Orders of magnitude (magnetic field).html



This page lists examples of magnetic field B in tesla produced by various different sources of energy. 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/meter. Magnetic field B (also known as magnetic flux density or magnetic induction) has SI units tesla. One tesla is equal to 10⁴ gauss.
• Magnetic field drops off as the square of the distance from the source. These examples attempt to make the measuring point clear, usually the surface of the item mentioned.

Below 1 Tesla

attoteslas (10^-18 tesla)

• 5 aT -SQUID magnetometers on Gravity Probe B gyros measure fields at this level over several days of averaged measurements ¹

femtoteslas (10^-15 tesla)

• 2 fT -SQUID magnetometers on Gravity Probe B gyros measure fields at this level in about one second

picoteslas (10^-12 tesla)

• 0.1 - 1.0 pT - human brain magnetic field
• 10 pT (1.0×10⁻¹¹ tesla) - 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 1²

nanoteslas (10^-9 tesla)

• 0.1 nT to 10 nT - magnetic field strength in the heliosphere

microteslas (10^-6 tesla)

• 31 µT (3.1×10⁻⁵ T) - 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

milliteslas (10^-3 tesla)

• 5 mT - the strength of a typical refrigerator magnet [2]
• 150 mT (0.15 tesla) - the magnetic field strength of a sunspot

Between 1 and 1000 tesla

The strongest (non-pulsed) magnet in the world is located at NHMFL in Tallahassee, Florida, USA.

tesla

• 1 T to 2.4 T - coil gap of a typical loudspeaker magnet³.
• 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, and 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 T⁵⁶
• 11.7 T – field strength of a 500 MHz NMR spectrometer
• 16 T - required strength to levitate a frog⁷
• 45 T - strongest continuous magnetic field yet produced in a laboratory (Florida State University's National High Magnetic Field Laboratory in Tallahassee, USA)⁸.
• 100 T - strongest (pulsed) magnetic field yet obtained non-destructively in a laboratory (Los Alamos National Laboratory)⁹¹⁰

Above 1000 tesla

kilotesla (10³ tesla)

• 2.8 kT - strongest (pulsed) magnetic field ever obtained (with explosives) in a laboratory (VNIIEF in Sarov, Russia, 1998)¹¹

megateslas (10⁶ tesla)

• 1 to 100 MT (10⁶ T to 10⁸ T) - strength of a neutron star

gigateslas (10⁹ tesla)

• 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).
3. ^ Elliot, Rod. "Power Handling Vs. Efficiency". Retrieved on 2008-02-17.
4. ^ The Tesla Radio Conspiracy
5. ^ Smith, Hans-Jørgen. "Magnetic resonance imaging". Medcyclopaedia Textbook of Radiology. GE Healthcare. Retrieved on 2007-03-26.
6. ^ Orenstein, Beth W. (2006-02-16), "Ultra High-Field MRI — The Pull of Big Magnets", Radiology Today 7 (3): 10, http://www.radiologytoday.net/archive/rt21606p10.shtml, retrieved on 10 July 2008 
7. ^ "Frog defies gravity".
8. ^ "World's Most Powerful Magnet Tested Ushers in New Era for Steady High Field Research". National High Magnetic Field Laboratory.
9. ^ "Laboratory sets high magnetic field records". LANL (2006-08-31).
10. ^ "One-of-a-kind magnet open for science". PhysOrg.com (2006-10-25).
11. ^ "With record magnetic fields to the 21st Century". IEEE Xplore.