Current Loop equivalent to Earth's Magnetic Field

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SUMMARY

The discussion centers on calculating the current required in a superconducting loop around the Earth's magnetic equator to replicate the Earth's magnetic field, which is approximately 31 microTesla at the equator and 58 microTesla at 50 degrees latitude. An initial estimate suggests that around 20 megaamperes (MA) would be necessary if the Earth were replaced by a vacuum. However, the presence of the Earth's iron content may reduce this requirement. The participant references the US/UK World Magnetic Model for 2010-2015 as a key resource for accurate data.

PREREQUISITES
  • Understanding of magnetic field concepts, specifically Earth's magnetic field strength.
  • Familiarity with superconductivity and its implications for electrical current.
  • Knowledge of the formula B=uI/2R for calculating magnetic fields from currents.
  • Basic grasp of magnetic permeability and its variations in different materials.
NEXT STEPS
  • Research the US/UK World Magnetic Model for 2010-2015 for detailed magnetic field data.
  • Explore advanced calculations of magnetic fields from currents in spherical geometries.
  • Investigate the effects of Earth's iron content on magnetic field strength and current requirements.
  • Study superconducting materials and their properties in relation to high current applications.
USEFUL FOR

Physicists, electrical engineers, and researchers interested in electromagnetism, superconductivity, and geophysics will benefit from this discussion.

.Scott
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I'm trying to get a feel for the overall magnitude of the Earth's magnetic field.

If I placed a superconducting belt around the Earth magnetic equator, how much current would that loop have to carry to approximate the Earth magnetic field?

Currently, the field at the equator is about 31 microT and at 50 degrees latitude is about 58 microT.

If I replace the Earth with a vacuum, it looks like I would need on the order of 20MA - but I have no confidence in that estimate. It looks to me as though the Earth's iron content might bring this number down.
 
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Bobbywhy said:
This document appears to have all the necessary data to answer your questions:

The US/UK World Magnetic Model for 2010-2015
http://www.ngdc.noaa.gov/geomag/WMM/data/WMM2010/WMM2010_Report.pdf

That all very incredibly detailed - but I would settle for and answer that's off by a factor of 2.
I have the basic data and the B=uI/2R formula (for the center of a current ring). What I don't have is any experience calculating magnetic fields directly from currents - so I am very uncertain of my computations.

Also, the B=uI/2R is for the center of a current ring, not on the surface of a sphere girdled by a current ring - so I don't have a direct comparison. The B=uI/2R also assumes a constant permeability (u) which is not the case of a solid sphere hanging in a vacuum.
 

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