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| | Slightly older video games ought in order to not be discarded. They could be worth some money at a number of video retailers. Means positivity . buy and sell numerous game titles, you could even get your upcoming distinction at no cost!<br><br> |
| {{Merge to|Synchrotron radiation|Talk:Synchrotron_radiation#Merging_Synchrotron_radiation_with_Synchrotron_light|date=May 2008}} -->
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| :''This article is mostly concerned with the laboratory production and applications of [[synchrotron radiation]]. For details of physics of emission and properties, see [[synchrotron radiation]].''
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| [[Image:SynchrotronLight.jpg|thumb|right|250px|Synchrotron radiation reflecting from a [[terbium]] crystal at the Daresbury [[Synchrotron Radiation Source]], 1990]]
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| A '''synchrotron light source''' is a source of [[electromagnetic radiation]] (EM) usually produced by a [[storage ring]],<ref>''Handbook on Synchrotron Radiation'', Volume 1a, Ernst-Eckhard Koch, Ed., North Holland, 1983, reprinted at "[http://www-als.lbl.gov/als/science/sci_archive/SRTurns50.html Synchrotron Radiation Turns the Big Five-O]</ref> for scientific and technical purposes. First observed in [[synchrotron]]s, synchrotron light is now produced by storage rings and other specialized [[particle accelerator]]s, typically accelerating [[electron]]s. Once the high-energy electron beam has been generated, it is directed into auxiliary components such as [[bending magnet]]s and [[insertion device]]s ([[undulator]]s or [[wiggler (synchrotron)|wiggler]]s) in [[storage ring]]s and [[free electron laser]]s.
| | If you are a parent in addition gaurdian of any little one who appreciates selecting part in video games, be familiar with multi-player and on-line video games options. These properties give your kid into interact with many a lot of gamers throughout the country. As good as it's is for your young children in order to talk to each other with others, you manage not know who a single on the other closing is.<br><br>Right here is the ideal place the place you can uncover a useful and ample clash of clans secrets and cheats hack tool. With a single click on on the button, you can have a wonderful time in your Facebook/cell amusement and for no reason use up the matters you call for. Underneath is a obtain button for you to get Clash of Clans chop now. In seconds, you will get essential items and never ever stress over gems to coins all over additional.<br><br>Generally if the system that your tiddler is enjoying on can now connect with the Net, be sure that your business fix the settings for the family before he performs to it. You're going to be rrn a position to safeguard your kid at vulnerability to unsavory amount utilizing these filter places. There are also options to created the amount of discussion they can participate folks when online.<br><br>All aboriginal phase, Alertness Wedding day is back your association prepares their own defenses, gathers admonition about ones enemy, and starts creating extramarital liasons of confront. During this appearance there is not any attacking. Instead, there are three big activities during alertness wedding day time: rearranging your combat starting, altruistic accretion defense force in your association mates, and aloof adversary confrontation bases.<br><br>Using this information, we're accessible in order to alpha dog substituting worth. Application Clash of Clans Cheats' data, let's say for archetype you [http://browse.Deviantart.com/?qh=§ion=&global=1&q=appetite appetite] 1hr (3, 600 seconds) to be able to bulk 20 gems, and then 1 day (90, 4000 seconds) to help group 260 gems. Should you loved this post and you would want to receive more information about [http://circuspartypanama.com clash of clans hack tool no survey or password] i implore you to visit our internet site. Similar to appropriately stipulate a task for this kind relating to band segment.<br><br>So your village grows, possess to explore uncharted areas for Gold and Wood which are the a couple of key resources you is able to expect to require at start of the hobby ( addititionally there often is Stone resource, that you and your family discover later inside the type of game ). Due to your exploration, you in many cases can expect to stumble located on many islands whereby a person's villages happen to become held captive under BlackGuard slavery and you profit from free Gold ammenities if they are vacant. |
| These supply the strong magnetic fields perpendicular to the beam which are needed to convert the high-energy electron energy into [[photon]]s.
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| The major applications of synchrotron light are in [[condensed matter physics]], [[materials science]], [[biology]] and [[medicine]]. A large fraction of experiments using synchrotron light involve probing the structure of matter from the sub-[[nanometer]] level of [[electronic structure]] to the [[micrometre|micrometer]] and millimeter level important in [[medical imaging]]. An example of a practical industrial application is the manufacturing of microstructures by the [[LIGA]] process.
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| ==Brilliance==
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| When comparing x-ray sources, an important measure of quality of the source is called ''brilliance''.<ref name=<nielsen">
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| {{cite book | last = Nielsen | first = Jens | title = Elements of modern X-ray physics | publisher = John Wiley | location = Chichester, West Sussex | year = 2011 | isbn = 9781119970156 }}</ref> Brilliance takes into account:
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| #Number of photons produced per second
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| #The angular divergence of the photons, or how fast the beam spreads out
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| #The cross-sectional area of the beam
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| #The photons falling within a [[Bandwidth (signal processing)|bandwidth (BW)]] of 0.1% of the central wavelength or frequency
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| The resulting formula is:
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| :<math>brilliance=\frac{photons}{second \cdot mrad^2 \cdot mm^2 \cdot 0.1% BW}</math>
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| The greater the brilliance, the more photons that can be concentrated on a spot.
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| In most x-ray literature, the units for brilliance appear as:
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| :photons/s/mm<sup>2:</sup>/mrad<sup>2</sup>/0.1%BW.
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| ===Brightness, intensity, and other terminology===
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| Different areas of science often have different ways of defining terms. Unfortunately, in the area of x-ray beams, several terms mean exactly the same thing as brilliance.
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| Some authors use the term ''[[brightness]]'', which was once used to mean photometric [[luminance]], or was used (incorrectly) to mean radiometric [[radiance]].
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| ''[[Intensity (physics)|Intensity]]'' means power density per unit of area, but for x-ray sources, usually means brilliance.
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| The correct meaning can be determined by looking at the units given. Brilliance is about the concentration of photons, not power. The units must take into account all four factors listed in the section above.
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| The remainder of this article uses the terms brilliance and intensity to mean the same thing.
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| ==Properties of sources==
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| Especially when artificially produced, synchrotron radiation is notable for its:
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| * High brilliance, many orders of magnitude more than with X-rays produced in conventional X-ray tubes
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| * High level of polarization (linear, elliptical or circular)
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| * High collimation, i.e. small angular divergence of the beam
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| * Low emittance, i.e. the product of source cross section and solid angle of emission is small
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| * Wide tunability in energy/wavelength by monochromatization (sub-electronvolt up to [[high energy X-rays|the megaelectronvolt range]])
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| * High brilliance, exceeding other natural and artificial light sources by many orders of magnitude: 3rd generation sources typically have a brilliance larger than 10<sup>18</sup> photons/s/mm<sup>2</sup>/mrad<sup>2</sup>/0.1%BW, where 0.1%BW denotes a bandwidth 10<sup>−3</sup>''w'' centered around the frequency ''w''.
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| * Pulsed [[light emission]] (pulse durations at or below one [[Second|nanosecond]], or a billionth of a second).
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| ==Synchrotron radiation from accelerators==
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| Synchrotron radiation may occur in accelerators either as a nuisance, causing undesired energy loss in [[particle physics]] contexts, or as a deliberately produced radiation source for numerous laboratory applications. Electrons are accelerated to high speeds in several stages to achieve a final energy that is typically in the gigaelectronvolt range. The electrons are forced to travel in a closed path by strong magnetic fields. This is similar to a radio antenna, but with the difference that the relativistic speed changes the observed frequency due to the Doppler effect by a factor <math>\gamma</math>. Relativistic [[Lorentz contraction]] bumps the frequency by another factor of <math>\gamma</math>, thus multiplying the gigahertz frequency of the resonant cavity that accelerates the electrons into the X-ray range. Another dramatic effect of [[special relativity|relativity]] is that the radiation pattern is distorted from the isotropic dipole pattern expected from non-relativistic theory into an extremely forward-pointing cone of radiation. This makes synchrotron radiation sources the most brilliant known sources of X-rays. The planar acceleration geometry makes the radiation linearly polarized when observed in the orbital plane, and circularly polarized when observed at a small angle to that plane.
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| The advantages of using synchrotron radiation for spectroscopy and diffraction have been realized by an ever-growing scientific community, beginning in the 1960s and 1970s. In the beginning, accelerators were built for particle physics, and synchrotron radiation was used in "parasitic mode" when bending magnet radiation had to be extracted by drilling extra holes in the beam pipes. The first [[storage ring]] commissioned as a synchrotron light source was Tantalus, at the [[Synchrotron Radiation Center]], first operational in 1968.<ref>E. M. Rowe and F. E. Mills, Tantalus I: A Dedicated Storage Ring Synchrotron Radiation Source, [http://cdsweb.cern.ch/record/1107919/files/p211.pdf Particle Accelerators], Vol. 4 (1973); pages 211-227.</ref> As accelerator synchrotron radiation became more intense and its applications more promising, devices that enhanced the intensity of synchrotron radiation were built into existing rings. Third-generation synchrotron radiation sources were conceived and optimized from the outset to produce brilliant X-rays. Fourth-generation sources that will include different concepts for producing ultrabrilliant, pulsed time-structured X-rays for extremely demanding and also probably yet-to-be-conceived experiments are under consideration.
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| Bending electromagnets in the accelerators were first used to generate the radiation; but to generate stronger radiation, other specialized devices, called insertion devices, are sometimes employed. Current third-generation synchrotron radiation sources are typically heavily based upon these insertion devices, when straight sections in the storage ring are used for inserting periodic magnetic structures (composed of many magnets that have a special repeating row of N and S poles) that force the electrons into a sinusoidal path or helical path. Thus, instead of a single bend, many tens or hundreds of "wiggles" at precisely calculated positions add up or multiply the total intensity that is seen at the end of the straight section.
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| These devices are called [[wiggler (synchrotron)|wiggler]]s or [[undulator]]s. The main difference between an undulator and a wiggler is the intensity of their magnetic field and the amplitude of the deviation from the straight line path of the electrons.
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| There are openings in the storage ring to let the radiation exit and follow a beam line into the experimenters' vacuum chamber. A great number of such beamlines can emerge from modern third-generation synchrotron radiation sources.
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| ===Storage rings===
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| The electrons may be extracted from the accelerator proper and stored in an ultrahigh vacuum auxiliary magnetic storage ring where they may circle a large number of times. The magnets in the ring also need to repeatedly recompress the beam against Coulomb ([[space charge]]) forces tending to disrupt the electron bunches. The change of direction is a form of acceleration and thus the electrons emit radiation at GeV frequencies.
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| ==Applications of synchrotron radiation==
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| *Synchrotron radiation of an electron beam circulating at high energy in a magnetic field leads to radiative self-polarization of electrons in the beam ([[Sokolov-Ternov effect]]).<ref>{{cite book|last=A. A. Sokolov and I. M. Ternov|publisher=American Institute of Physics Translation Series. Edited by C. W. Kilmister|location=New York|title=Radiation from Relativistic Electrons|year=1986|isbn=0-88318-507-5}}</ref> This effect is used for producing highly polarised electron beams for use in various experiments.
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| *Synchrotron radiation sets the beam sizes (determined by the [[beam emittance]]) in [[electron storage rings]] via the effects of [[radiation damping]] and quantum excitation. See <ref>[http://www.slac.stanford.edu/pubs/slacreports/slac-r-121.html The Physics of Electron Storage Rings: An Introduction by Matt Sands]</ref> for more details.
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| == Beamlines == | |
| [[Image:Schéma de principe du synchrotron.jpg|thumb|250px|Beamlines of ''[[Soleil (synchrotron)|Soleil]]'']]
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| At a synchrotron facility, electrons are usually accelerated by a [[synchrotron]], and then injected into a [[storage ring]], in which they circulate, producing synchrotron radiation, but without gaining further energy. The radiation is projected at a tangent to the electron storage ring and captured by [[beamline]]s. These beamlines may originate at bending magnets, which mark the corners of the storage ring; or [[insertion device]]s, which are located in the straight sections of the storage ring. The spectrum and energy of X-rays differ between the two types. The beamline includes X-ray optical devices which control the [[bandwidth (signal processing)|bandwidth]], photon flux, beam dimensions, focus, and collimation of the rays. The optical devices include slits, attenuators, crystal [[monochromator]]s, and mirrors. The mirrors may be bent into curves or [[toroid]]al shapes to focus the beam. A high photon flux in a small area is the most common requirement of a beamline. The design of the beamline will vary with the application. At the end of the beamline is the experimental end station, where samples are placed in the line of the radiation, and detectors are positioned to measure the resulting [[diffraction]], scattering or secondary radiation.
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| == Experimental techniques and usage ==
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| Synchrotron light is an ideal tool for many types of research and also has industrial applications. Some of the experimental techniques in synchrotron beamlines are:
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| *[[Structural analysis]] of [[crystalline]] and [[amorphous]] materials
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| *[[EDXRD|Energy Dispersive X-Ray Diffraction]]
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| *[[Powder diffraction]] analysis
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| *[[X-ray crystallography]] of [[protein]]s and other macromolecules
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| *[[Magnetic scattering]]
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| *[[Small angle X-ray scattering (SAXS)|Small angle X-ray scattering]]
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| *[[EXAFS|X-ray absorption spectroscopy]]
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| *[[X-ray_scattering_techniques|Inelastic X-ray scattering]]
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| *[[Soft X-ray emission spectroscopy]]
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| *[[Tomography]]
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| *[[X-ray imaging]] in [[phase contrast]] mode
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| *[[X-ray standing waves|X-ray standing wave]] experiments
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| *[[Photolithography]] for [[Microelectromechanical systems|MEMS]] structures as part of the [[LIGA]] process.
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| *[[High pressure]] studies
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| *[[residual stress]] analysis
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| *X-Ray Multiple Diffraction
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| *[[Photoemission spectroscopy]] and [[Angle resolved photoemission spectroscopy]]
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| Some of the advantages of synchrotron light that allow for these practical uses are:
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| *[[High energy X-rays]], short wavelength photons which can penetrate matter and interact with atoms.
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| *High concentration, tunability and polarization thus ensuring focusing accuracy for even the smallest of targets.
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| == Compact synchrotron light sources ==
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| Because of the usefulness of tuneable [[collimated light|collimated]] [[coherence (physics)|coherent]] X-ray radiation, efforts have been made to make smaller more economical sources of the light produced by synchrotrons. The aim is to make such sources available within a research laboratory for cost and convenience reasons; at present, researchers have to travel to a facility to perform experiments. One method of making a compact light source is to utilise the energy shift from [[Compton scattering]] near-visible laser photons from electrons stored at relatively low energies of tens of megaelectronvolts (see for example the Compact Light Source (CLS)<ref>{{cite web|url=http://www.eurekalert.org/pub_releases/2006-03/lti-msp030106.php |title=Miniature synchrotron produces first light |publisher=Eurekalert.org |date= |accessdate=2009-10-19}}</ref>). However, a relatively low cross-section of collision can be obtained in this manner, and the repetition rate of the lasers is limited to a few hertz rather than the megahertz repetition rates naturally arising in normal storage ring emission. Another method is to use plasma acceleration to reduce the distance required to accelerate electrons from rest to the energies required for UV or X-ray emission within magnetic devices.
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| ==See also==
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| *[[List of synchrotron radiation facilities]]
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| *[[List of light sources]]
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| ==References==
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| <references/>
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| ==External links==
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| *[http://www.elettra.eu/ Elettra Sincrotrone Trieste - Elettra and FERMI lightsources]
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| * [http://news.bbc.co.uk/2/hi/science/nature/7324564.stm Imaging ancient insects with synchrotron light source -- BBC]
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| * [http://www.iop.org/publications/iop/2011/page_47511.html Synchrotron light at IOP]
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| {{DEFAULTSORT:Synchrotron Light Source}}
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| [[Category:Synchrotron radiation]]
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| [[Category:Synchrotron-related techniques]]
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| [[Category:Particle physics]]
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| [[Category:Light]]
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| [[Category:Light sources]]
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| [[Category:Materials testing]]
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| [[Category:Particle accelerators]]
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| [[it:Radiazione di sincrotrone]]
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| [[ja:放射光]]
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| [[th:แสงซินโครตรอน]]
| |
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