Synchrotron

:This article is concerned with the synchrotron device - a sub-atomic particle accelerator. For applications of the synchrotron radiation produced by cyclic particle accelerators see synchrotron light.

Related Topics:
Synchrotron radiation - Synchrotron light

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A synchrotron is a particular type of cyclic particle accelerator in which the magnetic field (to turn the particles so they circulate) and the electric field (to accelerate the particles) are carefully synchronized with the travelling particle beam. While a cyclotron uses a constant magnetic field and a constant-frequency applied electric field, and one of these is varied in the synchrocyclotron, both of these are varied in the synchrotron. By increasing these parameters appropriately as the particles gain energy, their path can be held constant as they are accelerated. This allows the vacuum container for the particles to be a large thin torus (commonly described as a "doughnut shape"). In reality it is easier to use some straight sections and some bent sections giving the "doughnut shape" the shape of a rounded cornered polygon. A path of large effective radius may thus be constructed using simple straight and curved pipe segments, unlike the disc-shaped chamber of the cyclotron type devices. The shape also allows and requires the use of multiple magnets to bend the particle beam.

Related Topics:
Particle accelerator - Cyclotron - Synchrocyclotron - Parameter - Torus

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The maximum energy that a cyclic accelerator can impart is typically limited by the strength of the magnetic field(s) and the maximum radius of the particle path.

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In a cyclotron the maximum radius is quite limited as the particles start at the center and spiral outward, thus this entire path must be a self-supporting disc-shaped evacuated chamber. Since the radius is limited, the power of the machine becomes limited by the strength of the magnetic field. In the case of an ordinary (not superconducting) electromagnet the field strength is limited by the saturation of the core (when all magnetic domains are aligned the field may not be further increased to any practical extent). The arrangement of the single pair of magnets the full width of the device also limits the economic size of the device.

Related Topics:
Superconducting - Electromagnet

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Synchrotrons overcome these limitations, allowing a narrow beam pipe which can be surrounded by much smaller and more tightly focused magnets. The ability of this device to accelerate particles is limited by the fact that the particles must be charged to be accelerated at all, but charged particles under acceleration emit photons (light), thereby losing energy. The limiting beam energy is reached when the energy lost to the lateral acceleration required to maintain the beam path in a circle equals the energy added each cycle. More powerful accelerators are built by using large radius paths and by using more numerous and more powerful microwave cavities to accelerate the particle beam between corners. Lighter particles (such as electrons) lose a larger fraction of their energy when turning. Practically speaking, the energy of electron/positron accelerators is limited by this radiation loss, while it does not play a significant role in the dynamics

Related Topics:
Light - Microwave cavities - Electron - Positron

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of proton or ion accelerators. The energy of those is limited strictly by the

Related Topics:
Proton - Ion

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strength of magnets and by the cost.

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One of the early large synchrotrons, now retired, is the Bevatron, constructed in 1950 at the Lawrence Berkeley Laboratory. The name of this proton accelerator comes from its power, in the range of 6.3 GeV (then called BeV for billion electron volts; the name predates the adoption of the SI prefix giga). A number of heavy elements, unseen in the natural world, were first created with this machine. This site is also the location of one of the first large bubble chambers used to examine the results of the atomic collisions produced here.

Related Topics:
Bevatron - Lawrence Berkeley Laboratory - Proton - GeV - Electron volt - SI prefix - Giga - Bubble chamber

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Currently, the highest energy synchrotron in the world is the Tevatron, at the Fermi National Accelerator Laboratory, in the United States. It accelerates protons and antiprotons to nearly 1 TeV of kinetic energy and collides them together. The Large Hadron Collider (LHC), which is being built

Related Topics:
Tevatron - Fermi National Accelerator Laboratory - United States - Protons - Antiprotons - TeV - Large Hadron Collider - LHC

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at the Eurpoean Laboratory for High Energy Physics (CERN), will have roughly seven times this energy, and is scheduled to turn on in 2007. It is being built in the 27 km tunnel which formerly housed the Large Electron Positron (LEP) collider, so it will maintain the claim as the largest scientific device ever built.

Related Topics:
CERN - LEP

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The largest device of this type yet seriously proposed was the Superconducting Super Collider (SSC), to be built in the United States. This design uses superconducting magnets which allow more intense magnetic fields to be created without the limitations of core saturation. While construction was begun, the project was cancelled in 1994, citing excessive budget overruns — this was due to naive cost estimation and economic management issues rather than any basic engineering flaws. It can also be argued that the end of the Cold War resulted in a

Related Topics:
Superconducting Super Collider - United States - Superconducting - Cold War

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change of scientific funding priorities that contributed to its ultimate cancellation.

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While there is still potential for yet more powerful proton and heavy particle cyclic accelerators, it appears that the next step up in electron acceleration power must avoid losses due to synchrotron radiation.

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This will require a return to the linear accelerator, but with devices significantly longer than those currently in use. There is a present a major effort to design and build the International Linear Collider (ILC), which will consist of two opposing linear accelerators, one for

Related Topics:
Linear accelerator - International Linear Collider - ILC - Linear accelerators

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electrons and one for positrons. These will collide at a total center of mass energy of 500 GeV.

Related Topics:
Center of mass energy - GeV

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However many scientists use synchrotron radiation (see synchrotron light) and for them the production of synchrotron radiation is the only purpose of a synchrotron.

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Synchrotron radiation is useful for a wide range of applications and many synchrotrons have been built especially to produce synchrotron light. SPring-8 in Japan is one of them, providing the world's most powerful (as of 2005) electron acceleration capacity of 8 GeV.

Related Topics:
SPring-8 - Japan - 2005

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