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.

The lack of this large externally driven plasma current makes stellarators suitable for steady-state fusion power plants.

However, due to non-axisymmetric nature of the fields, old stellarators have a combination of toroidal and helical modulation of the magnetic field lines, which leads to high transport of plasma out of the confinement volume at fusion-relevant conditions, solved in the Wendelstein 7-X which has a better particle confinement than the expected in ITER, and achieve plasma duration of 30 minutes.

A set of auxiliary coils is used to deliberately break the symmetry to mimic conventional stellarator properties for comparison.

[citation needed] Experiments have shown that edge magnetic islands affect particle fueling and exhaust.

[citation needed] These include: A large number of experimental and computational research works are being done in HSX by students, staff and faculties.