Things did not exactly go as planned when researchers at the University of Tokyo set out to create test the properties of a new generator system. Instead, they managed to create the strongest magnetic field ever created indoors, which led to them blowing off the doors to their lab.
Strongest Magnetic Field in a Controlled Environment
A paper in the “Review of Scientific Instruments” revealed the researchers wanted to reach a peak magnetic field with an intensity of about 700 Teslas. However, in reality, they produced 1,200 Teslas. Bear in mind that the standard refrigerator magnet is only about 0.01 Tesla. While they did not mean to do it, they essentially made the strongest magnetic field in a controlled environment indoors.
However, they do have some way to go before they can claim to have generated the strongest ever field. Russian researchers did this in 2001 when they created more than twice the strength at 2,800 Teslas.
Researchers Did Not Use TNT But Still Blew the Door Off
To create the magnetic fields the researchers used “electromagnetic flux-compression”, a technique that researchers have used since the 1940s. A spike that is only brief is caused in the magnetic fields strength as it is squeezed rapidly into a smaller size. During the 1940s this technique relied on large amounts of TNT being used in order to generate an explosion that was powerful enough to cause the magnetic field to compress. The downside to this, of course, was that the technique could only be used once due to the fact the equipment was totally destroyed by the blast caused by the TNT.
The researchers in Japan wanted more control over the explosion to cause the magnetic field to compress so they refrained from using TNT, instead dumping huge amounts of energy by of 3.2 megajoules, into the generator. In order to do this, the researchers had to feed 4 million amps of current in the generator. To put this into perspective it is several thousand times that of a lightning bolt. When the coil is tightly compressed and will not go any further a shockwave is produced destroying the generator along with the coil.
In order to provide themselves with protection to keep them safe, the researchers constructed an iron cage, placing the generator inside it. While this was a good idea, the cage they constructed had only been made to be able to withstand up to 700 Teslas at the most. Of course, things went awry when they produced 1,200 Teslas by accident, which resulted in the door to the iron cage being blown off.
Researcher Admitted He Did Not Expect Magnetic Field to be so high
Shojiro Takeyama was among the researchers at the University of Tokyo taking part in the experiment. He said, “I didn’t expect it to be so high.” “Next time, I’ll make [the enclosure] stronger.”
A new iron cage was made and the researchers made some adjustments and are giving the experiment another attempt. They are planning to generate only 1,500 Teslas by pumping 5 megajoules of energy into the generator.
In conclusion, the researchers said:
“Only 40 years ago, magnetic fields of the order of 1000 Tesla were only reported in extremely complicated and sometimes unreliable explosively-driven systems, without any of the sophisticated levels of control. Therefore, one can say without any doubt, that the present results represent the beginning of a new era in the quest of producing and using ultrahigh magnetic fields for solid-state studies as well as for plasma fusion related experiments.”