Collider
Encyclopedia
A collider is a type of a particle accelerator
involving directed beams of particles
.
Colliders may either be ring accelerators or linear accelerators.
one gains knowledge about elementary particle
s by accelerating particles to very high kinetic energy
and letting them impact on other particles. For sufficiently high energy, a reaction
happens that transforms the particles into other particles. Detecting these products gives insight into the physics
involved.
To do such experiments there are two possible setups:
The collider setup is harder to construct but has the great advantage that according to special relativity
the energy of an inelastic collision
between two particles approaching each other with a given velocity is not just 4 times as high as in the case of one particle resting (as it would be in non-relativistic physics); it can be orders of magnitude higher if the collision velocity is near the speed of light.
rings Tihiro Ohkawa, one of the authors of the first paper, went on to develop a radial-sector FFAG accelerator design that could accelerate two counterrotating particle beams within a single ring of magnets. The third FFAG prototype built by the MURA group was a 50 MeV electron machine built in 1961 to demonstrate the feasibility of this concept.
Gerard K. O'Neill proposed using a single accelerator to inject particles into a pair of tangent storage ring
s. As in the original MURA proposal, collisions would occur in the tangent section. The benefit of storage rings is that the storage ring can accumulate a high beam flux from an injection accelerator that achieves a much lower flux.
The first electron
-positron
colliders were built in Italy, at the Frascati
laboratories near Rome, by the Austrian-Italian physicist Bruno Touschek
. Around the same time, in the early 1960s, the VEP-1 collider was independently developed and built under supervision of Gersh Budker
in the Soviet Institute of Nuclear Physics
.
In 1966, work began on the Intersecting Storage Rings
at CERN
, and in 1971, this collider was operational. The ISR was a pair of storage rings that accumulated particles injected by the CERN Proton Synchrotron
. This was the first hadron
collider, as all of the earlier efforts had worked with electrons or with electrons and positrons.
Particle accelerator
A particle accelerator is a device that uses electromagnetic fields to propel charged particles to high speeds and to contain them in well-defined beams. An ordinary CRT television set is a simple form of accelerator. There are two basic types: electrostatic and oscillating field accelerators.In...
involving directed beams of particles
Elementary particle
In particle physics, an elementary particle or fundamental particle is a particle not known to have substructure; that is, it is not known to be made up of smaller particles. If an elementary particle truly has no substructure, then it is one of the basic building blocks of the universe from which...
.
Colliders may either be ring accelerators or linear accelerators.
Explanation
In particle physicsParticle physics
Particle physics is a branch of physics that studies the existence and interactions of particles that are the constituents of what is usually referred to as matter or radiation. In current understanding, particles are excitations of quantum fields and interact following their dynamics...
one gains knowledge about elementary particle
Elementary particle
In particle physics, an elementary particle or fundamental particle is a particle not known to have substructure; that is, it is not known to be made up of smaller particles. If an elementary particle truly has no substructure, then it is one of the basic building blocks of the universe from which...
s by accelerating particles to very high kinetic energy
Kinetic energy
The kinetic energy of an object is the energy which it possesses due to its motion.It is defined as the work needed to accelerate a body of a given mass from rest to its stated velocity. Having gained this energy during its acceleration, the body maintains this kinetic energy unless its speed changes...
and letting them impact on other particles. For sufficiently high energy, a reaction
Nuclear reaction
In nuclear physics and nuclear chemistry, a nuclear reaction is semantically considered to be the process in which two nuclei, or else a nucleus of an atom and a subatomic particle from outside the atom, collide to produce products different from the initial particles...
happens that transforms the particles into other particles. Detecting these products gives insight into the physics
Physics
Physics is a natural science that involves the study of matter and its motion through spacetime, along with related concepts such as energy and force. More broadly, it is the general analysis of nature, conducted in order to understand how the universe behaves.Physics is one of the oldest academic...
involved.
To do such experiments there are two possible setups:
- Fixed target setup: A beam of particles (the projectiles) is accelerated with a particle acceleratorParticle acceleratorA particle accelerator is a device that uses electromagnetic fields to propel charged particles to high speeds and to contain them in well-defined beams. An ordinary CRT television set is a simple form of accelerator. There are two basic types: electrostatic and oscillating field accelerators.In...
, and as collision partner, one puts a stationary target into the path of the beam.
- Collider: Two beams of particles are accelerated and the beams are directed against each other, so that the particles collide while flying in opposite directions. This process can be used to make strange and anti-matter.
The collider setup is harder to construct but has the great advantage that according to special relativity
Special relativity
Special relativity is the physical theory of measurement in an inertial frame of reference proposed in 1905 by Albert Einstein in the paper "On the Electrodynamics of Moving Bodies".It generalizes Galileo's...
the energy of an inelastic collision
Inelastic collision
An inelastic collision, in contrast to an elastic collision, is a collision in which kinetic energy is not conserved.In collisions of macroscopic bodies, some kinetic energy is turned into vibrational energy of the atoms, causing a heating effect, and the bodies are deformed.The molecules of a gas...
between two particles approaching each other with a given velocity is not just 4 times as high as in the case of one particle resting (as it would be in non-relativistic physics); it can be orders of magnitude higher if the collision velocity is near the speed of light.
History
The first serious proposal for a collider originated with a group at the Midwestern Universities Research Association (MURA). This group proposed building two tangent radial-sector FFAG acceleratorFFAG accelerator
A Fixed-Field Alternating Gradient accelerator is a type of circular particle accelerator being developed for potential applications in physics, medicine, national security, and energy production, that has features of cyclotrons and synchrotrons...
rings Tihiro Ohkawa, one of the authors of the first paper, went on to develop a radial-sector FFAG accelerator design that could accelerate two counterrotating particle beams within a single ring of magnets. The third FFAG prototype built by the MURA group was a 50 MeV electron machine built in 1961 to demonstrate the feasibility of this concept.
Gerard K. O'Neill proposed using a single accelerator to inject particles into a pair of tangent storage ring
Storage ring
A storage ring is a type of circular particle accelerator in which a continuous or pulsed particle beam may be kept circulating for a long period of time, up to many hours. Storage of a particular particle depends upon the mass, energy and usually charge of the particle being stored...
s. As in the original MURA proposal, collisions would occur in the tangent section. The benefit of storage rings is that the storage ring can accumulate a high beam flux from an injection accelerator that achieves a much lower flux.
The first electron
Electron
The electron is a subatomic particle with a negative elementary electric charge. It has no known components or substructure; in other words, it is generally thought to be an elementary particle. An electron has a mass that is approximately 1/1836 that of the proton...
-positron
Positron
The positron or antielectron is the antiparticle or the antimatter counterpart of the electron. The positron has an electric charge of +1e, a spin of ½, and has the same mass as an electron...
colliders were built in Italy, at the Frascati
Frascati
Frascati is a town and comune in the province of Rome in the Lazio region of central Italy. It is located south-east of Rome, on the Alban Hills close to the ancient city of Tusculum. Frascati is closely associated with science, being the location of several international scientific...
laboratories near Rome, by the Austrian-Italian physicist Bruno Touschek
Bruno Touschek
Bruno Touschek was an Austrian physicist, a survivor of the Holocaust, and initiator of research on electron-positron colliders.-Biography:...
. Around the same time, in the early 1960s, the VEP-1 collider was independently developed and built under supervision of Gersh Budker
Gersh Budker
Gersh Itskovich Budker , also named Alexander Mikhailovich Budker, was a Soviet nuclear physicist....
in the Soviet Institute of Nuclear Physics
Budker Institute of Nuclear Physics
The Budker Institute of Nuclear Physics is one of the major centres of advanced study of nuclear physics in Russia. It is located in the Siberian town Akademgorodok, on Academician Lavrentiev Avenue. The institute was founded by Gersh Itskovich Budker in 1959...
.
In 1966, work began on the Intersecting Storage Rings
Intersecting Storage Rings
The ISR was a particle accelerator at CERN. It was the world's first hadron collider, and ran from 1971 to 1984, with a maximum center of mass energy of 62 GeV...
at CERN
CERN
The European Organization for Nuclear Research , known as CERN , is an international organization whose purpose is to operate the world's largest particle physics laboratory, which is situated in the northwest suburbs of Geneva on the Franco–Swiss border...
, and in 1971, this collider was operational. The ISR was a pair of storage rings that accumulated particles injected by the CERN Proton Synchrotron
Proton Synchrotron
The Proton Synchrotron is the first major particle accelerator at CERN, built as a 28 GeV proton accelerator in the late 1950s and put into operation in 1959. It takes the protons from the Proton Synchrotron Booster at a kinetic energy of 1.4 GeV and lead ions from the Low Energy Ion Ring at 72...
. This was the first hadron
Hadron
In particle physics, a hadron is a composite particle made of quarks held together by the strong force...
collider, as all of the earlier efforts had worked with electrons or with electrons and positrons.
See also
- Large Electron–Positron Collider
- Large Hadron ColliderLarge Hadron ColliderThe Large Hadron Collider is the world's largest and highest-energy particle accelerator. It is expected to address some of the most fundamental questions of physics, advancing the understanding of the deepest laws of nature....
- Very Large Hadron ColliderVery Large Hadron ColliderThe Very Large Hadron Collider is a name for a hypothetical future hadron collider with performance significantly beyond the Large Hadron Collider....
- Relativistic Heavy Ion ColliderRelativistic Heavy Ion ColliderThe Relativistic Heavy Ion Collider is one of two existing heavy-ion colliders, and the only spin-polarized proton collider in the world. It is located at Brookhaven National Laboratory in Upton, New York and operated by an international team of researchers...
- International Linear ColliderInternational Linear ColliderThe International Linear Collider is a proposed linear particle accelerator. It is planned to have a collision energy of 500 GeV initially, and, if approved after the project has published its Technical Design Report, planned for 2012, could be completed in the late 2010s. A later upgrade to 1000...
- Storage ringStorage ringA storage ring is a type of circular particle accelerator in which a continuous or pulsed particle beam may be kept circulating for a long period of time, up to many hours. Storage of a particular particle depends upon the mass, energy and usually charge of the particle being stored...
- TevatronTevatronThe Tevatron is a circular particle accelerator in the United States, at the Fermi National Accelerator Laboratory , just east of Batavia, Illinois, and is the second highest energy particle collider in the world after the Large Hadron Collider...