The polywell is a proposed design for a fusion reactor using an electric and magnetic field to heat ions to fusion conditions.
A homemade fusor
Farnsworth–Hirsch fusor during operation in so called "star mode" characterized by "rays" of glowing plasma which appear to emanate from the gaps in the inner grid.
Figure 2: A plot of the magnetic field generated by the MaGrid inside a polywell. The null point is marked in red in the center.
Figure 4: Illustration of single electron motion inside the polywell. It is based on figures from "Low beta confinement in a polywell modeled with conventional point cusp theories" but is not an exact copy.
Fusion power is a proposed form of power generation that would generate electricity by using heat from nuclear fusion reactions. In a fusion process, two lighter atomic nuclei combine to form a heavier nucleus, while releasing energy. Devices designed to harness this energy are known as fusion reactors. Research into fusion reactors began in the 1940s, but as of 2024, no device has reached net power, although net positive reactions have been achieved.
The Joint European Torus (JET) magnetic fusion experiment in 1991
Early photo of plasma inside a pinch machine (Imperial College 1950–1951)
The UK claimed that it had gotten fusion first in 1957 on ZETA, but this claim had to later be withdrawn.
Magnetic mirrors suffered from end losses, requiring high power, complex magnetic designs, such as the baseball coil pictured here.
