https://motherboard.vice.com/en_us/...oor-magnetic-field-ever?utm_source=reddit.com
Instead of using TNT to generate their magnetic field, the Japanese researchers dumped a massive amount of energy—3.2 megajoules—into the generator to cause a weak magnetic field produced by a small coil to rapidly compress at a speed of about 20,000 miles per hour. This involves feeding 4 million amps of current through the generator, which is several thousand times more than a lightning bolt. When this coil is compressed as small as it will go, it bounces back. This produces a powerful shockwave that destroyed the coil and much of the generator.