ionization chamber (redirected from ionization chambers)

chamber /cham·ber/ (chām´ber) an enclosed space.

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anterior chamber of eye  the part of the aqueous-containing space of the eyeball between the cornea and the iris.

aqueous chamber  the part of the eyeball filled with aqueous humor; see anterior c. and posterior c.

counting chamber  the part of a hemacytometer consisting of a microscopic slide with a depression whose base is marked in grids, and into which a measured volume of a sample of blood or bacterial culture is placed and covered with a cover glass. Cells and formed blood elements in any given square can then be counted under a microscope.

diffusion chamber  an apparatus for separating a substance by means of a semipermeable membrane.

Haldane chamber  an air-tight chamber in which animals are confined for metabolic studies.

hyperbaric chamber  an enclosed space in which gas (oxygen) can be raised to greater than atmospheric pressure.

ionization chamber  an enclosure containing two or more electrodes between which an electric current may be passed when the enclosed gas is ionized by radiation; used for determining the intensity of x-rays and other rays.

posterior chamber of eye  the part of the aqueous-containing space of the eyeball between the iris and the lens.

pulp chamber  the natural cavity in the central portion of the tooth crown that is occupied by the dental pulp.

relief chamber  the recess in a denture surface that rests on the oral structures, to reduce or eliminate pressure.

Thoma-Zeiss counting chamber  a common type of counting c.

vitreous chamber  the vitreous-containing space in the eyeball, bounded anteriorly by the lens and ciliary body and posteriorly by the posterior wall of the eyeball.

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ionization chamber

n.

A chamber for detecting ionization of the enclosed gas, used for determining the intensity of ionizing radiation.

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ionization chamber,

a small cavity filled with air that collects the ionic charge liberated during irradiation. The exposure and dose of radiation can be calculated from the amount of change liberated and the mass of air in the chamber.

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chamber,

n an enclosed area.

chamber, air-equivalent ionization,

n a chamber in which the materials of the wall and electrodes produce ionization essentially similar to that produced in a free-air ionization chamber.

chamber, air-wall ionization,

n an ionization chamber with walls of material of low atomic number, having the same effective atomic number as atmospheric air.

chamber, extrapolation ionization

n an ionization chamber with electrodes of which the spacing can be adjusted and accurately determined to permit extrapolation of its reading to zero chamber volume.

chamber, free-air ionization,

n an ionization chamber in which a delimited beam of radiation passes between the electrodes without striking them or other internal parts of the equipment. The electric field is maintained perpendicular to the electrodes in the collecting region; as a result the ionized volume can be accurately determined from the dimensions of the collecting electrode and limiting diaphragm. This is the basic standard instrument for dosimetry within the range of 5 to 400 kV.

chamber, ionization

n an instrument for measuring the quantity of ionizing radiation, in terms of the charge of electricity associated with ions produced within a defined volume of air.

chamber, monitor ionization,

n an ionization chamber used for checking the constancy of performance of the roentgen-ray apparatus.

chamber, pocket ionization,

n a small, pocket-sized ionization chamber used for monitoring radiation exposure of personnel. Before use it is given a charge, and the amount of discharge is a measure of the quantity of radiation received.

chamber, pulp,

n (pulp cavity), the space occupied by the pulp.

chamber, relief,

n a recess in the impression surface of a denture created to reduce or eliminate pressure from the corresponding area of the oral cavity.

chamber, standard ionization,

n See chamber, ionization, free-air.

chamber, suction,

n See chamber, relief.

chamber, thimble ionization,

n a small cylindrical or spherical chamber, usually with walls of organic material.

chamber, thin-wall ionization,

n an ionization chamber having walls so thin that nearly all secondary corpuscular rays reaching them from external materials can penetrate them easily.

chamber, tissue-equivalent ionization,

n a chamber in which the walls, electrodes, and gas are selected to produce ionization essentially equivalent to the characteristics of the tissue under consideration.

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ionization (ī´änizā´shn),

n the process or the result of a process by which a neutral atom or molecule acquires either a positive or negative charge.

ionization chamber,

n See chamber, ionization.

ionization, chamber, air-equivalent,

n See chamber, ionization, air-equivalent.

ionization density,

n the number of ion pairs per unit volume.

ionization path (ionization track),

n the trail of ion pairs produced by ionizing radiation in its passage through matter.

ionization potential,

n the potential necessary to separate one electron from an atom, resulting in the formation of an ion pair.

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chamber

an enclosed space.

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anterior chamber

the part of the aqueous humor-containing space of the eyeball between the cornea and iris.

hyperbaric chamber

an enclosed space in which gas (oxygen) can be raised to greater than atmospheric pressure. See also hyperbaric oxygenation.

ionization chamber

see ionization chamber.

posterior chamber

that part of the aqueous humor-containing space of the eyeball between the iris and the lens.

vitreous chamber

the vitreous humor-containing space in the eyeball, bounded anteriorly by the lens and ciliary body and posteriorly by the posterior wall of the eyeball.

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ionization

1. the dissociation of a substance in solution into ions.

2. iontophoresis.

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ionization chamber

an enclosure containing two or more electrodes between which an electric current may be passed when the enclosed gas is ionized by radiation; used for determining the intensity of x-rays and other rays.