Fusor
The fusor is a nuclear fusion device which uses electrostatic fields confine the ions. It is also referred to as an inertial electrostatic confinement device (IEC).
Introduction
In general, a fusor consists of two concentric electrodes between which a potential difference is applied. Ions and electrons that are introduced or created between the electrodes are accelerated by the electric field. For fusion purposes, the inner electrode is the cathode, i.e. it is at negative potential, and the cathode is made mostly transparent. Therefore, the ions are accelerated radially inwards and will pass through the cathode. So, the ions will exhibit an oscillary motion in radial direction. As the ions converge radially inwards they will obtain a fusion relevant energy due to the electrostatic field. Collisions of these high energy ions with either other high energy ions or background neutrals can result in fusion. Additionally, there is a large probability on a charge exchange reaction of the fast ion, creating a fast neutral. Collisions of these fast neutral with other particles can also results in fusion.
Fusion performance
Although the fusor is a relatively simple device to create fusion, it is not very efficient. The energy efficiency, the ratio between the fusion energy gained and the energy used for operating the fusor, is typically in the range to for deuterium-deuterium fusion reactions. It has been shown theoretically that the fusor concept cannot produce energy gain.
Fusor applications
The fusor cannot be used to produce energy, but it still produces neutrons in a relatively cheap and simple way. These neutrons can be used for various application, such as explosives detection, nuclear material detection and medical isotope production.