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| '''Particle physics experiments''' briefly discusses a number of past, present, and proposed experiments with particle accelerators, throughout the world. In addition, some important accelerator interactions are discussed. Also, some notable systems components are discussed, named by project.
| | Search, complete presell pages, I do not know to join and you will make money online have to promote. We are going to find what works for you. If the survey sites are free if you have to be a very interesting, but for me.<br><br>Also visit my web blog [http://www.warriorforum.com/warrior-forum-classified-ads/987380-google-sniper-truth.html google sniper free download] |
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| ==AEGIS (particle physics)==
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| '''AEGIS''' is a proposed experiment to be set up at the [[Antiproton Decelerator]] at [[CERN]]. In addition, ''AEGIS'' is an acronym for: '''A'''ntimatter '''E'''xperiment: '''G'''ravity, '''I'''nterferometry, '''S'''pectroscopy)
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| '''The proposed experiment:'''
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| It would attempt to determine if [[gravity]] affects [[antimatter]] in the same way it affects [[matter]] by testing its effect on an [[antihydrogen]] beam. By sending a stream of antihydrogen through a series of [[diffraction grating]]s, the pattern of light and dark patterns would allegedly enable the position of the beam to be pinpointed with up to 1% accuracy.<ref>
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| {{cite web
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| | last = Courtland | first = R.
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| | date=12 June 2008
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| | title = Would an antimatter apple fall up?
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| | url = http://space.newscientist.com/article/dn14120-would-an-antimatter-apple-fall-up.html?DCMP=ILC-hmts&nsref=news1_head_dn14120
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| | work = [[New Scientist]]
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| | accessdate = 2008-10-27
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| }}</ref>
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| ==Athena==
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| {{two other uses|the CERN project|the Greek goddess|Athena|other uses|Athena (disambiguation)}}
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| '''ATHENA''' was an [[antimatter]] research project that took place at the AD Ring at [[CERN]]. In 2005 ATHENA was disbanded and many of the former members became the [[ALPHA Collaboration]]. In August 2002, it was the first experiment to produce 50,000 low-energy antihydrogen atoms, as reported in the journal [[Nature (journal)|Nature]].<ref>
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| {{cite press
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| |date=19 September 2002
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| |title=Thousands of cold anti-atoms produced at CERN
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| |url=http://press.web.cern.ch/press/PressReleases/Releases2002/PR09.02Eantihydrogen.html
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| |publisher=[[CERN]]
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| |accessdate=2012-04-10
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| }}</ref><ref>
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| {{cite journal
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| |last1=Amoretti |first1=M.
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| |coauthors=''et al.''
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| |year=2002
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| |title=Production and detection of cold antihydrogen atoms
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| |journal=[[Nature (journal)|Nature]]
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| |volume=419 |issue=6906 |pages=456
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| |bibcode=2002Natur.419..456A
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| |doi=10.1038/nature01096
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| |pmid=12368849
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| }}</ref>
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| For [[antihydrogen]] to be created, [[antiproton]]s and [[positron]]s must first be prepared. Once the antihydrogen is created, a high-resolution detector is needed to confirm that the antihydrogen was created, as well as to look at the spectrum of the antihydrogen in order to compare it to "normal" hydrogen.<ref>
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| {{cite web
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| |date=14 September 2002
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| |title=How the ATHENA Experiment works
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| |url=http://athena-positrons.web.cern.ch/ATHENA-positrons/wwwathena/overview.html
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| |publisher=[[ATHENA]]
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| |accessdate=2012-04-10
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| }}</ref>
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| The antiprotons are obtained from CERN's Antiproton Decelerator while the positrons are obtained from a [[positron accumulator]]. The antiparticles are then led into a recombination trap to create antihydrogen. The trap is surrounded by the ATHENA detector, which detects the annihilation of the antiprotons as well as the positrons.
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| The ATHENA Collaboration comprised the following institutions<ref>
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| {{cite web
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| |date=30 January 2006
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| |title=The ATHENA Collaboration
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| |url=http://athena-positrons.web.cern.ch/ATHENA-positrons/wwwathena/collaboration.html
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| |publisher=[[ATHENA]]
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| |accessdate=2012-04-10
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| }}</ref>
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| * [[University of Aarhus]], [[Denmark]]
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| * [[University of Brescia]], [[Italy]]
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| * [[CERN]]
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| * [[University of Genoa]], Italy
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| * [[University of Pavia]], Italy
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| * [[RIKEN]], Japan
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| * [[Federal University of Rio de Janeiro]], Brazil
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| * [[University of Wales Swansea]], [[United Kingdom]]
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| * [[University of Tokyo]], [[Japan]]
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| * [[University of Zurich]], [[Switzerland]]
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| * [[INFN|National Institute for Nuclear Physics]], Italy
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| ==ARGUS (experiment)==
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| {{about|the particle physics experiment|nuclear weapons tests|Operation Argus}}
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| The '''ARGUS''' experiment was a [[particle physics]] experiment that ran at the electron-positron collider ring ''DORIS II'' at [[DESY]]. It is the first experiment that observed the mixing of the [[B meson]]s (in 1987)<ref>
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| {{cite journal
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| |last1=Albrecht |first1=H.
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| |coauthors=''et al.'' (ARGUS Collaboration)
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| |year=1987
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| |title=Observation of B<sup>0</sup>–{{overline|B}}<sup>0</sup> mixing
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| |journal=[[Physics Letters B]]
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| |volume=192 |issue=1–2 |pages=245
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| |bibcode=1987PhLB..192..245A
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| |doi=10.1016/0370-2693(87)91177-4
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| }}</ref>
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| The ARGUS detector was a [[hermetic detector]] with 90% coverage of the full solid angle. It had [[drift chamber]]s, a time-of-flight system, an electromagnetic [[Calorimeter (particle physics)|calorimeter]] and a muon chamber system.<ref>
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| {{cite journal
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| |last1=Albrecht |first=H.
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| |coauthors=''et al.'' (ARGUS Collaboration)
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| |year=1989
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| |title=Argus: A universal detector at DORIS II
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| |journal=[[Nuclear Instruments and Methods in Physics Research Section A]]
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| |volume=275 |issue=1 |pages=1–48
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| |bibcode=1989NIMPA.275....1A
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| |doi=10.1016/0168-9002(89)90334-3
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| }}</ref>
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| In [[physics]], the '''[[ARGUS distribution]]''', named after this experiment,<ref>{{cite journal
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| |last1=Albretch |first=H.
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| |coauthors=''et al.'' (ARGUS Collaboration)
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| |year=1990
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| |title=Search for hadronic b→u decays
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| |journal=[[Physics Letters B]]
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| |volume=241 |issue=2 |pages=278
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| |bibcode=1990PhLB..241..278A
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| |doi=10.1016/0370-2693(90)91293-K
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| }} The function has been defined with parameter ''c'' representing the beam energy and parameter ''p'' set to 0.5. The normalization and the parameter χ have been obtained from data.</ref> is the [[probability distribution]] of the reconstructed invariant mass of a decayed particle candidate in continuum background. Its [[probability density function]] (not normalized) is:
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| : <math>f(x)=x\cdot\sqrt{1-\left(\frac{x}{c}\right)^2}\exp\left\{-\chi\cdot\left(1-\left(\frac{x}{c}\right)^2\right)\right\}\text{ for }x>0.</math>
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| Sometimes a more general form is used to describe a more peaking-like distribution:
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| : <math>f(x)=x\cdot\left[1-\left(\frac{x}{c}\right)^2\right]^p\exp\left\{-\chi\cdot\left(1-\left(\frac{x}{c}\right)^2\right)\right\}</math>
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| Here parameters ''c'', χ, ''p'' represent the cutoff, curvature, and power (''p'' = 0.5 gives a regular ARGUS) respectively.
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| ==ATRAP==
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| [http://hussle.harvard.edu/~atrap/ The '''ATRAP''' collaboration] at [[CERN]] developed out of TRAP, a collaboration whose members pioneered cold [[antiproton]]s, cold [[positron]]s, and first made the ingredients of cold [[antihydrogen]] to interact. ATRAP members also pioneered accurate [[hydrogen]] [[spectroscopy]] and first observed hot antihydrogen atoms. The collaboration includes investigators from [[Harvard]], the [[University of Bonn]], the [[Max Planck Institute for Quantum Optics]], the [[University of Amsterdam]], [[York University]], [[Seoul National University]], [[NIST]], [[Forschungszentrum Jülich]].
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| ==Belle experiment==
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| {{main|Belle experiment}}
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| The '''Belle experiment''' is a [[particle physics]] experiment conducted by the Belle Collaboration, an international collaboration of more than 400 physicists and engineers investigating [[CP-violation]] effects at the High Energy Accelerator Research Organisation ([[KEK]]) in [[Tsukuba]], [[Ibaraki Prefecture]], [[Japan]].
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| ==Systems components==
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| ===ASTRID particle storage ring===
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| '''ASTRID''' is a particle [[storage ring]] at the [[University of Aarhus]], [[Århus]], [[Denmark]]. It is located in the lower levels of the University of Aarhus Department of Physics and Astronomy.
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| Its construction was announced on 18 September 1987.<ref>
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| {{cite journal
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| |last1=Stensgaard |first1=R.
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| |year=1988
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| |title=ASTRID - The Aarhus Storage Ring
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| |journal=[[Physica Scripta]]
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| |volume=1988 |issue=T22 |pages=315
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| |bibcode=1988PhST...22..315S
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| |doi=10.1088/0031-8949/1988/T22/051
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| }}</ref> By 1998, it had been improved several times, notably increasing its maximum operation time to 30–35 hours.<ref>
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| {{cite journal
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| |last1=Nielsen |first1=J. S.
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| |last2=Møller |first2=S. P.
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| |year=1998
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| |title=New Developments at the ASTRID storage ring
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| |url=http://accelconf.web.cern.ch/AccelConf/e98/PAPERS/WEP05F.PDF
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| |journal=Proceedings from 6th European Particle Accelerator Conference
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| |accessdate=2012-04-10
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| }}</ref> In December 2008, a contract was awarded to design and build [[ASTRID 2 particle storage ring|ASTRID 2]], which will be built adjacent to ASTRID.
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| ASTRID will be used to "top up" the new ring, allowing ASTRID 2 to operate nearly continuously.<ref name=astrid2>
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| {{cite web
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| |title=ASTRID2 – the ultimate synchrotron radiation source
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| |url=http://www.isa.au.dk/facilities/astrid2/astrid2.asp
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| |publisher=[[ASTRID]]
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| |accessdate=2012-04-10
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| }}</ref>
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| ====ASTRID 2 particle storage ring====
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| '''ASTRID 2''' will be a 46 meter particle [[storage ring]] at the [[University of Aarhus]], [[Århus]], [[Denmark]].The contract to build the ring was awarded in December, 2008, and plans are expected to be complete by the end of 2009. It will be built in the lower levels of the University of Aarhus Department of Physics and Astronomy, adjacent to the existing [[ASTRID particle storage ring]]. Rather than having an electron beam which decays over time, it will be continually "topped up" by a feed from ASTRID, allowing nearly constant current.<ref name="astrid2"/> It will generate [[synchrotron radiation]] to provide a tunable [[synchrotron light source|beam of light]], expected to be of "remarkable" quality, with wavelengths from the ultraviolet through x-rays.<ref name=astrid2 />
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| ===Anti-proton deccelerator===
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| The '''Antiproton Decelerator''' (AD) is a [[storage ring]] at the [[CERN]] laboratory in [[Geneva]]. The decelerated [[antiproton]]s are ejected to one of the connected experiments.
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| '''Current experiments'''
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| {|
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| ! Expt. !! Acronym !! Full name
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| |-
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| | AD-2 || [[ATRAP]] || Anti-hydrogen Trap Collaboration
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| |-
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| | AD-3 || ASACUSA || Atomic Spectroscopy And Collisions Using Slow Anti-protons
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| |-
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| | AD-4 || ACE ||Anti-proton Cell Experiment
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| |-
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| | AD-5 || ALPHA || Anti-hydrogen Laser Physics Apparatus
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| |-
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| | AD-6 || AEGIS || Anti-hydrogen Experiment: Gravity, Interferometry, Spectroscopy
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| |}
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| '''Former experiments:'''
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| {|
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| ! Expt. !! Acronym !! Full name
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| |-
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| | AD-1 || [[ATHENA]] || ApparaTus for High-precision Experiments on Neutral Antimatter
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| |}
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| ==Accelerator interaction overview==
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| ===Absorber===
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| In [[Particle physics|high energy physics]] experiments, an '''absorber''' is a block of material used to [[adsorption|absorb]] some of the energy of an incident [[Elementary particle|particle]]. Absorbers can be made of a variety of materials, depending on the purpose; [[lead]] and [[liquid hydrogen]] are common choices.
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| Most absorbers are used as part of a [[detector]].
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| A more recent use for absorbers is for [[ionization cooling]], as in the [[International Muon Ionization Cooling Experiment]].
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| In [[solar power]], the most important part of the collector takes up the heat of the [[Sun|solar]] [[radiation]] through a medium (water + [[antifreeze]]). This is heated and circulates between the collector and the storage tank. A high degree of efficiency is achieved by using black absorbers or, even better, through selective coating.
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| In [[sunscreen]], ingredients which absorb UVA/UVB rays, such as [[avobenzone]] and [[octyl methoxycinnamate]], are known as absorbers. They are contrasted with physical "blockers" of UV radiation such as [[titanium dioxide]] and [[zinc oxide]].
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| ===Accelerator physics===
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| {{main|Accelerator physics}}
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| '''Accelerator physics''' is an [[interdisciplinary]] topic of [[applied physics]], commonly defined by the intent of designing, building and operating [[particle accelerator]]s.
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| The experiments conducted with particle accelerators are not regarded as part of accelerator physics, but belong (according to the objectives of the experiments) to e.g. [[particle physics]], [[nuclear physics]], [[condensed matter physics]] or [[materials physics]]. The types of experiments done at a particular accelerator facility are determined by characteristics of the generated [[particle beam]] such as average energy, particle type, intensity, and dimensions.
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| ===Event reconstruction===
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| {{Main|Event reconstruction}}
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| In a [[particle detector]] experiment, [[event (particle physics)|event]] '''reconstruction''' is the process of interpreting the [[Electronics|electronic]] signals produced by the detector to determine the original [[Elementary particle|particle]]s that passed through, their momenta, directions, and the primary [[vertex (physics)|vertex]] of the event. Thus the initial physical process that occurred at the [[interaction point]] of the [[particle accelerator]], whose study is the ultimate goal of the experiment, can be determined. The total event reconstruction is rarely possible (and rarely necessary); usually, only some part of the data described above is obtained and processed.
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| ==See also==
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| *[[ALPHA Collaboration]]
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| *[[Antimatter]]
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| *[[CERN]]
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| *[[List of synchrotron radiation facilities]]
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| *[[Gravitational interaction of antimatter]]
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| *[[Particle physics]]
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| ==References==
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| {{reflist}}
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| ==Further reading==
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| * {{cite web
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| |author=AEGIS collaboration
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| |date=8 June 2007
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| |title=Proposal for the AEGIS experiment at the CERN Antiproton Decelerator
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| |url=http://doc.cern.ch//archive/electronic/cern/preprints/spsc/public/spsc-2007-017.pdf
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| |publisher=[[CERN]]
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| }}
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| *{{cite journal
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| |last1= Testera|first1=G.
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| |coauthors=''et al.''
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| |year=2008
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| |title = Formation of a cold antihydrogen beam in AEGIS for gravity measurements
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| |journal=[[AIP Conference Proceedings]]
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| |volume=1037 |pages=5–15
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| |arxiv=0805.4727
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| |bibcode=2008AIPC.1037....5T
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| |doi =10.1063/1.2977857
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| }}
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| ==External links==
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| {{Wiktionary}}
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| *[http://www.ansto.gov.au/index.html ANSTO website]
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| *[http://old-www.ansto.gov.au/natfac/antares.html ANTARES website]
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| *[http://psdoc.web.cern.ch/PSdoc/acc/ad/index.html Antiproton Decelerator website]
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| *[http://argus-fest.desy.de/introduction.html ARGUS Fest]
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| *[http://www.isa.au.dk/facilities/astrid/astrid.html ASTRID website]
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| *[http://www.isa.au.dk/facilities/astrid2/astrid2.html ASTRID 2 website]
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| *[http://athena.web.cern.ch/athena ATHENA website]
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| *[http://public.web.cern.ch/Public/Welcome.html CERN's public site]
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| *[http://livefromcern.web.cern.ch/livefromcern/antimatter/factory/AM-factory01.html CERN Antimatter page]
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| *[http://old-www.ansto.gov.au/ari/facility/cyc.html National Medical Cyclotron website]
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| [[Category:Particle experiments]]
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| [[Category:Research projects]]
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| [[hu:Antiproton Decelerator]]
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| [[ru:Абсорбер]]
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| [[sl:Absorber]]
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| [[tk:Absorber]]
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