The Farnsworth-Hirsch fuser uses electric fields to contain fusion plasma, and is simple to build. It cannot generate net power, but related designs show potential for use as a power source. The fuser draws ions into a central cavity, inducing nuclear fusion. Workarounds are proposed to solve problems with ion density and collisions. Alternative designs include the Polywell system and a modified Penning trap. Researchers hope to develop a viable source of fusion energy.
A Farnsworth-Hirsch fuser is a device for generating nuclear fusion reactions. Farnsworth-Hirsch melters use strong electric fields to contain the fusion plasma, unlike the more common tokamak design, which uses magnetic fields. Farnsworth melters are generally quite simple to build, and numerous amateurs have built their own, often from spare parts. While a Farnsworth fuser cannot generate net power from fusion, several related designs show potential, and research is currently underway to determine whether any of them are viable as a power source.
The underlying principle of the Farnsworth fuser, inertial electrostatic confinement (IEC), was first noticed in television vacuum tubes. If you apply an electric field to a plasma, the positively charged ions in the plasma will be attracted to the electric field and the ions will all gather around the region with the lowest electric potential. By arranging the wires in a “grid” shape and then applying a voltage, Farnsworth’s fuser draws the ions into a central cavity. If the voltage is high enough, the electrical attraction will cause the ions to rub through the central cavity at high speed; the ions then collide with other ions moving through the cavity as well, inducing nuclear fusion.
Because the confinement mechanism is so simple, requiring only wires and a high-voltage power supply, Farnsworth melters are fairly simple to build. Blueprints and instructions for building a melter are available on the Internet, often requiring nothing more than a basic understanding of the techniques used and a few thousand dollars of spare parts. Note that these home-built fusers cannot be used as energy sources due to the low number of fusion reactions, although they can be used as sources of neutron radiation.
The power produced by a fuser is limited by the density of the ions; as more ions are injected into the fuser, the ions begin to repel each other, setting an upper limit on the number of collisions. The ions also collide with the grid, sapping their energy and producing unwanted heat. Many workarounds have been proposed to solve these problems, and there are several active research efforts to develop a viable source of fusion energy. Some of the proposed alternative designs include the Polywell system, which uses a network of magnetic coils and an electric field, and a modified Penning trap, which uses a constant electric and magnetic field to confine charged particles. While no one has yet produced usable energy, researchers hope a viable device can be built.
Protect your devices with Threat Protection by NordVPN
