Difference between revisions 1286672 and 1325029 on enwikiversity

[[Image:Detectors summary 3.png|thumb|right|200px|This tree diagram shows the relationship between types and classification of most common particle detectors. Credit: [[commons:User:Wdcf|Wdcf]].]]
'''Radiation detectors''' provide a signal that is converted to an electric current. The device is designed so that the current provided is proportional to the characteristics of the incident radiation.
{{experimental}}
There are detectors that provide a change in substance as the signal and these may be automated to provide an electric current or quantified proportional to the amount of new substance.
{{article}}
{{lecture}}
{{astronomy}}
{{Materials science}}
{{physics}}
{{technologyclear}}

=[[Astronomy]]=

A detector in [[radiation astronomy]] may need to be able to separate a collection of incoming radiation to obtain a clear set of signals for the radiation of interest. For example, a detector designed for [[red astronomy]] may need to be on the rocky-object surface of the [[Earth]] to separate X-rays and gamma-rays from red rays.

=[[Radiation]]=

'''Def.''' an action or process of throwing or sending out a traveling ray in a line, beam, or stream of small cross section is called '''radiation'''.

"Radiation may affect materials and devices in deleterious ways:"<ref name=RadiationDamage>{{ cite web
|title=Radiation damage, In: ''Wikipedia''
|publisher=Wikimedia Foundation, Inc
|location=San Francisco, California
(contracted; show full)|publisher=Wikimedia Foundation, Inc
|location=San Francisco, California
|month=May 8,
|year=2013
|url=http://en.wikipedia.org/wiki/Radiation_hardening
|accessdate=2013-05-24 }}</ref>

=
[[Planetary science]]=
[[Image:Ash and Steam Plume, Soufriere Hills Volcano, Montserrat.jpg|thumb|right|200px|This oblique astronaut photograph from the International Space Station (ISS) captures a white-to-grey ash and steam plume extending westwards from the Soufriere Hills volcano. Credit: NASA Expedition 21 crew.]]
(contracted; show full)|publisher=Wikimedia Foundation, Inc
|location=San Francisco, California
|month=May 15,
|year=2013
|url=http://en.wikipedia.org/wiki/Detector_(radio)
|accessdate=2013-05-25 }}</ref> is called a '''detector'''.

'''Def.''' “[a] device capable of registering a specific substance or physical phenomenon”<ref name=Detector
Wikt>{{ cite web
|title=detector, In: ''Wiktionary''
|publisher=Wikimedia Foundation, Inc
|location=San Francisco, California
|month=May 30,
|year=2012
|url=http://en.wiktionary.org/wiki/detector
|accessdate=2012-06-19 }}</ref> is called a '''detector'''.
(contracted; show full)e dead time was less than 20%. Based on a log-histogram of the time intervals between events, the dead-time has been estimated to a fractional accuracy of better than 5%. We determine the photopeak efficiency by comparing the dead-time corrected event rate in the photopeak with the theoretical expectation assuming a perfect detector."<ref name=Krawczynski/>

'''Def.''' "the average energy loss of the particle per unit path length"<ref name=StoppingPower
ParticleRadiation>{{ cite web
|title=Stopping power (particle radiation), In: ''Wikipedia''
|publisher=Wikimedia Foundation, Inc
|location=San Francisco, California
|month=May 8April 11,
|year=2013
|url=http://en.wikipedia.org/wiki/Stopping_power_(particle_radiation)
|accessdate=2013-05-244-11 }}</ref> is called the '''stopping power'''.

'''Def.''' "the slowing down of a projectile ion due to the inelastic collisions between bound electrons in the medium and the ion moving through it"<ref name=StoppingPowerParticleRadiation/> is called the '''electronic stopping power'''.

'''Def.''' "the elastic collisions between the projectile ion and atoms in the sample ... [involving] the interaction of the ion with the ''nuclei'' in the target"<ref name=StoppingPowerParticleRadiation/> is called the '''nuclear stopping power'''.

=Sources=

"[T]he hardware setup also defines key experimental parameters, such as source-detector distance, solid angle and detector shielding."<ref name=NeutronDetection>{{ cite web
|title=Neutron detection, In: ''Wikipedia''
|publisher=Wikimedia Foundation, Inc
|location=San Francisco, California
(contracted; show full) of [[w:frequency|frequency]] or [[w:wavelength|wavelength]], due to its interaction with a sample. The sample absorbs energy, i.e., photons, from the radiating field. The intensity of the absorption varies as a function of frequency, and this variation is the [[w:Absorption spectroscopy#Absorption spectrum|absorption spectrum]]. Absorption spectroscopy is performed across the [[w:electromagnetic spectrum|electromagnetic spectrum]]."<ref name=AbsorptionSpectroscopy>{{ cite web
|title=Absorption 
aspectroscopy, In: ''Wikipedia''
|publisher=Wikimedia Foundation, Inc
|location=San Francisco, California
|month=March 13,
|year=2013
|url=http://en.wikipedia.org/wiki/Absorption_spectroscopy
|accessdate=2013-05-22 }}</ref>

(contracted; show full)|journal=Microelectronics Reliability
|volume=40
|issue=11
|month=November
|year=2000
|pages=1833&ndash;37
|publisher=Elsevier
|doi=10.1016/S0026-2714(00)00063-9 }}</ref> which needs steep potential barrier) or manufacturing quality and semiconductor defects, such as conductance fluctuations, including [[w:1/f noise|1/f noise]]."<ref name=NoiseElectronics>{{ cite 
journalweb
|title=Noise (electronics)⏎
|journal=, In: ''Wikipedia''
|publisher=Wikimedia Foundation, Inc
|location=San Francisco, California
|month=March 12,
|year=2013
|url=http://en.wikipedia.org/wiki/Noise_(electronics)
|pdf=⏎
|accessdate=2013-05-24 }}</ref>

"[N]oise is an error or undesired random disturbance of a useful information signal, introduced before or after the detector and decoder. The noise is a summation of unwanted or disturbing energy from natural and sometimes man-made sources. Noise is, however, typically distinguished from interference, (e.g. cross-talk, deliberate jamming or other unwanted electromagnetic interference from specific transmitters), for example in the signal-to-noise ratio (SNR), sign(contracted; show full)

In the image at right, a 0.3 m meteor has impacted a ''meteor detector'', in this case the [[Moon]], and created a scintillation event that in turn is detected by a photoelectronic detector system.

In the image at left, a meteor has impacted another detector, here [[Jupiter]], but instead of a scintillation event has created a lowering of albedo as detected by the photoelectronic system, the Hubble Space Telescope.

=Cosmic-ray
s=
[[Image:Cloud chamber bionerd.jpg|thumb|right|200px|Cloud chamber shows visible tracks from α-particles (short, thick) and β-particles (long, thin). Credit: Bionerd.]]
[[Image:Electronic nuclear stopping Al in Al.png|thumb|right|200px|Diagram shows the electronic and nuclear stopping power for aluminum ions in aluminum. Credit: HPaul.]]
[[Image:Ion slowing.png|thumb|right|200px|This is an ilustration of the slowing down of a single ion in a solid material. Credit: Kai Nordlund.]]
(contracted; show full)
|author=Samuel Ting, Manuel Aguilar-Benitez, Silvie Rosier, Roberto Battiston, Shih-Chang Lee, Stefan Schael, and Martin Pohl
|title=Alpha Magnetic Spectrometer - 02 (AMS-02)
|publisher=NASA
|location=Washington, DC USA
|month=April 13,
|year=2013
|url=http://www.nasa.gov/mission_pages/station/research/experiments/742.html

|pdf=⏎
|accessdate=2013-05-17 }}</ref>

The second figure on the right shows the electronic and nuclear stopping power of aluminum single crystal for aluminum ions. These stopping powers are versus particle energy per nucleon. The maximum of the nuclear stopping curve typically occurs at energies of the order of 1 keV per nucleon.

The third figure at right illustrates the slowing down of a single ion in a solid material.

"In the beginning of the slowing-down process at high energies, the ion is slowed down mainly by electronic stopping, and it moves almost in a straight path. When the ion has slowed down sufficiently, the collisions with nuclei (the nuclear stopping) become more and more probable, finally dominating the slowing down. When atoms of the solid receive significant recoil energies when struck by the ion, they will be removed from their [[w:crystal structure|lattice]] positions, and produce a [[w:collision cascade|cascade of further collisions]] in the material. These 
[[w:collision cascade|collision cascade]]s are the main cause of damage production during ion implantation in metals and semiconductors."<ref name=StoppingPowerParticleRadiation/>

"When the energies of all atoms in the system have fallen below the [[w:threshold displacement energy|threshold displacement energy]], the production of new damage ceases, and the concept of nuclear stopping is no longer meaningful. The total amount of energy deposited by the nuclear collisions to atoms in the materials is called the nuclear deposited energy."<ref name=StoppingPowerParticleRadiation/>

"The inset in the figure shows a typical range distribution of ions deposited in the solid. The case shown here might for instance be the slowing down of a 1 MeV silicon ion in silicon. The mean range for a 1 MeV ion is typically in the micrometer range."<ref name=StoppingPowerParticleRadiation/>

Fourth right is an illustration of a ''Bragg'' curve. The '''stopping power''' and hence, the density of ionization, usually increases toward the end of range and reaches a maximum, the Bragg peak, shortly before the energy drops to zero.
{{clear}}

=Neutrons=

(contracted; show full)|title=Compound semiconductor radiation detectors
|journal=Nuclear Instruments and Methods in Physical Research A
|month=September
|year=2004
|volume=531
|issue=1-2
|pages=18-37
|url=http://www.
sciencedirect.com/science/article/pii/S0168900204010575
|arxiv=
|bibcode=
|doi=10.1016/j.nima.2004.05.071
|pmid=
|pdf=http://www.msri.org/people/staff/levy/files/ToPrint/owens-compound.pdf
|arxiv=
|bibcode=
|doi=10.1016/j.nima.2004.05.071
|pmid=⏎
|accessdate=2013-05-24 }}</ref>
{{clear}}

=Electrons=
[[Image:Galileo Energetic Particles Detector.jpg|thumb|right|200px|This is an image of the Energetic Particles Detector (EPD) aboard the Galileo Orbiter. Credit: NASA.]]
(contracted; show full)
|author=Donald J. Williams
|title=Energetic Particles Detector (EPD)
|publisher=NASA Goddard Space Flight Center
|location=Greenbelt, Maryland USA
|month=May 14,
|year=2012
|url=http://nssdc.gsfc.nasa.gov/nmc/experimentDisplay.do?id=1989-084B-06

|pdf=⏎
|accessdate=2012-08-11 }}</ref>
{{clear}}

=Positrons=

"In the first 18 months of operations, AMS-02 [image under Cherenkov detectors] recorded 6.8 million positron (an antimatter particle with the mass of an electron but a positive charge) and electron events produced from cosmic ray collisions with the interstellar medium in the energy range between 0.5 giga-electron volt (GeV) and 350 GeV. These events were used to determine the positron fraction, the ratio of positrons to the total number of(contracted; show full)|issue=7
|pages=4475-9
|url=http://prd.aps.org/abstract/PRD/v55/i7/p4475_1
|arxiv=astro-ph/9608201
|bibcode=1997PhRvD..55.4475H
|doi=10.1103/PhysRevD.55.4475
|pmid=

|pdf=⏎
|accessdate=2013-01-18 }}</ref>
{{clear}}

=Neutrinos=
[[Image:Sudbury neutrino observatory.png|thumb|right|200px|The Sudbury Neutrino Observatory, a 12-meter sphere filled with heavy water surrounded by light detectors located 2000 meters below the ground in Sudbury, Ontario, Canada. Credit: NASA.]]
(contracted; show full)|issue=12
|pages=8
|url=http://prb.aps.org/abstract/PRB/v84/i12/e125203
|arxiv=
|bibcode=
|doi=10.1103/PhysRevB.84.125203
|pmid=

|pdf=⏎
|accessdate=2013-05-24 }}</ref>

=Violets=
[[Image:Voyager - Filters - Violet.png|thumb|right|200px|The image shows the spectral range for the violet filter of Voyager 1 and Voyager 2. Credit: [[commons:User:Xession|Xession]].]]
Most spacecraft designed for [[optical astronomy]] or [[visual astronomy]] carry aboard a violet or blue filter covering the wavelength range from 350-430 nm. The Solid State Imaging camera of the Galileo spacecraft uses a broad-band filter centered at 404 nm for [[violet astronomy]].

The Hubble Space Telescope has throughout its long life used a variety of violet broad and narrow band filters for violet astronomy. The Wide Field Planetary Camera (PC-1) in use from about 1990 through 1993 carried the violet band filters: F330W, F336W, F344N, F368M, F375N, F413M, F435W, F437N, F439W, and F469N. The Wide Field Planetary Camera (PC-2) replaced PC-1 and carried the following violet filters on the same filter wheels: F300W, F336W, F343N, F375N, F380W, F390N, F410M, F437N, F439W, F450W, F467M and F469N.

The violet filter on each of the Viking Orbiters is centered at 440 nm with a range of 350-470 nm.

At right is an image of the spectral range of the Violet filter (50 to 400 nm)<ref name=Benesh>{{ cite web
|author=M. Benesh and F. Jepsen
|title=SP-474 Voyager 1 and 2 Atlas of Six Saturnian Satellites Appendix A The Voyager Mission
|publisher=NASA
|location=Washington, DC USA
|month=August 6,
|year=1984
|url=http://history.nasa.gov/SP-474/appa.htm
|pdf=⏎
|accessdate=2013-04-01 }}</ref> on the Imaging Science System aboard the Voyager 1 and Voyager 2 Spacecraft, as defined by the instrument descriptions of the Narrow Angle Camera and Wide Angle Camera.
{{clear}}

=Blues=

In about 1981 "an efficient blue- and violet-sensitive RCA CCD did appear on the market."<ref name=Oke>{{ cite journal
|author=J. B. Oke and J. E. Gunn
|title=An Efficient Low Resolution and Moderate Resolution Spectrograph for the Hale Telescope
|journal=Publications of the Astronomical Society of the Pacific
|month=June
|year=1982
|volume=94
|issue=06
|pages=586-94
|url=
|arxiv=
|bibcode=1982PASP...94..586O
|doi=10.1086/131027
|pmid=
|pdf=⏎
|accessdate=2013-05-24 }}</ref>

"To allow for the maximum number of high-efficiency coatings it was decided to separate the light into two separate spectrographs using a dichroic filter located immediately behind the entrance aperture of slit. The dichroic, mounter at 45°, reflects blue and violet light and transmits red and near-infrared light."<ref name=Oke/>

The blue- and violet-sensitive CCD successfully detected the helium lines from 501.5 to 318.8 nm.<ref name=Oke/>

"The MIC (Microchannel plate Intensified CCD (Charge Coupled Device)) detector ... [has a] measured resolution of the detector system [of] 18 micrometers FWHM at 490 nm. [It is] for the ESA X-Ray Multi Mirror Mission (XMM), where the MIC has been accepted as the blue detector for the incorporated Optical Monitor (OM)."<ref name=Thomsen>{{ cite book
|author=J. L. A. Fordham, D. A. Bone, M. K. Oldfield, J. G. Bellis, and T. J. Norton
|title=The MIC photon counting detector, In: ''Proceedings of an ESA Symposium on Photon Detectors for Space Instrumentation''
|publisher=European Space Agency
|location=
|month=December
|year=1992
|editor=
|pages=103-6
|url=
|arxiv=
|bibcode=1992ESASP.356..103F
|doi=
|pmid=
|isbn=
|pdf=⏎
|accessdate=2013-05-24 }}</ref>

"A0620-00 [is observed] with the [Faint Object Spectrograph] FOS blue detector" while aboard the Hubble Space Telescope.<ref name=McClintock>{{ cite book
|author=Jeffrey McClintock
|title=Black Hole A0620-00 and Advection-Dominated Accretion, In: ''HST Proposal ID #7393''
|publisher=STSci
|location=Baltimore, Maryland USA
|month=December
|year=1997
|editor=
|pages=
|url=
|arxiv=
|bibcode=1997hst..prop.7393M
|doi=
|pmid=
|isbn=
|pdf=⏎
|accessdate=2013-05-24 }}</ref>

=Cyans=

The Wide Field/Planetary Camera (PC-1) had an F469N, F487N, and F492M cyan filters in the filter wheel.<ref name=Krist/>

The Wide Field Planetary Camera (PC-2) replaced PC-1 on the Hubble Space Telescope and carried the following cyan filters on the same filter wheels: F467M, F469N, F487N.<ref name=Krist>{{ cite web
|author=John Krist and Richard Hook
|title=The Tiny Tim User’s Guide, Version 6.3
|publisher=Space Telescope Science Institute
|location=
|month=June
|year=2004
|url=http://www.stsci.edu/software/tinytim
|pdf=⏎
|accessdate=2013-01-22 }}</ref>

The Advanced Camera for Surveys carried an F475W broadband cyan filter.<ref name=Krist/>

The Faint Object Camera (FOC) carries F470M, F480LP, and F486N cyan filters.<ref name=Krist/>

=Greens=

The Wide Field Planetary Camera (PC-1) of the Hubble Space Telescope was in use from about 1990 through 1993. It carried 48 filters on 12 filter wheels of four each. For the green band, these were the F492M, F502N, F517N, F547M, and the F555W. Those ending in 'N' are narrow-band filters.<ref name=Krist>{{ cite web
|author=John Krist and Richard Hook
|title=The Tiny Tim User’s Guide, Version 6.3
|publisher=Space Telescope Science Institute
|location=
|month=June
|year=2004
|url=http://www.stsci.edu/software/tinytim
|pdf=http://tinytim.stsci.edu/static/tinytim.pdf
|accessdate=2013-01-22 }}</ref>

One of these filters is F492M which allows imaging with the [O III]λλ4959,5007 and its adjacent green continuum. The filter band pass is centered at 490.6 nm with a full-width at half maximum (FWHM) of 36.4 nm.<ref name=Wilson>{{ cite journal
|author=A. S. Wilson, J. A. Braatz, T. M. Heckman, J. H. Krolik, and G. K. Miley
|title=The Ionization Cones in the Seyfert Galaxy NGC 5728
|journal=The Astrophysical Journal Letters
|month=December 20,
|year=1993
|volume=419
|issue=12
|pages=L61-4
|url=
|arxiv=
|bibcode=1993ApJ...419L..61W
|doi=10.1086/187137
|pmid=
|pdf=⏎
|accessdate=2013-01-21 }}</ref>

"The F492M filter also includes H''β''.<ref name=Wilson/>

The F502N is centered at 501.85 nm with a band pass of 2.97 nm. The F547M is centered at 546.1 nm with a band pass of 43.8 nm.

(contracted; show full)| deadurl= no}}</ref>"<ref name=AstronomicalFilter>{{ cite web
|title=Astronomical filter, In: ''Wikipedia''
|publisher=Wikimedia Foundation, Inc
|location=San Francisco, California
|month=25 January
|year=2013
|url=http://en.wikipedia.org/wiki/Astronomical_filter

|pdf=⏎
|accessdate=2013-01-25 }}</ref>

Initially the Hubble Space Telescope had the Wide Field/Planetary Camera (WF/PC-1) aboard where the F555W, F569W, F588N, and F606W cover the entire yellow portion of the electromagnetic spectrum.

The Hubble's Faint Object Camera (FOC) uses F550M and F600M which cover from either side.

The Wide Field and Planetary Camera (WFPC2) replaced PC-1 and used F555W, F569W, F588N and F606W filters.

(contracted; show full)
|title=Ultra-low power hydrogen sensing based on a palladium-coated nanomechanical beam resonator
|author=Jonas Henriksson
|journal=Nanoscale Journal
|accessdate=2013-02-26 }}</ref>"<ref name=HydrogenSensor>{{ cite 
journalweb
|title=Hydrogen sensor⏎
|journal=, In: ''Wikipedia''
|publisher=Wikimedia Foundation, Inc
|location=San Francisco, California
|month=March 16,
|year=2013
|url=http://en.wikipedia.org/wiki/Hydrogen_sensor
|pdf=⏎
|accessdate=2013-05-26 }}</ref>

=Liquid objects=
[[Image:Hot and cold water immiscibility thermal image.jpg|thumb|right|200px|Thermal image of a sink full of hot water with cold water being added shows the hot and the cold water flowing into each other. Credit: [[commons:User:Zaereth|Zaereth]].]]
(contracted; show full)
|author=JHU/APL
|title=Mercury Shows Its True Colors
|publisher=JHU/APL
|location=Baltimore, Maryland USA
|month=January 30,
|year=2008
|url=http://messenger.jhuapl.edu/gallery/sciencePhotos/image.php?page=1&gallery_id=2&image_id=143

|pdf=⏎
|accessdate=2013-04-01 }}</ref>

The object at left is detected to be a rocky object using [[radar astronomy]].

"The advantages of radar in planetary astronomy result from (1) the observer's control of all the attributes of the coherent signal used to illuminate the target, especially the wave form's time/frequency modulation and polarization; (2) the ability of radar to resolve objects spatially via measurements of the distribution of echo power in time delay and Doppler frequency; (3) the pronounced degree to which delay-Doppler measurements constrain orbits and spin vectors; and (4) centimeter-to-meter wavelengths, which easily penetrate optically opaque planetary clouds and cometary comae, permit investigation of near-surface macrostructure and bulk density, and are sensitive to high concentrations of metal or, in certain situations, ice."<ref name=Ostro>{{ cite journal
|author=Steven J. Ostro
|title=Planetary radar astronomy
|journal=Reviews of Modern Physics
|month=October-December
|year=1993
|volume=65
|issue=4
|pages=1235-79
|url=http://rmp.aps.org/abstract/RMP/v65/i4/p1235_1
|arxiv=
|bibcode=
|doi=10.1103/RevModPhys.65.1235
|pmid=
|pdf=⏎
|accessdate=2012-02-09 }}</ref>

=Astrochemistry=
[[Image:XRFScan.jpg|thumb|right|200px|Typical energy dispersive XRF spectrum for a number of elements is shown. Credit: [[w:User:LinguisticDemographer|LinguisticDemographer]].]]
(contracted; show full)
|title=''Submillimeter Wave Astronomy Satellite'' Observations of the Martian Atmosphere: Temperature and Vertical Distribution of Water Vapor
|journal=The Astrophysical Journal
|month=August 20,
|year=2000
|volume=539
|issue=2
|pages=L143-6
|url=http://iopscience.iop.org/1538-4357/539/2/L143
/pdf/1538-4357_539_2_L143.pdf
|arxiv=
|bibcode=
|doi=
|pmid=
|pdf=http://iopscience.iop.org/1538-4357/539/2/L143/pdf/1538-4357_539_2_L143.pdf⏎
|accessdate=2012-08-04 }}</ref>

=Alloys=

"A metal detector is a device which responds to metal that may not be readily apparent. The simplest form of a metal detector consists of an oscillator producing an alternating current that passes through a coil producing an alternating magnetic field. If a piece of electrically conductive metal is close to the coil, eddy currents will be induced in the metal, and this produces a magnetic field of its own. If another coil is used to measure the magnetic (contracted; show full)rent would flow in the metal, and the time for the voltage to drop to zero would be increased. These time differences were minute, but the improvement in electronics made it possible to measure them accurately and identify the presence of metal at a reasonable distance. These new machines had one major advantage: they were completely impervious to the effects of mineralization, and rings and other jewelry could now be located even under highly-mineralized black sand."<ref name=MetalDetector/>

=
[[Sun (star)|Sun]]=

"A ''sun sensor'' is a device that senses the direction to the [[Sun (star)|Sun]]. This can be as simple as some [[w:solar cell|solar cell]]s and shades, or as complex as a steerable [[w:telescope|telescope]], depending on mission requirements."<ref name=AttitudeControl/>

=[[Earth]]=

"An ''earth sensor'' is a device that senses the direction to the [[Earth]]. It is usually an infrared camera; now the main method to detect attitude is the star tracker, but earth sensors are still integrated in satellites for their low cost and reliability."<ref name=AttitudeControl/>

=Stars=

(contracted; show full)) and then filtered to remove problematic stars, for example due to [[w:apparent magnitude|apparent magnitude]] variability, [[w:color index|color index]] uncertainty, or a location within the [[w:Hertzsprung-Russell diagram|Hertzsprung-Russell diagram]] implying unreliability. These types of star catalogs can have thousands of stars stored in memory on board the spacecraft, or else processed using tools at the [[w:ground station|ground station]] and then uploaded."<ref name=AttitudeControl/>

=
[[Geography]]=

Occasionally, a detector needs a specific geographic property for optimal function.

==Large surface area==
[[Image:PierreAugerObservatory DetectorComponents.jpg|thumb|200px|right|Surface detector station and AERA radio antenna is in the foreground, one of the four fluorescence detector buildings and the three HEAT telescopes is in the background. Credit: [[commons:User:Tobias Winchen|Tobias Winchen]].]]
“The '''Pierre Auger Observatory''' is an international cosmic ray observatory designed to detect [[w:ultra-high-energy cosmic ray|ultra-high-energy cosmic ray]]s: single [[w:sub-atomic particle|sub-atomic particle]]s ([[w:proton|proton]]s or [[w:Atomic nucleus|atomic nuclei]]) with energies beyond 10<sup>20</sup>&nbsp;[[w:electronvolt|eV]] (about the energy of a [[w:tennis ball|tennis ball]] traveling at 80&nbsp;km/h). These high energy particles have an estimated arrival rate of just 1 per km<sup>2</sup> per century, therefore the Auger Observatory has created a detection area the size of [[w:Rhode Island|Rhode Island]] — over 3,000 km<sup>2</sup> (1,200 sq mi) — in order to record a large number of these events. It is located in western [[w:Argentina|Argentina]]'s [[w:Mendoza Province|Mendoza Province]], in one of the South American [[w:Pampas|Pampas]].”<ref name=PierreAugerObservatory>{{ cite web
|title=Pierre Auger Observatory, In: ''Wikipedia''
|publisher=Wikimedia Foundation, Inc
|location=San Francisco, California
|month=May 16,
|year=2013
|url=http://en.wikipedia.org/wiki/Pierre_Auger_Observatory
|accessdate=2013-05-17 }}</ref/>
{{clear}}

==Next to water==
[[Image:Old dome of the Big Bear Solar Observatory (Big Bear Lake, California).jpg|thumb|right|200px|The old dome on the main BBSO building is viewed from Big Bear Lake. Credit: [[w:User:Magi Media|Magi Media]].]]
(contracted; show full)|publisher=Wikimedia Foundation, Inc
|location=San Francisco, California
|month=July 4,
|year=2012
|url=http://en.wikipedia.org/wiki/ANTARES_(telescope)
|accessdate=2012-08-23 }}</ref>

=
[[History]]=
[[Image:Oso5 wheel.gif|thumb|left|200px|The figure of the OSO 5 wheel contains detectors for gamma-rays, X-rays, ultraviolet, and visible (Zodiacal light). Credit: HEASARC, NASA.]]
[[Image:Oso5 NRLxrd.gif|thumb|right|The diagram of the Naval Research Laboratory Solar X-ray Radiation Ion Chamber Photometer shows the location of the center crystal. Credit: NASA.]]
(contracted; show full)
|author=Heasarc
|title=OSO-5
|publisher=NASA GSFC
|location=Greenbelt, Maryland USA
|month=June 26,
|year=2003
|url=http://heasarc.gsfc.nasa.gov/docs/heasarc/missions/oso5.html

|pdf=⏎
|accessdate=2013-05-18 }}</ref>
{{clear}}

=[[Mathematics]]=

"The energy differences between levels in the Bohr model, and hence the wavelengths of emitted/absorbed photons, is given by the Rydberg formula<ref name=Bohr>{{ citation
|author=Niels Bohr
|chapter=Rydberg's discovery of the spectral laws
|editor=J. Kalckar
|title=N. Bohr: Collected Works
|publisher=North-Holland Publ.
|location=Amsterdam
|year=1985
|volume=10
|pages=373–9 }}</ref>:

:<math> {1 \over \lambda} = R \left( {1 \over (n^\prime)^2} - {1 \over n^2} \right) \qquad \left( R = 1.097373 \times 10^7 \ \mathrm{m}^{-1} \right)</math>
where ''n'' is the initial energy level, ''n&prime;'' is the final energy level, and ''R'' is the [[w:Rydberg constant|Rydberg constant]]. Meaningful values are returned only when ''n'' is greater than ''n&prime;'' and the limit of one over infinity is taken to be zero."<ref name=Hydrogenspectral>{{ cite web
|title=Hydrogen spectral series, In: ''Wikipedia''
|publisher=Wikimedia Foundation, Inc
|location=San Francisco, California
|month=May 2,
|year=2012
|url=http://en.wikipedia.org/wiki/Hydrogen_spectral_series
|accessdate=2012-05-14 }}</ref>

=[[Physics]]=
"A [[w:relativistic jet|relativistic jet]] coming out of the center of an [[w:active galactic nucleus|active galactic nucleus]] is moving along AB with a velocity v. We are observing the jet from the point O. At time <math>t_1</math> a light ray leaves the jet from point A and another ray leaves at time <math>t_2</math> from point B. Observer at O receives the rays at time <math>t_1^\prime</math> and <math>t_2^\prime</math> respectively."<ref na(contracted; show full)  | publisher = IEEE
  | location = 
  | year = 1994
  | url = 
  | doi = 10.1109/23.322831
  | id =  |bibcode = 1994ITNS...41..915M }}</ref>”<ref name=NeutronDetector/>

=Silicon drift detector
s=

"Silicon drift detectors (SDDs), produced by conventional semiconductor fabrication, now provide a cost-effective and high resolving power radiation measurement. Unlike conventional X-ray detectors, such as Si(Li)s, they do not need to be cooled with liquid nitrogen."<ref name=XRayDetector/>

=Scintillator plus semiconductor detectors=

(contracted; show full)nverted to a voltage and then a digital signal, which is interpreted by a computer to produce a digital image. Although silicon has outstanding electronic properties, it is not a particularly good absorber of X-ray photons. For this reason, X-rays first impinge upon scintillators made from such materials as gadolinium oxysulfide or caesium iodide. The scintillator absorbs the X-rays and converts them into visible light photons that then pass onto the photodiode array."<ref name=XRayDetector/>

=
[[Research]]=

==Hypothesis:
# Radiation detectors can be built to differentiate between superluminal, luminal, and subluminal radiations.

==[[Proof of concept]]==

'''Def.''' a “short and/or incomplete [[wikt:realization|realization]] of a certain [[wikt:method|method]] or idea to demonstrate its feasibility"<ref name=ProofofConceptWikt>{{ cite web
|title=proof of concept, In: ''Wiktionary''
|publisher=Wikimedia Foundation, Inc
|location=San Francisco, California
|month=November 10,
|year=2012
|url=http://en.wiktionary.org/wiki/proof_of_concept
|accessdate=2013-01-13 }}</ref> is called a '''proof of concept'''.

'''Def.''' evidence that demonstrates that a concept is possible is called '''proof of concept'''.

The proof-of-concept structure consists of
# background,
# procedures,
# findings, and
# interpretation.<ref name=Lehrman>{{ cite journal
|author=Ginger Lehrman and Ian B Hogue, Sarah Palmer, Cheryl Jennings, Celsa A Spina, Ann Wiegand, Alan L Landay, Robert W Coombs, Douglas D Richman, John W Mellors, John M Coffin, Ronald J Bosch, David M Margolis
|title=Depletion of latent HIV-1 infection in vivo: a proof-of-concept study
|journal=Lancet
|month=August 13,
|year=2005
|volume=366
|issue=9485
|pages=549-55
|url=http://www.sciencedirect.com/science/article/pii/S0140673605670985ncbi.nlm.nih.gov/pmc/articles/PMC1894952/
|arxiv=
|bibcode=
|doi=10.1016/S0140-6736(05)67098-5
|pmid=
|pdf=http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1894952/⏎
|accessdate=2012-05-09 }}</ref>

Proof of concept for a radiation detector is that the radiation characteristics are accurately reported. This requires standards of performance and standard radiation sources.

==[[Control groups]]==
[[Image:Lewis rat.jpg|thumb|right|200px|This is an image of a Lewis rat. Credit: Charles River Laboratories.]]
The findings demonstrate a statistically systematic change from the status quo or the [[control group]].

“In the design of experiments, treatments [or special properties or characteristics] are applied to [or observed in] experimental units in the '''treatment group'''(s).<ref name=Hinkelmann>{{ cite book
|author=Klaus Hinkelmann, Oscar Kempthorne
|year=2008
(contracted; show full)<!-- categories -->
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