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 smoke detector or smoke alarm is an active fire protection device, subject to stringent bounding, that detects airborne smoke and issues an audible alarm, thereby alerting nearby people to the danger of fire. ... Radiation hazard symbol. ...

An ionization chamber is an instrument constructed to measure the number of ions within a gas (or more rarely solid or liquid) filled enclosure between two conducting metal plates (or two electrodes of some shape) separated by a gap, each ion essentially deposits/removes a small electric charge on the plate(s)the more ions in the chamber the more charge on the plates. There is also often a voltage potential placed on or near the plates, which allows the device to work continuously, and mops up electrons so that the device doesn't become saturated (called a bias current), without this 'bias current' the device will reach a point at which no more ions can collect on the plate and the device will fail to work, this bias current (actually applied as a voltage) can be as low as a few volts or many thousands. The electrodes may be in the form of parallel plates or of coaxial cylinders to form a convienient portable detector. One of the electrodes may be the wall of the vessel itself. When gas between the electrodes is ionized by any means, such as by alpha particles beta particles, X-rays, or other radioactive emission, or simply ions produced from a high voltage source, the ions move to the electrodes of the opposite polarity/sign, thus creating an ionization current, which may be measured by a galvanometer or these days an electrometer Multivalent redirects here. ... Alternative meanings: There is also an Electric-type Pokémon named Electrode. ... Look up charge in Wiktionary, the free dictionary. ... International safety symbol Caution, risk of electric shock (ISO 3864), colloquially known as high voltage symbol. ... The electron is a fundamental subatomic particle that carries a negative electric charge. ... The term saturation generally means thoroughly full, and can refer to the following: In chemistry, see saturation (chemistry) for a number of meanings. ... Alpha may refer to: The Greek letter alpha Alpha (letter), a letter in the Greek alphabet. ... Beta is the second letter of the Greek alphabet (β). Beta may also refer to: In mathematics, statistics, and economics: Beta function in mathematics Beta distribution in statistics Beta coefficient in finance Standardized coefficient in statistics, also sometimes known as beta coefficient In physics: Beta-function in quantum field theory Beta... In the NATO phonetic alphabet, X-ray represents the letter X. An X-ray picture (radiograph) taken by Röntgen An X-ray is a form of electromagnetic radiation with a wavelength approximately in the range of 5 pm to 10 nanometers (corresponding to frequencies in the range 30 PHz... Radioactive decay is the set of various processes by which unstable atomic nuclei (nuclides) emit subatomic particles. ... The polarity of an object is, in general, its physical alignment of atoms. ... It has been suggested that Tangent galvanometer be merged into this article or section. ... An electrometer is an electrical instrument for measuring electric charge or electrical potential difference. ...

Ionization Chambers are widely used in the nuclear industry since they provide an output that is proportional to dose and have a greater operating lifetime than standard Geiger tubes (in gieger tubes the gas breaks down eventually). Ionization chambers are used extensivly in nuclear medicine to determine the exact activity of radioactive therapeutic treatments, (such devices are called 'Radioisotope Dose Calibrators'). Ion Chambers are sometimes microphonic since they are very sensitive devices and non ion related charges can be setup inside due to the Piezo electricity effect. Dose can refer to several things: An amount of medication to be taken at one time. ... Microphonics are noises in a loudspeaker caused by mechanical shock or vibration of the electronic components. ... Piezoelectricity is the ability of certain crystals to produce a voltage when subjected to mechanical stress. ...

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An example of an ion chamber used in hospitals

Radiation detectors

A Geiger-Müller tube—used in a Geiger counter—is another type of ionization chamber. In such a tube, one plate is wrapped into a cylinder. In place of the other plate is a wire placed along the cylindrical plate's axis. This type of tube is usually sealed and filled with an inert gas. In this device, no current normally flows between the two electrodes even though they are held at different potentials. 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 produce an audible click for each. ... Modern geiger counter. ...

If a particle of ionizing radiation enters the tube (an alpha particle, a beta particle, or a gamma ray) then a trail of ions will be created. These ions will briefly allow a conducting path to form between the electrodes, triggering a brief pulse of current. If this output is connected to headphones, one hears the familiar staccato pops of a Geiger counter. Alpha radiation consists of helium nuclei and is readily stopped by a sheet of paper. ... This article is about electromagnetic radiation. ... In musical notation, staccato indicates that notes are sounded in a detached and distinctly separate manner with their lengths shortened; that is, a short silence should be between the notes, without affecting the rhythm. ...

Many different types of radiation counters and detectors are based on Geiger-Müller tube-like devices. Some contain different fill gases; some are filled with liquids; some are open to air. Different measurements are possible depending on the type of window in the device (a glass window will not pass alpha particles, while a mica window will) or the potential difference between the electrodes.

True Ionization Chambers, essentially turn radiation into a small electrical current flow (not a pulse) and are widely used in the nuclear industry since they provide an output that is proportional to dose and have a greater operating lifetime than Geiger tubes. Ionization chambers are used in nuclear medicine to determine the exact activity of radioactive therapeutic treatment, such devices are called 'Radioisotope Dose Calibrators'. Dose can refer to several things: An amount of medication to be taken at one time. ...

With the development of cosmic ray physics and nuclear physics it became desirable to alter the simple Geiger counter, an "all or nothing" proposition, so as to discriminate among incident ionizing particles according to the energy. The more sophisticated detector that resulted is the proportional counter. Cosmic rays can loosely be defined as energetic particles originating outside of the Earth. ... Nuclear physics is the branch of physics concerned with the nucleus of the atom. ... Modern geiger counter. ... A proportional counter is a measurement device to count particles of ionizing radiation and measure their energy. ...

Smoke detectors

In a smoke detector, the gap between the plates is exposed to open air. The chamber contains a small amount of americium-241, which is an emitter of alpha particles. These alpha particles carry a substantial amount of energy, and when they collide with gas in the ionization chamber (mostly nitrogen and oxygen) the momentum transferred can ionize the gas molecules—that is, the uncharged gas molecules will lose one or more electrons and become charged ions. A smoke detector or smoke alarm is an active fire protection device, subject to stringent bounding, that detects airborne smoke and issues an audible alarm, thereby alerting nearby people to the danger of fire. ... General Name, Symbol, Number americium, Am, 95 Chemical series actinides Group, Period, Block n/a, 7, f Appearance silvery white Atomic mass (243) g/mol Electron configuration [Rn] 5f7 7s2 Electrons per shell 2, 8, 18, 32, 25, 8, 2 Physical properties Phase solid Density (near r. ... An alpha particle is deflected by a magnetic field Alpha particles (named after the first letter in the Greek alphabet, α) are a highly ionizing form of particle radiation which have low penetration. ... General Name, Symbol, Number nitrogen, N, 7 Chemical series nonmetals Group, Period, Block 15, 2, p Appearance colorless Atomic mass 14. ... General Name, Symbol, Number oxygen, O, 8 Chemical series Nonmetals, chalcogens Group, Period, Block 16, 2, p Appearance colorless (gas) very pale blue (liquid) Atomic mass 15. ... Multivalent redirects here. ...

Since the plates are at different voltages (in a typical smoke detector, the voltage difference is a few hundred volts) the ions and electrons will be attracted to the plates. This small flow of ions between the plates represents a measurable electric current. If smoke enters the detector, it disrupts this current. Ions strike smoke particles and are neutralized. This drop in current triggers the alarm. Electric current is by definition the flow of electric charge. ... Smoke from a wildfire Smoke is a suspension in air (aerosol) of small particles resulting from incomplete combustion of a fuel. ...