Orders of magnitude (magnetic field)

This page lists examples of magnetic field B in teslas produced by various different sources. They are grouped by orders of magnitude, and each section covers three orders of magnitude, or a factor of one thousand.

Note:

• Traditionally, magnetizing field H, is measured in amperes per meter. Magnetic field B (also known as magnetic flux density or magnetic induction) has SI units teslas. One tesla is equal to 10⁴ gauss.
• Magnetic field drops off as the cube of the distance from the source (for a dipole). These examples attempt to make the measuring point clear, usually the surface of the item mentioned.

List of orders of magnitude for magnetic fields

Factor (tesla)	SI prefix	Value	Item
10−18	attotesla	5 aT	SQUID magnetometers on Gravity Probe B gyros measure fields at this level over several days of averaged measurements[1]
10−15	femtotesla	2 fT	SQUID magnetometers on Gravity Probe B gyros measure fields at this level in about one second
10−12	picotesla	0.1 - 1.0 pT	human brain magnetic field
10−11		1.0×10−11	In September 2006, NASA found "potholes" in the magnetic field in the heliosheath around our solar system that are 10 picoteslas as reported by Voyager 1[2]
10−9	nanotesla	0.1 nT to 10 nT	magnetic field strength in the heliosphere
10−6	microtesla	24 µT	strength of magnetic tape near tape head
10−5		31 µT	strength of Earth's magnetic field at 0° latitude (on the equator)
		58 µT (5.8×10−5 T)	strength of Earth's magnetic field at 50° latitude
10−3	millitesla	0.5 mT	the suggested exposure limit for cardiac pacemakers by American Conference of Governmental Industrial Hygienists (ACGIH)
		5 mT	the strength of a typical refrigerator magnet [2]
10−1		0.15 T	the magnetic field strength of a sunspot
100	tesla	1 T to 2.4 T	coil gap of a typical loudspeaker magnet[3].
		1.25 T	strength of a modern neodymium-iron-boron (Nd2Fe14B) rare earth magnet. A coin-sized neodymium magnet can lift more than 9 kg, can pinch skin and erase credit cards.[4]
		1.5 T to 3 T	strength of medical magnetic resonance imaging systems in practice, experimentally up to 8 T[5][6]
		9.4 T	Modern high resolution research magnetic resonance imaging system
101		11.7 T	field strength of a 500 MHz NMR spectrometer
		16 T	strength used to levitate a frog[7]
		36.2 T	strongest continuous magnetic field produced by non-superconductive resistive magnet.[8]
		45 T	strongest continuous magnetic field yet produced in a laboratory (Florida State University's National High Magnetic Field Laboratory in Tallahassee, USA)[9].
		91.4 T	strongest (pulsed) magnetic field yet obtained non-destructively in a laboratory (Forschungszentrum Dresden-Rossendorf)[10]
102		730 T	strongest pulsed magnetic field yet obtained in a laboratory, destroying the used equipment, but not the laboratory itself (Institute for Solid State Physics, Tokyo)
103	kilotesla	2.8 kT	strongest (pulsed) magnetic field ever obtained (with explosives) in a laboratory (VNIIEF in Sarov, Russia, 1998)[11]
106	megatesla	1 to 100 MT (106 T to 108 T)	strength of a neutron star
109	gigatesla	0.1 to 100 GT (108 to 1011 T)	strength of a magnetar

References

1. ^ [1] Gravity Probe B
2. ^ "Surprises from the Edge of the Solar System". NASA. 2006-09-21. http://science.nasa.gov/headlines/y2006/21sep_voyager.htm?list823631. 
3. ^ Elliot, Rod. "Power Handling Vs. Efficiency". http://sound.westhost.com/articles/pwr-vs-eff.htm. Retrieved 2008-02-17. 
4. ^ The Tesla Radio Conspiracy
5. ^ Smith, Hans-Jørgen. "Magnetic resonance imaging". Medcyclopaedia Textbook of Radiology. GE Healthcare. http://www.medcyclopaedia.com/library/radiology/chapter04/4_5.aspx. Retrieved 2007-03-26. 
6. ^ Orenstein, Beth W. (2006-02-16). "Ultra High-Field MRI — The Pull of Big Magnets". Radiology Today 7 (3): pp. 10. Archived from the original on March 15, 2008. http://web.archive.org/web/20080315222846/http://www.radiologytoday.net/archive/rt21606p10.shtml. Retrieved 2008-07-10 
7. ^ "Frog defies gravity". http://www.newscientist.com/article/mg15420771.600-frog-defies-gravity.html. 
8. ^ "Mag Lab Reclaims World Record for Highest Field Resistive Magnet". http://www.magnet.fsu.edu/mediacenter/news/pressreleases/2010/2010january-36t.html. 
9. ^ "World's Most Powerful Magnet Tested Ushers in New Era for Steady High Field Research". National High Magnetic Field Laboratory. http://www.magnet.fsu.edu/mediacenter/news/pressreleases/1999december17.html. 
10. ^ "The Highest Magnetic Fields...". HZDR. 2011-06-28. http://www.hzdr.de/db/Cms?pOid=33768&pNid=473. 
11. ^ "With record magnetic fields to the 21st Century". IEEE Xplore. http://ieeexplore.ieee.org/xpl/freeabs_all.jsp?arnumber=823621.