ／ ：After)
Magnetic Field around Beam Line devices
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Before
After
Magnetic Field around Beam Line devices
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Before
After
* Log Scale
* Log Scale
Magnetic Field around Beam Line devices
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After
Outbreak
Magnetic Field around Beam Line devices
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B Vector Field
Magnetic Field Laboratory
Structure under the floor
After
Outbreak
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Magnetic Field Laboratory
Side Wall
After
Outbreak
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Magnetic Field Laboratory
YZ Cross Planes
Scale ~100 Gauss Scale ~100 Gauss
Before After
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Magnetic Field Laboratory
XY, XZ Cross Planes (After)
Scale ~10 Gauss
Scale ~100 Gauss
After
After
31
Magnetic Field Laboratory
Beam Line – Emitting Port
After
Before
Scale ~10 Gauss
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Beam Line – Emitting Port
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Iron structure Stainless structure
Should be change stainless
Conclusion
• We succeed to analyze and visualize the influence of outbreak magnetic field, remanence magnetized soft magnetic material by a Superconducting Magnet with ANSYS Maxwell’s Vector Hysteresis Modeling.
• Magnetic devices on beam line would be magnetized, but not affect.
• Beam emitting port might influence the beam control by remanence -> Need to change design to non-magnetic material e.g. stainless
• Contribute to investigate the prior validation for the large-scale experimental device under construction.
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