Unexpected magnetic fireworks. “During 40 microseconds last April, Shojiro Takeyama and his team at the University of Tokyo dumped 3.2 megajoules of energy into a newly built scientific instrument and blew part of it to smithereens. The smithereens part was expected; the force of the explosion, not quite. The instrument was designed to generate super-strong magnetic fields for examining semiconductors and other materials at the nanometer scale. Takeyama was expecting about 700 Tesla. He got 1200 T instead—a world record for indoor fields and about 400 times as strong as a typical medical MRI.
Bigger magnetic fields have been made before, but they aren’t practical or reliably reproducible, because they rely on rather dangerous amounts of TNT. It is not an indoor activity.
These fields are generated by starting with a strong, unchanging magnetic field and then rapidly—on the order of microseconds—squeezing it. Instead of causing that squeeze with a TNT-fueled implosion, Takeyama used an electrically-induced one.
In such a strong magnetic field, electron motion is confined to a space less than a nanometer across, allowing for new more precise measurements. “In general, the higher the field, the resolution of measurement becomes better and better,” says Takeyama.
The measurements will only get easier. Takeyama is working on making the measurement space a bit bigger—10 mm—to accommodate other instruments. Using the system’s fully-charged, 5-MJ, capacitor bank, that should lead to another record: 1500 T.”