Magnets from Mini to Mighty

1
Magnets From Mini to Mighty Mark D. Bird,
Ph.D. Director, Magnet Science and
Technology Open House 2008
1.7m
Supported by
2
NHMFL Leads the World in High-Field Magnet
Technology
Numerous other high-performance pulsed, powered,
persistent systems
3
What is a Magnet?
Smiley 0.092 Teslas Rare Earth 0.38 Teslas Rare
Earth 4 Smileys
4
Types of Magnets
Permanent magnets
Electromagnets
900 MHz NMR magnet Used to study Tuberculosis,
brain imaging, etc.
21.1 T 229 Smileys See It Today!
0.1 0.4 T
5
Simple Electromagnet
Construction Copper wire w/ insulation Steel
Bar Battery Intensity 0.030 Tesla Smiley
3 Lift 1 oz steel
6
Door Lock Electromagnet
7
Door Lock Electromagnet
Construction Copper wire w/ insulation Steel
Core Yoke Battery Intensity 0.005 Tesla
Simple 6 Lift 250 pounds of steel Intensity ?
Force
8
Types of Magnets
Permanent Magnets
Electromagnets
0.1 T 0.4 T
0.030 T
0.005 T
High-Field Magnets 5 T 100 T
100 T 3333 Simple Magnets
9
Joule Heating
Electric Current Heat!!! (normally)
Examples Lightbulb Electric Heater Electric
Stove Computer
Will the High-Field Magnet Melt?
10
Magnetic (Lorenz) Forces
Electric Current Intense Magnetic Fields
Force
Uses of Electric Motors Garage Goor Openers
Elevators Clothes Washer Clothes Dryer Electric
Windows
Intensity lt1T
Will the High-Field Magnet Explode?
11
Pulsed Magnet
Construction Heavy Copper wire w/
insulation Epoxy Zylon Steel Liquid nitrogen
Cooling (-330 ºF) Intensity 80 T
12
Will the Pulsed Magnet Explode?
High-strength copper alloy (stronger than
ordinary steel) Zylon (bullet-proof
vests) High-strength steel shells Steel
Bolts Epoxy
13
Pulsed Magnet
Will the Pulsed Magnet Melt?
Cool with Liquid Nitrogen at -330 ºF
Pulse 20,000 Amps for 0.01 s
Final Temperature 40 ºF 370 degree change in
0.01s
14
Types of Magnets
Permanent magnets 0.1 T 0.4 T
Simple Electromagnets 0.03 T
High-Field Magnets 25 - 100 T
Pulsed
80 T 370 ºF in 0.01 s
Will it melt? Can we cool it?
15
Steady Magnets
Construction Copper Sheet w/ cooling holes
Insulation Bolts Cooling Water Intensity 27
T Steady-state! Levitates water
Bitter Disk Named after Prof. Francis Bitter
16
Will it Break?Stress Concentrations Round Hole
17
Will it Break?Stress Concentrations Elongated
Hole
Less material, roughly twice as strong as round
holes
18
FLORIDA-BITTER MAGNETS
Traditional Round Holes weaken the disk!
Elongated Holes make the magnet stronger, reduce
power by 40!
19
POWERED MAGNET HISTORY _at_ NHMFL
World Records!
World Records!
See them on the tour!
20
Florida-Bitter 700 12 210 45 100,000
Lightbulb 310 64 3300 0.008 28
Pulsed 5000 12 -330 to 40 80 280,000
Current Density (A/mm2) Power Density
(W/mm3) Temperature (F) Field (T) Stress (psi)
21
Types of Magnets
Permanent magnets 0.1 T 0.4 T
Electromagnets 0.03 T
High-Field Magnets 5 100 T
Can we build steady, High-Field Magnets without
power?
Florida-Bitter 35 - 45 T steady
Pulsed 80 T 0.01 s
20,000 Amps 0 Volts 0 Power
4,000,000 each year for electricity!
22
Superconducting Cable-in-Conduit
Superconducting Wire carries current without
voltage, without power. No Electric Bill!
23
Superconducting Coil
4 ft
Main Coil
Shield Coil
24
Superconducting Magnet
See it in Today!
Liquid Helium (-450 ºF) Intensity 15
T Steady-state ?No Power!
Construction Superconducting Wire Steel
Conduit Insulation Epoxy
25
Superconducting Magnet
Will the Cable-In-Conduit magnet Explode? Steel
Conduit supports Lorenz forces Will the CICC
magnet melt? Helium eliminates heating!
5.5 ft
26
Superconducting Magnet for Electric Power
Generation!
The International Thermonuclear Experimental
Reactor will fuse Hydrogen to make Helium
electric power. Under Construction in France, w/
US (and NHMFL) participation. gt10,000,000,000
Person!
ITER - FRANCE
27
Synergy in NHMFL Work-for-Others
Contractsaddressing magnet needs around the
world
Nijmegen Resistive Magnets - NETHERLANDS
m-collider/n-factory - BROOKHAVEN
Thank You!
ANL-APS Undulator - ARGONNE
MSU Sweeper - MICHIGAN
BWXT 100MJ Superconducting Magnetic Energy Storage
IPR-India SST1 - INDIA