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A '''cosmic-ray observatory''' is a scientific installation built to detect high-energy-particles coming from space called [[cosmic ray]]s. This typically includes photons (high-energy light), electrons, protons, and some heavier nuclei, as well as [[antimatter]] particles. About 90% of cosmic rays are protons, 9% are [[alpha particles]], and the rest are other particles including but not limited to lithium, beryllium and boron.<ref>[http://hyperphysics.phy-astr.gsu.edu/hbase/astro/cosmic.html C.R.Nave - '''Hyperphysics: Particles in Cosmic Rays''']</ref> About .01% of incoming cosmic rays are made of antimatter.<ref>[http://hyperphysics.phy-astr.gsu.edu/hbase/astro/cosmic.html C.R.Nave - '''Hyperphysics: Particles in Cosmic Rays''' - Quote: "According to Carroll & Ostlie, only about 0.01% of cosmic rays are antimatter, ... "]</ref>
A '''captain-ray observatory''' is a scientific installation built to detect high-energy-particles coming from space called [[cosmic ray]]s. This typically includes photons (high-energy light), electrons, protons, and some heavier nuclei, as well as [[antimatter]] particles. About 90% of cosmic rays are protons, 9% are [[alpha particles]], and the rest are other particles including but not limited to lithium, beryllium and boron.<ref>[http://hyperphysics.phy-astr.gsu.edu/hbase/astro/cosmic.html C.R.Nave - '''Hyperphysics: Particles in Cosmic Rays''']</ref> About .01% of incoming cosmic rays are made of antimatter.<ref>[http://hyperphysics.phy-astr.gsu.edu/hbase/astro/cosmic.html C.R.Nave - '''Hyperphysics: Particles in Cosmic Rays''' - Quote: "According to Carroll & Ostlie, only about 0.01% of cosmic rays are antimatter, ... "]</ref>


It is not yet possible to build [[image forming optics]] for cosmic rays, like a [[Wolter telescope]] for lower energy [[X-rays]],<ref>{{cite journal |title=Glancing Incidence Mirror Systems as Imaging Optics for X-rays |author=Wolter, H. |journal=Ann. Physik |volume=10 |pages=94 |year=1952}}</ref><ref>{{cite journal |title=A Generalized Schwarschild Mirror Systems For Use at Glancing Incidence for X-ray Imaging |author=Wolter, H. |journal=Ann. Physik |volume=10 |pages=286 |year=1952}}</ref> although some cosmic-ray observatories also look for high energy gamma rays and x-rays. [[Ultra-high-energy cosmic ray]]s (UHEC) pose further detection problems. One way of learning about cosmic rays is using different detectors to observe aspects of a cosmic ray [[Air shower (physics)|air shower]].
It is not yet possible to build [[image forming optics]] for cosmic rays, like a [[Wolter telescope]] for lower energy [[X-rays]],<ref>{{cite journal |title=Glancing Incidence Mirror Systems as Imaging Optics for X-rays |author=Wolter, H. |journal=Ann. Physik |volume=10 |pages=94 |year=1952}}</ref><ref>{{cite journal |title=A Generalized Schwarschild Mirror Systems For Use at Glancing Incidence for X-ray Imaging |author=Wolter, H. |journal=Ann. Physik |volume=10 |pages=286 |year=1952}}</ref> although some cosmic-ray observatories also look for high energy gamma rays and x-rays. [[Ultra-high-energy cosmic ray]]s (UHEC) pose further detection problems. One way of learning about cosmic rays is using different detectors to observe aspects of a cosmic ray [[Air shower (physics)|air shower]].

Revision as of 02:06, 16 August 2011

A captain-ray observatory is a scientific installation built to detect high-energy-particles coming from space called cosmic rays. This typically includes photons (high-energy light), electrons, protons, and some heavier nuclei, as well as antimatter particles. About 90% of cosmic rays are protons, 9% are alpha particles, and the rest are other particles including but not limited to lithium, beryllium and boron.[1] About .01% of incoming cosmic rays are made of antimatter.[2]

It is not yet possible to build image forming optics for cosmic rays, like a Wolter telescope for lower energy X-rays,[3][4] although some cosmic-ray observatories also look for high energy gamma rays and x-rays. Ultra-high-energy cosmic rays (UHEC) pose further detection problems. One way of learning about cosmic rays is using different detectors to observe aspects of a cosmic ray air shower.

Gamma-ray detection

Methods of detection for Gamma-rays.[5]

  • Scintillation Detectors
  • Solid State Detectors
  • Compton Scattering
  • Pair Telescopes
  • Air Cerenkov Detectors

For example, while a visible light photon may have an energy of a few eV, a cosmic gamma ray may exceed a TeV (1,000,000,000,000 eV).[5] Sometimes cosmic gamma rays (photons) are not grouped with nuclei cosmic rays.[5]

History

The Explorer 1 satellite launched in 1958 measured cosmic rays.[6] Anton 314 omnidirectional Geiger-Müller tube, designed by Dr. George Ludwig of Iowa's Cosmic Ray Laboratory, detected cosmic rays. It could detect protons with E > 30 MeV and electrons with E > 3 MeV. Most of the time the instrument was saturated;[7]

Sometimes the instrumentation would report the expected cosmic ray count (approximately thirty counts per second) but sometimes it would show a peculiar zero counts per second. The University of Iowa (under Van Allen) noted that all of the zero counts per second reports were from an altitude of 2,000+ km (1,250+ miles) over South America, while passes at 500 km (310 miles) would show the expected level of cosmic rays. Later, after Explorer 3, it was concluded that the original Geiger counter had been overwhelmed ("saturated") by strong radiation coming from a belt of charged particles trapped in space by the Earth's magnetic field. This belt of charged particles is now known as the Van Allen radiation belt.[8]

Cosmic rays were studied aboard the space station Mir in the late 20th century, such as with the SilEye experiment.[9] This studied the relationship between flashes seen by astronauts in space and cosmic rays, the cosmic ray visual phenomena.[9]

Observatories and experiments

There are a number of cosmic ray research initiatives. These include, but are not limited to:

Ultra high energy cosmic rays

Observatories for ultra-high-energy cosmic rays:

See also

References

  1. ^ C.R.Nave - Hyperphysics: Particles in Cosmic Rays
  2. ^ C.R.Nave - Hyperphysics: Particles in Cosmic Rays - Quote: "According to Carroll & Ostlie, only about 0.01% of cosmic rays are antimatter, ... "
  3. ^ Wolter, H. (1952). "Glancing Incidence Mirror Systems as Imaging Optics for X-rays". Ann. Physik. 10: 94.
  4. ^ Wolter, H. (1952). "A Generalized Schwarschild Mirror Systems For Use at Glancing Incidence for X-ray Imaging". Ann. Physik. 10: 286.
  5. ^ a b c GSFC Gamma-Ray Telescopes & Detectors
  6. ^ "Explorer-I and Jupiter-C". Data Sheet. Department of Astronautics, National Air and Space Museum, Smithsonian Institution. Retrieved 2008-02-09.
  7. ^ "Cosmic-Ray Detector". NSSDC Master Catalog. NASA. Retrieved 2008-02-09.
  8. ^ Explorer 1 (this version)
  9. ^ a b Bidoli V, et al. - Study of cosmic rays and light flashes on board Space Station MIR: the SilEye experiment.(2000) - Universita di Roma

Further reading

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