Geiger counter
A modern geiger counter
Other names	Geiger-Müller counter
Uses	Particle detector
Inventor	Hans Geiger
Related items	Geiger-Müller tube
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A Geiger counter, also called a Geiger-Müller counter, is a type of particle detector that measures ionizing radiation. In experimental and applied Particle physics and Nuclear engineering, a particle detector, also known as a radiation detector, is a device used to Johannes (Hans Wilhelm Geiger ( September 30, 1882 &ndash September 24, 1945) was a German Physicist. A Geiger-Müller tube (or GM tube) is the sensing element of a Geiger counter instrument that can detect a single particle of Ionizing radiation, and typically In experimental and applied Particle physics and Nuclear engineering, a particle detector, also known as a radiation detector, is a device used to Image talkNew_radiation_symbol_ISO_21482svg for details --> Ionizing radiation

Description

Geiger counters are used to detect radiation, usually alpha and beta radiation, but certain models can also detect gamma radiation as well. Radiation, as in Physics, is Energy in the form of waves or moving Subatomic particles emitted by an atom or other body as it changes from a higher energy Alpha decay is a type of radioactive decay in which an Atomic nucleus emits an Alpha particle (two protons and two neutrons bound together into a particle Beta particles are high-energy high-speed Electrons or Positrons emitted by certain types of Radioactive nuclei such as Potassium -40 Gamma rays (denoted as &gamma) are a form of Electromagnetic radiation or light emission of frequencies produced by sub-atomic particle interactions The sensor is a Geiger-Müller tube, an inert gas-filled tube (usually helium, neon or argon with halogens added) that briefly conducts electricity when a particle or photon of radiation temporarily makes the gas conductive. A Geiger-Müller tube (or GM tube) is the sensing element of a Geiger counter instrument that can detect a single particle of Ionizing radiation, and typically Helium ( He) is a colorless odorless tasteless non-toxic Inert Monatomic Chemical Neon (ˈniːɒn is the Chemical element that has the symbol Ne and Atomic number 10 This article pertains to the chemical element For other uses see Argon (disambiguation. Abundance Owing to their high Reactivity, the halogens are found in the environment only in compounds or as Ions Halide ions and oxoanions In Particle physics, an elementary particle or fundamental particle is a particle not known to have substructure that is it is not known to be made In Physics, the photon is the Elementary particle responsible for electromagnetic phenomena The tube amplifies this conduction by a cascade effect and outputs a current pulse, which is then often displayed by a needle or lamp and/or audible clicks. An electron avalanche is a process in which a number of Free electrons in a medium (usually a Gas) are subjected to strong acceleration by an Electric Modern instruments can report radioactivity over several orders of magnitude. Some Geiger counters can also be used to detect gamma radiation, though sensitivity can be lower for high energy gamma radiation than with certain other types of detector, because the density of the gas in the device is usually low, allowing most high energy gamma photons to pass through undetected (lower energy photons are easier to detect, and are better absorbed by the detector. Gamma rays (denoted as &gamma) are a form of Electromagnetic radiation or light emission of frequencies produced by sub-atomic particle interactions Examples of this are the X-ray Pancake Geiger Tube). X-radiation (composed of X-rays) is a form of Electromagnetic radiation. A better device for detecting gamma rays is a sodium iodide scintillation counter. Sodium iodide is a white Crystalline Salt with Chemical formula Na[[Iodine I]] used in radiation detection treatment of Iodine deficiency A scintillation counter measures Ionizing radiation. The Sensor, called a Scintillator, consists of a transparent Crystal, usually phosphor Good alpha and beta scintillation counters also exist, but Geiger detectors are still favored as general purpose alpha/beta/gamma portable contamination and dose rate instruments, due to their low cost and robustness. A variation of the Geiger tube is used to measure neutrons, where the gas used is Boron Trifluoride and a plastic moderator is used to slow the neutrons. This article is a discussion of neutrons in general For the specific case of a neutron found outside the nucleus see Free neutron. Boron trifluoride is the Chemical compound with the formula BF3 This creates alpha particle inside the detector and thus neutrons can be counted. Alpha particles (named after and denoted by the first letter in the Greek alphabet, α consist of two Protons and two Neutrons bound together into a

Types and applications

The configuration of GM tubes determines the types of radiation that it can detect. For example, a thin mica window on a GM Tube (shown here) will allow for the detection of alpha radiation, where as GM Tubes without a thin mica window are too thick for the alpha and low energy beta radiation to pass through and be detected.

The Geiger-Müller tube is one form of a class of radiation detectors called gaseous detectors or simply gas detectors. Although useful, cheap and robust, a counter using a GM tube can only detect the presence and intensity of radiation (particle frequency, as opposed to energy). Gas detectors with the ability to both detect radiation and determine particle energy levels (due to their construction, test gas, and associated electronics) are called proportional counters. A proportional counter is a measurement device to count particles of Ionizing radiation and measure their Energy. Some proportional counters can detect the position and or angle of the incident radiation as well. Other devices detecting radiation include:

ionization chamber, dosimeters, photomultiplier, semiconductor detectors and variants including CCDs, microchannel plates, scintillation counters, solid-state track detectors, cloud chambers, bubble chambers, spark chambers, neutron detectors and microcalorimeters. An ionization chamber is a device used for two major purposes detecting particles in air (as in a Smoke detector) and for detection or measurement of Ionizing radiation A dosimeter is any device used to measure an individual's exposure to a hazardous environment particularly when the hazard is cumulative over long intervals of Time Photomultiplier tubes ( photomultipliers or PMT s for short members of the class of Vacuum tubes and more specifically Phototubes are extremely A semiconductor detector is a device that uses a semiconductor (usually Silicon or Germanium) to detect A charge-coupled device ( CCD) is an analog Shift register, that enables the transportation of analog signals (electric charges through successive stages (capacitors A micro-channel plate (MCP is a planar component used for detection of particles ( Electrons or Ions and impinging Radiation ( Ultraviolet A scintillation counter measures Ionizing radiation. The Sensor, called a Scintillator, consists of a transparent Crystal, usually phosphor A solid state nuclear track detector or SSNTD (also known as an etched track detector or a dielectric track detector, DTD) is a sample of a solid The cloud chamber, also known as the Wilson chamber, is used for detecting particles of Ionizing radiation. A bubble chamber is a vessel filled with a superheated transparent Liquid (most often Liquid hydrogen) used to detect electrically charged A spark-chamber detector is a Particle detector, a device used in Particle physics for detecting electrically charged particles. Neutron detection is the effective detection of Neutrons entering a well-positioned Detector. A calorimeter is a device used for Calorimetry, the Science of measuring the heat of Chemical reactions or Physical changes as well as Heat

The Geiger-Müller counter has applications in the fields of nuclear physics, geophysics (mining) and medical therapy with isotopes and x-rays. Nuclear physics is the field of Physics that studies the building blocks and interactions of Atomic nuclei. Geophysics, a major discipline of Earth sciences, is the study of the Earth by quantitative physical methods especially by seismic, electromagnetic Mining is the extraction of valuable Minerals or other geological materials from the earth usually (but not always from an Ore body Some of the proportional counters have many internal wires and electrodes and are called multi-wire proportional counters or simply MWPCs. A multi-wire chamber (or just wire chamber) is a detector for particles of Ionizing radiation which is an advancement of the concept of the Geiger counter Radiation detectors have also been used extensively in nuclear physics, medicine, particle physics, astronomy and in industry. Medicine is the art and science of healing It encompasses a range of Health care practices evolved to maintain and restore Human Health by the Particle physics is a branch of Physics that studies the elementary constituents of Matter and Radiation, and the interactions between them Astronomy (from the Greek words astron (ἄστρον "star" and nomos (νόμος "law" is the scientific study

History

Cold War-era survey meter (this is an ion chamber, not a Geiger counter)

Hans Geiger developed a device (that would later be called the "Geiger counter") in 1908 together with Ernest Rutherford. Johannes (Hans Wilhelm Geiger ( September 30, 1882 &ndash September 24, 1945) was a German Physicist. Ernest Rutherford 1st Baron Rutherford of Nelson, OM, PC, FRS (30 August 1871 – 19 October 1937 was a New Zealand Physicist This counter was only capable of detecting alpha particles. In 1928, Geiger and Walther Müller (a PhD student of Geiger) improved the counter so that it could detect all kinds of ionizing radiation. Walther Müller ( September 6, 1905 in Hanover &ndash December 4, 1979 in Walnut Creek California) was a German

The current version of the "Geiger counter" is called the halogen counter. It was invented in 1947 by Sidney H. Liebson (Phys. Sidney H Liebson (born 1920 received his PhD from the University of Maryland in 1947 Rev. 72, 602–608 (1947)). It has superseded the earlier Geiger counter because of its much longer life. The devices also used a lower operating voltage.

See also

• Civil Defense Geiger Counters
• Geiger-Müller tube
• Radioactive decay
• Geiger plateau
• Gaseous ionization detectors
• Ionization chamber

External links

Patents

Electric lamps and discharge devices of the Geiger-Müller type (Class 313/93)

• U.S. Patent 625,823 , K. Most Civil Defense Geiger Counters were issued by the United States Civil Defense during the 1960s in the midst of the Cold War in an effort to help prepare A Geiger-Müller tube (or GM tube) is the sensing element of a Geiger counter instrument that can detect a single particle of Ionizing radiation, and typically Radioactive decay is the process in which an unstable Atomic nucleus loses energy by emitting ionizing particles and Radiation. The Geiger plateau is the voltage range in which the Geiger-Müller counter operates In Particle physics, gaseous ionization detectors are detectors designed to seek the presence of particles (a Particle detector) An ionization chamber is a device used for two major purposes detecting particles in air (as in a Smoke detector) and for detection or measurement of Ionizing radiation Zickler, "Telegraphy by means of electric light"
• U.S. Patent 685,958 , N. Tesla, "Method of utilizing radiant energy"
• U.S. Patent 1,589,833 , H. There have already been discussions about Tesla's ethnicity on the talk page Benhken, "Measuring device for the examination of electromagnetic waves"
• U.S. Patent 1,855,669 , O. Glasser, "Method and apparatus for the measurement of radiation intensity"
• U.S. Patent 1,995,018 , H. J. Spanner, "Gas Filled Tube"
• U.S. Patent 2,081,041 , H. Kott, "Apparatus for measuring radiation"
• U.S. Patent 2,141,655 , H. Kott, "Radiation sensitive device"
• U.S. Patent 2,145,866 , G. Failla, "Electrotechnique"
• U.S. Patent 2,168,464 , S. Yeda, "Roentgenometer"
• U.S. Patent 2,197,453 , G. L. Hassler, "Method of underground exploration"
• U.S. Patent 2,221,374 , P. T. Farnsworth, "X-Ray projection device"
• U.S. Patent 2,257,827 , G. Philo Taylor Farnsworth ( August 19, 1906 – March 11, 1971) was an American inventor J. Weissenberg, "Electron Discharge Tube"
• U.S. Patent 2,397,071 , D. G. C. Hare, "Radiation detector"
• U.S. Patent 2,397,072 , D. G. C. Hare, "Radiation detector"
• U.S. Patent 2,397,073 , D. G. C. Hare, "Radiation detector"
• U.S. Patent 2,397,074 , D. G. C. Hare, "Radiation detector"
• U.S. Patent 2,397,075 , D. G. C. Hare, "Radiation detector"
• U.S. Patent 2,398,934 , D. G. C. Hare, "Radiation detector"
• U.S. Patent 2,440,511 , D. G. C. Hare, "Radiation detector"
• U.S. Patent 2,449,697 , A. Graves, "Ionization chambers, Geiger Müller tubes, and the like"
• U.S. Patent 2,397,661 , D. G. C. Hare, "Radiation detector"
• U.S. Patent 2,521,315 , J. A. Victoreen, "Geiger tube"
• U.S. Patent 2,542,440 , J. A. Victoreen, "Geiger tube"