Particle beam
From Wikipedia, the free encyclopedia
A particle beam is an accelerated stream of charged particles or atoms (often moving at very near the speed of light) which may be directed by magnets and focused by electrostatic lenses, although they may also be self-focusing (see Pinch).
Subatomic particles such as electrons, positrons, and protons can be accelerated to high velocities and energies, usually expressed in terms of center-of-mass energy, by machines that impart energy to the particles in small stages or nudges, ultimately achieving in this way very high energy particle beams, measured in terms of billions and even trillions of electron volts. Thus, in terms of their scale, particles can be made to perform as powerful missiles for bombarding other particles in a target substance or for colliding with each other as they assume intersecting orbits.
High energy beams are created in particle accelerators, in which a charged particle is drawn forward by an electrostatic (not magnetic) field with a charge opposite to the particle (like charges repel one another, opposites attract); as the particle passes the source of each field, the charge of the field is reversed so that the particle is now pushed on to another field source. Through a series of fields in sequence, the particle accelerates until it is moving at a high speed. A natural analogy to particle beams is lightning, where electrons flow from negatively charged clouds to positively charged clouds or the earth.
Low and medium energy beams are quite common. Traditional cathode ray tube televisions and computer displays use them to scan out each image, and some radiation therapy methods use them to treat cancer.
[edit] Particle beams as weapons
Though particle beams are perhaps most famously employed as weapon systems in science fiction, the U.S. Advanced Research Projects Agency started work on particle beam weapons as early as 1958 [1], two years before the first scientific demonstration of lasers. The general idea of particle-beam weaponry is to hit a target object with a stream of accelerated particles moving at near the speed of light and therefore carrying tremendous kinetic energy; the particles transfer their kinetic energy to the atoms in the molecules of the target upon striking, much as a cue ball transfers its energy to the racked balls in billiards, thus exciting the target's atoms and superheating the target object in a short time, leading to explosion either of the surface layer or the interior of the target. Currently, the materials for such weapons are "high-risk" and may not be developed for some time. [2].
The power needed to project a highly powered beam of this kind surpasses the production capabilities of any standard battlefield powerplant, thus such weapons are not anticipated to be produced in any near time. Particle beams could possibly be used from fixed locations, or in space, for example as part of the Strategic Defense Initiative (dubbed "Star Wars") or similar initiatives, but the problems related to power source still stand at present, pending future development in that field.
Particle weapons are often overlooked when compared to lasers, even though they have some advantages over their more well known counterpart.[citation needed] Because the particle beam is in fact millions of atomic-scale projectiles, there will be different issues regarding protection of targets (some particles, especially those without charge are hard to deflect or absorb). Within the atmosphere, the air would reduce the beam strength of many kinds of particles very quickly through scattering. Only actual testing will prove how effective particle beams would really be for military applications.
[edit] In Fiction
- In the game Command & Conquer: Generals, a Particle Cannon is used as the USA superweapon.
- In the X-Files Episode: Kill Switch, a particle beam fires at Fox Mulder and Dana Scully.
- Charged Particle weapons are utilised heavily in the Zoids universe. Various Zoids are equipped with Charged Particle Cannons; the Death Saurer, Geno Saurer, Geno Breaker, Death Stinger and Berserk Fury (which can fire three at once) being the most famous examples.
- In Under Siege 2: Dark Territory, starring Steven Seagal, a particle beam satellite, named Grazer One, is used as a weapon of choice by terrorists trying to extort $1 billion out of the U.S. government.
- In the Star Wars: Battlefront games, Particle cannons can be used as Particle cannon turret and in certain spaceships. A hand-held variety is also available as an unlockable sniper rifle upgrade.
- In the game Snatcher, a Phased Particle Beam is used to eradicate an important location.
- In the XBOX game Halo 2, a Particle Beam Rifle is used as a sniper rifle by The Covenant.
- In Peter F Hamilton's Commonwealth Saga series, particle beams and particle lances are part of military issue combat suits.
- The Table-top wargame Heavy Gear and both computer game adaptions feature particle cannons as a high end weapon that can only be used by large Gears and certain hovertanks.
- In the popular anime series Bubblegum Crisis, particle beam satellites were used many times as a weapon of mass destruction.
