Geiger counter

Geiger Counter

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Geiger counter

A Geiger counter, also called a Geiger-Müller counter, is a type of particle detector

Particle detector

In experimental and applied particle physics and nuclear engineering, a particle detector, also known as a radiation detector, is a device used to detect, track, and/or identify high-energy Elementary particles, such as those produced by nuclear decay, cosmic radiation, or reactions in a particle accelerator....
that measures ionizing radiation

Ionizing radiation

Ionizing radiation consists of subatomic particle radiation or electromagnetic radiation that are energetic enough to detach electrons from atoms or molecules, ionize them....
.

er counters are used to detect radiation (usually gamma and beta radiation, but certain models can also detect alpha radiation). The sensor is a Geiger-Müller tube

Geiger-Müller tube

A Geiger-M?ller tube is the sensing element of a Geiger counter instrument that can detect a single particle of ionizing radiation, and typically produce an audible click for each....
, an inert gas-filled tube (usually helium

Helium

Helium is a colorless, odorless, tasteless, non-toxic, inert monatomic chemical element that heads the noble gas group in the periodic table and whose atomic number is 2....
, neon

Neon

Neon is the chemical element that has the symbol Ne and atomic number 10. Although a very common element in the universe, it is rare on Earth....
or argon

Argon

Argon is a chemical element designated by the symbol Ar. Argon has atomic number 18 and is the third element in group 18 of the periodic table ....
with halogen

Halogen

|}The halogens or halogen elements are a chemical series of nonmetal chemical element from Periodic table group International Union of Pure and Applied Chemistry of the periodic table, comprising fluorine, F; chlorine, Cl; bromine, Br; iodine, I; and astatine, At....
s added) that briefly conducts electricity when a particle

Elementary particle

In particle physics, an elementary particle or fundamental particle is a wiktionary:particle not known to have substructure; that is, it is not known to be made up of smaller particles....
or photon

Photon

In physics, the photon is an elementary particle, the quantum of the electromagnetic field and the basic unit of light and all other forms of electromagnetic radiation....
of radiation makes the gas conductive.

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Description

Geiger counters are used to detect radiation (usually gamma and beta radiation, but certain models can also detect alpha radiation). The sensor is a Geiger-Müller tube

Geiger-Müller tube

Helium

Helium is a colorless, odorless, tasteless, non-toxic, inert monatomic chemical element that heads the noble gas group in the periodic table and whose atomic number is 2....
, neon

Neon

Neon is the chemical element that has the symbol Ne and atomic number 10. Although a very common element in the universe, it is rare on Earth....
or argon

Argon

Argon is a chemical element designated by the symbol Ar. Argon has atomic number 18 and is the third element in group 18 of the periodic table ....
with halogen

Halogen

Elementary particle

Photon

Electron avalanche

An electron avalanche is a process in which a number of free electrons in a Transmission medium are subjected to strong acceleration by an electric field, ionizing the medium's atoms by collision , thereby forming "new" electrons to undergo the same process in successive cycles....
effect and outputs a current pulse, which is then often displayed by a needle or lamp and/or audible clicks. Modern instruments can report radioactivity over several orders of magnitude. Some Geiger counters can 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. Examples of this are the X-ray

X-ray

X-radiation is a form of electromagnetic radiation. X-rays have a wavelength in the range of 10 to 0.01 nanometers, corresponding to frequency in the range 30 Hertz to 30 Hertz and energies in the range 120 Electron volt to 120 keV....
Pancake Geiger Tube). A better device for detecting gamma rays is a sodium iodide

Sodium iodide

Sodium iodide is a white, crystalline salt with chemical formula SodiumIodine used in radiation detection, treatment of iodine deficiency, and as a reactant in the Finkelstein reaction....
scintillation counter

Scintillation counter

A scintillation counter measures ionizing radiation. The sensor, called a scintillator, consists of a transparent crystal, usually phosphor, plastic , or organic liquid that fluoresces when struck by ionizing radiation....
. 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

Boron trifluoride

Boron trifluoride is the chemical compound with the chemical formula BF3. This pungent colourless toxic gas forms white fumes in moist air....
and a plastic moderator is used to slow the neutrons. This creates an alpha particle

Alpha particle

Alpha particles consist of two protons and two neutrons bound together into a particle identical to a helium atomic nucleus; hence, it can be written as He2+ or 42He2+....
inside the detector and thus neutrons can be counted.

Types and applications

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 counter

Proportional counter

A proportional counter is a measurement device to count Charged particles of ionizing radiation and measure their energy.A proportional counter is a type of gaseous ionization detector - it works on the same principle as the Geiger counter, but uses a lower operating voltage....
s. Some proportional counters can detect the position and or angle of the incident radiation as well. Other devices detecting radiation include:

ionization chamber
Ionization chamber

An ionization chamber is a device used for two major purposes: detecting particles in air , and for detection or measurement of ionizing radiation....
s
dosimeter
Dosimeter

A dosimeter is a device used to measure an individual's exposure to a hazardous environment, particularly when the hazard is cumulative over long intervals of time, or one's bio-accumulation....
s
photomultiplier
Photomultiplier

Photomultiplier tubes , members of the class of vacuum tubes, and more specifically phototubes, are extremely sensitive detectors of light in the ultraviolet, visible light, and near-infrared ranges of the electromagnetic spectrum....
s
semiconductor detector
Semiconductor detector

This article is about particle detector. For information about semiconductor detectors in radio, see Diode#Semiconductor_diodes, rectifier, detector and cat's-whisker detector....
s and variants including CCD
Charge-coupled device

A charge-coupled device is an analog signal shift register that enables the transportation of analog signals through successive stages , controlled by a clock signal....
s
microchannel plates
scintillation counter
Scintillation counter

A scintillation counter measures ionizing radiation. The sensor, called a scintillator, consists of a transparent crystal, usually phosphor, plastic , or organic liquid that fluoresces when struck by ionizing radiation....
s
solid-state track detector
Solid state nuclear track detector

A solid state nuclear track detector or SSNTD is a sample of a solid material exposed to nuclear radiation , industrial etching, and examined microscopically....
s
cloud chamber
Cloud chamber

[Image:Cloud_chamber_bionerd.jpg|thumb|Cloud chamber with visible tracks from ionizing radiation The cloud chamber, also known as the Wilson chamber, is used for detecting particles of ionizing radiation....
s
bubble chamber
Bubble chamber

A bubble chamber is a vessel filled with a superheating transparency liquid used to detect electrically charged particles moving through it....
s
spark chambers
neutron detector
Neutron detection

Neutron detection is the effective detection of neutrons entering a well-positioned detector. There are two key aspects to effective neutron detection: hardware and software....
s
microcalorimeter
Calorimeter

| |}A calorimeter is a device used for calorimetry, the science of measuring the heat of chemical reactions or physical changes as well as heat capacity....
s

The Geiger-Müller counter has applications in the fields of nuclear physics

Nuclear physics

Nuclear physics is the field of physics that studies the building blocks and interactions of atomic nuclei.The most commonly known applications of nuclear physics are nuclear power and nuclear weapons, but the research field is also the basis for a far wider range of applications, including in the medical sector , in materials engineering...
, geophysics

Geophysics

Geophysics, a major discipline of the Earth sciences, is the study of the Earth by the quantitative observation of its physical properties, especially by Seismology, Electromagnetism, Radioactive decay, galvanic and potential field methods....
(mining

Mining

Mining is the extraction of value minerals or other geology materials from the earth, usually from an ore body, vein or seam. Materials recovered by mining include base metals, precious metals, iron, uranium, coal, diamonds, limestone, oil shale, Sodium chloride and potash....
) and medical therapy with isotopes and x-rays. Some of the proportional counters have many internal wires and electrodes and are called multi-wire proportional counter

Wire chamber

A multi-wire chamber is a detector for particles of ionizing radiation which is an advancement of the concept of the Geiger counter and the proportional counter....
s or simply MWPCs. Radiation detectors have also been used extensively in nuclear physics, medicine

Medicine

Medicine is the art and science of healing. It encompasses a range of health care practices evolved to maintain and restore health by the prevention and treatment of illness....
, particle physics

Particle physics

Particle physics is a branch of physics that studies the elementary particle constituents of matter and radiation, and the interactions between them....
, astronomy

Astronomy

Astronomy is the science of Astronomical object and Phenomenon that originate outside the Earth's atmosphere . It is concerned with the evolution, physics, chemistry, meteorology, and motion of celestial objects, as well as the physical cosmology....
and in industry.

History

Hans Geiger

Johannes Wilhelm Geiger was a Germany physicist. He is perhaps best known as the co-inventor of the Geiger counter and for the Geiger-Marsden experiment which discovered the atomic nucleus....
developed a device (that would later be called the "Geiger counter") in 1908 together with Ernest Rutherford. This counter was only capable of detecting alpha particles. In 1928, Geiger and Walther Müller

Walther Müller

Walther M?ller , was a Germany physicist, most well known for his improvement of Hans Geiger's counter for ionizing radiation, now known as the Geiger-M?ller tube....
(a PhD student of Geiger) improved the counter so that it could detect all kinds of ionizing radiation.

The current version of the "Geiger counter" is called the halogen counter. It was invented in 1947 by Sidney H. Liebson

Sidney H. Liebson

Sidney H. Liebson received his Ph.D. from the University of Maryland, College Park in 1947. His thesis was on the discharge mechanism of Geiger counter....
(Phys. 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.

External links

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

', K. Zickler, "Telegraphy by means of electric light"
', N. Tesla
Nikola Tesla

Nikola Tesla was an inventor and a mechanical engineer and electrical engineer. Tesla was born in the village of Smiljan near the town of Gospic, in Croatia ....
, "Method of utilizing radiant energy"
', H. Benhken, "Measuring device for the examination of electromagnetic waves"
', O. Glasser, "Method and apparatus for the measurement of radiation intensity"
', H. J. Spanner, "Gas Filled Tube"
', H. Kott, "Apparatus for measuring radiation"
', H. Kott, "Radiation sensitive device"
', G. Failla, "Electrotechnique"
', S. Yeda, "Roentgenometer"
', G. L. Hassler, "Method of underground exploration"
', P. T. Farnsworth
Philo Farnsworth

Philo Taylor Farnsworth was an United States inventor. He is best known for inventing the first completely electronic television. In particular, he was the first to make a working electronic image pickup device , and the first to demonstrate an all-electronic television system to the public....
, "X-Ray projection device"
', G. J. Weissenberg, "Electron Discharge Tube"
', D. G. C. Hare, "Radiation detector"
', D. G. C. Hare, "Radiation detector"
', D. G. C. Hare, "Radiation detector"
', D. G. C. Hare, "Radiation detector"
', D. G. C. Hare, "Radiation detector"
', D. G. C. Hare, "Radiation detector"
', D. G. C. Hare, "Radiation detector"
', A. Graves, "Ionization chambers, Geiger Müller tubes, and the like"
', D. G. C. Hare, "Radiation detector"
', J. A. Victoreen, "Geiger tube"
', J. A. Victoreen, "Geiger tube"

Geiger counter

Description

Types and applications

History

See also

External links