Japanese scientists record largest magnetic field
© Windell Oskay / CC BY 2.0.
Nakamura et al record highest magnetic field ever achieved indoors.

Physicists from the Institute for Solid State Physics at the University of Tokyo, Japan, have recorded the largest magnetic field ever generated indoors - a whopping 1,200 T (tesla).


"Magnetic fields are one of the fundamental properties of a physical environment," said lead author Dr. Daisuke Nakamura and colleagues.

"They can be controlled with high precision and interact directly with electronic orbitals and spins; this makes them indispensable for research in areas of solid state physics such as magnetic materials, superconductors, semiconductors, strongly correlated electron materials, and other nanomaterials."

The researchers generated ultrahigh magnetic fields using the electromagnetic flux-compression (EMFC) technique.

"We developed a high performance EMFC instrument to generate a megagauss magnetic field," they said.

"The conversion efficiency of the electric energy stored in condenser banks to the imploding liner kinetic energy was found to be substantially improved in comparison to those in previous instruments."

"The magnetic field was measured by the reflection-type Faraday rotation probe using an optical fiber, and a peak field of 1,200 T was recorded."

By comparison, this is a field strength about 400 times higher than those generated by the huge, powerful magnets used in modern hospital MRI machines, and it is about 50 million times stronger than the Earth's own magnetic field.

Schematic view of the EMFC megagauss generator;
© Nakamura et al, doi: 10.1063/1.5044557.
(a) Schematic view of the EMFC megagauss generator; (b) cross section of (a); (c) copper-lined primary coil and a pair of seed field coils; in (a), one of the initial seed field coils is presented in the displaced position, for more visible view of the primary coil; the primary coil is covered by an anti-explosive block made of bulk iron-steel, which is omitted in the drawing (a).
Stronger magnetic fields have previously been achieved in outdoor experiments using chemical explosives, but this is a world record for magnetic fields generated indoors in a controlled manner.

That greater control means the discovery could open new frontiers in solid-state physics, perhaps allowing scientists to reach what is known as the 'quantum limit,' a condition where all the electrons in a material are confined to the lowest ground state, where exotic quantum phenomena may appear.

"This work opens up a new scientific horizon and has pushed the envelope for ultrahigh magnetic fields," Dr. Nakamura said.

The team's results appear in the journal Review of Scientific Instruments.

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D. Nakamura et al. 2018. Record indoor magnetic field of 1200 T generated by electromagnetic flux-compression featured. Review of Scientific Instruments 89: 095106; doi: 10.1063/1.5044557