Sep 28, 2018

An explosive, record-breaking magnetic field

The moment of activation. Photo: University of Tokyo

The strongest-ever controlled magnetic field was activated in Tokyo earlier this year, showering a containment room with sparks for its brief lifespan: 1/1,000th of a blink of an eye.

Why it matters: Powerful magnetic fields allow scientists to study the movement of electrons, enabling research into fusion, a future source of clean energy.

The field was measured at 1,200 teslas — a unit of magnetic field strength — which is about 400 times the strength of an MRI, according to IEEE Spectrum.

  • It was created by compressing a much weaker field into a tiny space at an extremely fast rate.
  • Shojiro Takeyama, the University of Tokyo professor in charge of the experiment, told IEEE that the iron cupboard that housed the mechanism was built to withstand the effects of a 700-tesla magnetic field — only three-fifths the strength of the field that was actually created.
  • The cupboard’s door was broken, but no one was hurt, he said.

The magnetic field’s 100 microseconds of existence may seem fleeting, but it’s actually a major record, according to a statement from the University of Tokyo.

  • Powerful fields generated by lasers typically last for nanoseconds — or 1/1,000th of a microsecond.
  • A Russian experiment created a stronger magnetic field in 2001, but it couldn’t be controlled. The 2,800-tesla field blew up the lab’s equipment.

Go deeper: Watch the fireworks as the University of Tokyo field is activated (YouTube)

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