Magnetic fields in science and technology
In nature, the magnetic field acts as a fundamental thermodynamic property like temperature or pressure. For this, the magnetic field plays a decisive role in many facets of nature, and in consequence, is of importance in several natural sciences. In particular, the understanding of magnetic properties of matter and the interplay of magnetism with other quantities is a challenging field of research. Under extreme conditions, like low temperatures, high pressures, and high magnetic fields, new interesting properties of matter can appear and the understanding of materials properties can crucially be gained.
Further, the manifold magnetic effects in nature and in particular the magnetic properties of matter are a rich source for technological innovations. Historically, there is an immense number of inventions like the compass, electro motor, generator, relay, magnetic brake, levitating train, nuclear magnetic resonance tomograph, hard disk drive, magneto-electric random access memory. Nowadays, in transport, energy production, medicine, communication, data storage, and other areas of daily live, magnetic systems, components, and properties are used in a large variety.
In the last decades, the application of high magnetic fields became a powerful research tool. Especially in solid state physics important discoveries like the integer quantum Hall effect and fractional quantum Hall effect (both honored with the Physics Nobel Prize) as well as appropriate investigations in graphene (Physics Nobel Prize 2010), are based on experiments in very high magnetic fields.
In order to establish a large modern user facility with unique experimental possibilities for science in high magnetic fields and in order to provide an easy access for the high field community in Europe, the Dresden High Field Project has been started. The facility has been built up during 2003 to 2006. Since 2007, the Dresden High Magnetic Field Laboratory (HLD) operates as a user facility for experiments in ultra-high pulsed magnetic fields up to 100 T.
Magnetic fields in laboratories and nature
Technically feasible magnetic fields
|Method||Field value||Duration||Laboratory (assortment)|
|Intensive laser irradiation of solids (sample is in plasma state)||34 000 T||10 ps|
|Explosive flow compression (Experimental set-up will be destroyed)||2 800 T||μs||Sarov|
|Electromagnetic flux compression (coil will be destroyed)||620 T||μs||Tokyo|
|Coil with one or a few convolutions (will be destroyed)||300 T||μs||Tokyo, Toulouse, Los Alamos|
|Pulsed coils||100 T||10-3 to 1 s||Dresden (94,2 T), Los Alamos (100 T), Toulouse (82,0 T), Tokyo, Wuhan, Leuven, Oxford|
|Hybrid magnet (resistive + superconducting)||45 T||static||Tallahassee|
|Resistive electro magnets||38 T||static||Grenoble, Tallahassee, Nijmegen|
|Superconducting magnet systems (conventional and high temperature-superconductor)||27 T||static||Tallahassee (achieved in 2015)|
|Superconducting magnets (conventional)||22 T||static||commercial|
|Coils with iron yoke||2 T||static||commercial|
Typical magnet fields in nature
|Neutron star||108 T|
|White dwarfs||104 T|
|Internal exchange fields of ferromagnets||101 to 103 T|
|Surface of ferromagnets||10-1 to 101 T|
|Earth||10-5 to 10-4 T|
|Technical scattering fields "urban noise"||10-12 to 10-5 T|
|Field in galaxies||10-10 T|
|Fields in galaxy accumulations||10-10 to 10-13 T|
|Intergalactic magnetic field||10-13 T|
|Magnetic fields in biology||10-15 to 10-9 T|
- 1 Tesla = 1 T = 1 Vs/m2
- SI Unit of the magnetic flux density, named after Nikola Tesla (1856 - 1943), a Serbian-American electrical engineer and physicist
- 1 Gauss = 1 G = 10-4 T = 0.0001 T
- This magnetic flux density unit was named after Carl Friedrich Gauß (1777 - 1855), a mathematician, astronomer and physicist who also paved the way for modern earth sciences