A particle-beam weapon uses a powerful beam of tiny particles, such as atoms or smaller particles, to harm a target by breaking its structure. This type of weapon is a kind of space-based directed-energy weapon that sends focused energy toward a target using particles at the atomic level. Some particle-beam weapons may one day be used for practical purposes, such as stopping enemy missiles or detecting threats. These weapons have been called by many names, including particle accelerator guns, ion cannons, proton beams, lightning rays, and rayguns.

The idea of particle-beam weapons is based on scientific experiments and theories. One method involves heating a target until it stops working. However, after many years of research, particle-beam weapons are still in the testing phase, and it is unclear if or when they will be used as effective military tools.

Particle accelerators are a well-known technology used in science. They use electromagnetic forces to speed up and guide charged particles along a path, and a magnetic lens system helps focus these particles on a target. The cathode-ray tube in old televisions and computer monitors is a basic example of a particle accelerator. More advanced types, like synchrotrons and cyclotrons, are used in nuclear research. A particle-beam weapon is a military version of this technology. It speeds up charged particles, such as electrons, protons, or ions, to nearly the speed of light and sends them toward a target. The energy from these particles causes extreme heat on the target’s surface and can damage electronic systems when the particles go deeper. However, many accelerators used in nuclear research are very large (sometimes as long as kilometers, like the Large Hadron Collider) and require special conditions to operate. If an accelerator is to be used in space, it must be lightweight and strong enough to survive the environment.

Beam generation

Charged particle beams naturally spread out because the particles push away from each other, and they are bent by Earth’s magnetic field. Neutral particle beams (NPBs) can stay more focused and are not bent by Earth’s magnetic field. Neutral particle beams are first made into ions, then sped up while still charged, and finally made neutral again before leaving the device. Neutral beams also help reduce electrical buildup on spacecraft.

Particle accelerators can speed up negatively charged hydrogen ions to speeds close to the speed of light. Each ion has energy between 100 and 1,000+ MeV. These high-energy negative hydrogen ions can be made neutral by removing one electron from each ion in a special chamber. This creates a beam of neutral hydrogen atoms that move in a straight line at nearly the speed of light to hit a target.

The beam can carry up to 1 gigajoule of energy. The speed of the beam, combined with the energy it delivers to the target, was thought to make defense against it impossible. In 1984, experts believed that protecting targets with shields or special materials was not practical or effective, especially if the beam could stay powerful and focused. Neutral particle beams with much less energy could also be used to find nuclear weapons in space without damaging them.

History

The U.S. Strategic Defense Initiative created a neutral particle beam system to be used as a weapon or to detect nuclear weapons in space. Technology for this system was developed at Los Alamos National Laboratory in New Mexico. A prototype neutral particle beam accelerator was sent into space aboard a suborbital rocket named Aries in July 1989 as part of the Beam Experiments Aboard Rocket (BEAR) project. It reached an altitude higher than 200 kilometers and operated successfully on its own in space before returning to Earth without damage. In 2006, the BEAR accelerator was moved from Los Alamos to the Smithsonian Air and Space Museum in Washington, D.C.