|
Geiger-Müller Counter
A Geiger counter (also known as a Geiger–Müller counter) is an electronic instrument used for detecting and measuring ionizing radiation. It is widely used in applications such as radiation dosimetry, radiological protection, experimental physics, nuclear industry and the Manumouthry. It detects ionizing radiation such as alpha particles, beta particles, and gamma rays using the ionization effect produced in a Geiger–Müller tube, which gives its name to the instrument. In wide and prominent use as a hand-held radiation survey instrument, it is perhaps one of the world's best-known radiation detection instruments. The original detection principle was realized in 1908 at the University of Manchester, but it was not until the development of the Geiger–Müller tube in 1928 that the Geiger counter could be produced as a practical instrument. Since then, it has been very popular due to its robust sensing element and relatively low cost. However, there are limitations in mea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hans Geiger
Johannes Wilhelm "Hans" Geiger (; ; 30 September 1882 – 24 September 1945) was a German physicist. He is best known as the co-inventor of the detector component of the Geiger counter and for the Geiger–Marsden experiment which discovered the atomic nucleus. He was the brother of meteorologist and climatologist Rudolf Geiger. Biography Geiger was born at Neustadt an der Haardt, Germany. He was one of five children born to the Indologist Wilhelm Ludwig Geiger, who was a professor at the University of Erlangen. In 1902, Geiger started studying physics Physics is the natural science that studies matter, its fundamental constituents, its motion and behavior through space and time, and the related entities of energy and force. "Physical science is that department of knowledge which r ... and mathematics at the University of Erlangen and was awarded a doctorate in 1906. His thesis was on electrical discharges through gases. He received a fellowship to the Victo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geiger Counter In Use
Geiger may refer to: People *Geiger (surname) Places * Geiger, Alabama, a town * Geiger (crater), a lunar impact crater on the far side of the Moon * Geiger, South Sudan, a border town filled with refugees Other * Geiger counter, a device for detecting radiation ** Geiger–Müller tube, the sensing element of the a Geiger counter * Geiger–Marsden experiment, a 1909 physics experiment * Geiger–Nuttall law, an empirical 1911 rule relating alpha decay energy to decay half-life * Geiger tree (''Cordia sebestena''), a species of flowering plant * Geiger (corporation), a promotional products company * Geiger (comics), a minor, teenage Marvel Comics Marvel Comics is an American comic book publishing, publisher and the flagship property of Marvel Entertainment, a divsion of The Walt Disney Company since September 1, 2009. Evolving from Timely Comics in 1939, ''Magazine Management/Atlas Co ... super-heroine * USNS ''Geiger'', a transport ship in the United States Navy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geiger Counter 2
Geiger may refer to: People *Geiger (surname) Places * Geiger, Alabama, a town * Geiger (crater), a lunar impact crater on the far side of the Moon * Geiger, South Sudan, a border town filled with refugees Other * Geiger counter, a device for detecting radiation ** Geiger–Müller tube, the sensing element of the a Geiger counter * Geiger–Marsden experiment, a 1909 physics experiment * Geiger–Nuttall law, an empirical 1911 rule relating alpha decay energy to decay half-life * Geiger tree (''Cordia sebestena''), a species of flowering plant * Geiger (corporation), a promotional products company * Geiger (comics), a minor, teenage Marvel Comics Marvel Comics is an American comic book publishing, publisher and the flagship property of Marvel Entertainment, a divsion of The Walt Disney Company since September 1, 2009. Evolving from Timely Comics in 1939, ''Magazine Management/Atlas Co ... super-heroine * USNS ''Geiger'', a transport ship in the United States Navy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ion Chamber
The ionization chamber is the simplest type of gas-filled radiation detector, and is widely used for the detection and measurement of certain types of ionizing radiation, including X-rays, gamma rays, and beta particles. Conventionally, the term "ionization chamber" refers exclusively to those detectors which collect all the charges created by ''direct ionization'' within the gas through the application of an electric field. It only uses the discrete charges created by each interaction between the incident radiation and the gas. Gaseous ionization detectors include ionization chambers and devices that use gas multiplication, namely the proportional counter and the Geiger counter. Ion chambers have a good uniform response to radiation over a wide range of energies and are the preferred means of measuring high levels of gamma radiation. They are widely used in the nuclear power industry, research labs, radiography, radiobiology, and environmental monitoring. Principle of operation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clicking Noise
A click is a sonic artifact in sound and music production. Analog recording artifact On magnetic tape recordings, clicks can occur when switching from magnetic play to record in order to correct recording errors and when recording a track in sections. On phonograph records, clicks are perceived in various ways by the listener, ranging from tiny 'tick' noises which may occur in any recording medium through ' scratch' and 'crackle' noise commonly associated with analog disc recording methods. Analog clicks can occur due to dirt and dust on the grooves of the vinyl record or granularity in the material used for its manufacturing, or through damage to the disc from scratches on its surface. Digital recording artifact In digital recording, clicks (not to be confused with the click track) can occur due to multiple issues. When recording through an audio interface, insufficient computer performance or audio driver issues can cause clicks, pops and dropouts. They can result from i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sievert
The sievert (symbol: SvNot be confused with the sverdrup or the svedberg, two non-SI units that sometimes use the same symbol.) is a unit in the International System of Units (SI) intended to represent the stochastic health risk of ionizing radiation, which is defined as the probability of causing radiation-induced cancer and genetic damage. The sievert is important in dosimetry and radiation protection. It is named after Rolf Maximilian Sievert, a Swedish medical physicist renowned for work on radiation dose measurement and research into the biological effects of radiation. The sievert is used for radiation dose quantities such as equivalent dose and effective dose (radiation), effective dose, which represent the risk of external radiation from sources outside the body, and committed dose, which represents the risk of internal irradiation due to inhaled or ingested radioactive substances. According to the International Commission on Radiological Protection (ICRP) one sievert r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Absorbed Dose
Absorbed dose is a dose quantity which is the measure of the energy deposited in matter by ionizing radiation per unit mass. Absorbed dose is used in the calculation of dose uptake in living tissue in both radiation protection (reduction of harmful effects), and radiology (potential beneficial effects for example in cancer treatment). It is also used to directly compare the effect of radiation on inanimate matter such as in radiation hardening. The SI unit of measure is the gray (Gy), which is defined as one Joule of energy absorbed per kilogram of matter. The older, non-SI CGS unit rad, is sometimes also used, predominantly in the USA. Deterministic effects Conventionally, in radiation protection, unmodified absorbed dose is only used for indicating the immediate health effects due to high levels of acute dose. These are tissue effects, such as in acute radiation syndrome, which are also known as deterministic effects. These are effects which are certain to happen in a short ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Counts Per Minute
The measurement of ionizing radiation is sometimes expressed as being a ''rate'' of counts per unit time as registered by a radiation monitoring instrument, for which counts per minute (cpm) and counts per second (cps) are commonly used quantities. Count rate measurements are associated with the detection of particles, such as alpha particles and beta particles. However, for gamma ray and X-ray dose measurements a unit such as the sievert is normally used. Both cpm and cps are the rate of detection events registered by the measuring instrument, not the rate of emission from the source of radiation. For radioactive decay measurements it must not be confused with disintegrations per unit time (dpm), which represents the rate of atomic disintegration events at the source of the radiation. Count rates The count rates of cps and cpm are generally accepted and convenient practical rate measurements. They are not SI units, but are ''de facto'' radiological units of measure in widespre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Townsend Discharge
The Townsend discharge or Townsend avalanche is a gas ionisation process where free electrons are accelerated by an electric field, collide with gas molecules, and consequently free additional electrons. Those electrons are in turn accelerated and free additional electrons. The result is an avalanche breakdown, avalanche multiplication that permits electrical conduction through the gas. The discharge requires a source of free electrons and a significant electric field; without both, the phenomenon does not occur. The Townsend discharge is named after John Sealy Townsend, who discovered the fundamental ionisation mechanism by his work circa 1897 at the Cavendish Laboratory, Cambridge. General description of the phenomenon The avalanche occurs in a gaseous medium that can be ionization, ionised (such as air). The electric field and the mean free path of the electron must allow free electrons to acquire an energy level (velocity) that can cause impact ionisation. If the electric fi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photon
A photon () is an elementary particle that is a quantum of the electromagnetic field, including electromagnetic radiation such as light and radio waves, and the force carrier for the electromagnetic force. Photons are massless, so they always move at the speed of light in vacuum, (or about ). The photon belongs to the class of bosons. As with other elementary particles, photons are best explained by quantum mechanics and exhibit wave–particle duality, their behavior featuring properties of both waves and particles. The modern photon concept originated during the first two decades of the 20th century with the work of Albert Einstein, who built upon the research of Max Planck. While trying to explain how matter and electromagnetic radiation could be in thermal equilibrium with one another, Planck proposed that the energy stored within a material object should be regarded as composed of an integer number of discrete, equal-sized parts. To explain the photoelectric effect, Eins ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Elementary Particle
In particle physics, an elementary particle or fundamental particle is a subatomic particle that is not composed of other particles. Particles currently thought to be elementary include electrons, the fundamental fermions ( quarks, leptons, antiquarks, and antileptons, which generally are matter particles and antimatter particles), as well as the fundamental bosons ( gauge bosons and the Higgs boson), which generally are force particles that mediate interactions among fermions. A particle containing two or more elementary particles is a composite particle. Ordinary matter is composed of atoms, once presumed to be elementary particles – ''atomos'' meaning "unable to be cut" in Greek – although the atom's existence remained controversial until about 1905, as some leading physicists regarded molecules as mathematical illusions, and matter as ultimately composed of energy. Subatomic constituents of the atom were first identified in the early 1930s; the electron and the proto ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
