Halo Alpha
Halo Alpha

For the Particle Beam Rifle, see here.


A Beam Rifle, an example of a particle beam weapon.

A particle beam weapon is a type of directed energy weapon that uses an ultrahigh-energy beam of particles (e.g. atoms or electrons) to damage a material target by hitting it, and thus disrupting its atomic and molecular structure. A particle beam weapon is a type of directed-energy weapon which directs energy in a particular direction by a means of particle projectiles with mass. Some of these weapons are real or practicable; some are science fiction.

An electron particle beam weapon works by disrupting electric circuits and electronic devices in its targets. If any living animals or persons were to be caught by the electric discharge of an electron beam weapon, they would most likely be electrocuted. An electron beam weapon can also damage or melt its target by the electrical resistance heating of the target.

Beam generation[]

A neutral particle beam weapon ionizes hydrogen gas by either stripping an electron off of each hydrogen atom, or by allowing each hydrogen atom to capture an extra electron. When hydrogen gains electrons, it forms anions; when hydrogen atoms lose electrons they form cations. A particle beam weapon that accelerates anions uses a travelling wave type particle accelerator. In this kind of ion accelerator, the negative ions are released inside a cylindrical ion acceleration chamber. This chamber has an electrode with an alternating electric charge of up to 1,000,000,000 (10^9) volts inside it.[1] This is a theoretical weapon.

These stages happen:-

  1. While the charge on the electrode is positive, the ions are attracted to the negative charge on the electrode, and thus bunched around it.
  2. The alternating voltage switches the charge to negative on the accelerating electrode.
  3. The negative charge electrostatically repels the negative ions and accelerates them to near the velocity of light.
  4. The resulting high energy beam of anions passes through a chamber filled with low pressure gas.
  5. There, collisions with the gas strip the extra electrons from the anions, and thus make the particle beam neutral.
  6. The particle beam proceeds straight to its target, and damages it by running into it, and by disrupting the structure of the target with its kinetic energy.

Cyclotron particle accelerators, linear particle accelerators, and synchroton particle acclerators can accelerate positively charged hydrogen ions until their velocity approaches the speed of light, and each individual ion has a kinetic energy range of 100 MeV to 1000 MeV or more. Then the resulting high energy protons can capture electrons from electron emitter electrodes, and be thus electrically neutralized. This creates an electrically neutral beam of high energy hydrogen atoms, that can proceed straight line at near the velocity of light to zap its target and thus damage it.[1]

The pulsed particle beam emitted by a particle beam weapon may contain up to 1 gigajoule of kinetic energy or more. The speed of a beam approaching the speed of light (186,000 miles per second) in combination with the energy created by the weapon would negate any realistic means of defending a target against the beam. Target hardening through shielding or materials selection would be impractical or ineffective, especially if the beam can be generated successfully and pointed at the target.[1]

Known particle beam weapons[]

So far, even though humans have an understanding of this technology only the Covenant have shown an adeptness at using practical particle beam weapons, equipping their larger warships with Energy projectors capable of devastating shots, and using the far smaller Type-50 Sniper Rifle System as a high-accuracy anti-personnel weapon.


  1. 1.0 1.1 1.2 "Introducing the Particle-Beam Weapon" Roberds, Richard M (July–August 1984).