Helically Symmetric Experiment

The Helically Symmetric Experiment (HSX, stylized as Helically Symmetric eXperiment), is an experimental plasma confinement device at the University of Wisconsin–Madison, with design principles that are intended to be incorporated into a fusion reactor. The HSX is a modular coil stellarator which is a toroid-shaped pressure vessel with external electromagnets which generate a magnetic field for the purpose of containing a plasma.

Source: Wikipedia — Helically Symmetric Experiment (CC BY-SA 4.0)