Levitated dipole

Charged particles entering the field tend to follow the lines of force, moving north or south.

This strengthening field can cause particles below a certain energy threshold to reflect, and begin travelling in the opposite direction.

The mirror ultimately proved to be "leaky"; the fuel refused to properly reflect from the ends as density and energy increased.

Particles with higher energy, those that would escape a traditional mirror, instead follow the field lines through the hollow center of the magnet, recirculating back into the equatorial area.

This compression effect was first noticed by Akira Hasegawa (of the Hasegawa-Mima equation) after participating in the Voyager 2 encounter with Uranus.

[4] In October 2024, OpenStar Technologies created a cloud of ionized helium contained by a dipole levitated by a permanent magnet.