Fusor

A fusor is a device that uses an electric field, rather than a magnetic one, to heat ions to the temperature needed for nuclear fusion, making it one type of inertial electrostatic confinement device. Two metal cages sit inside a vacuum chamber with a voltage held between them, so positive ions accelerate toward the negatively charged inner cage, gaining speed as they fall through the voltage drop, and fusion can occur when ions collide near the center. Television pioneer Philo T. Farnsworth conceived the fusor in the early 1960s, drawing on his earlier work with vacuum tube designs, and Robert L. Hirsch refined the design in 1967 into what became its most common form; despite promising early results, the United States Atomic Energy Commission chose to prioritize tokamak research over the fusor and similar alternative concepts. Fusors are not used to generate power today, but commercial versions generate neutrons for industrial use and produce medical isotopes such as technetium-99m, and the device has also become popular among hobbyists building working nuclear fusion machines at home, supported by communities such as Fusor.net.