infrared radiation


Also found in: Dictionary, Thesaurus, Acronyms, Encyclopedia, Wikipedia.
Related to infrared radiation: Infrared Technology

radiation

 [ra″de-a´shun]
1. a proceeding outward from a common center.
2. a structure made up of parts that go outward from a center, especially a tract of the central nervous system made up of fibers that go out in different dfirections.
3. energy carried by waves or a stream of particles. One type is electromagnetic radiation, which consists of wave motion of electric and magnetic fields. The quantum theory is based on the fact that electromagnetic waves consist of discrete “packets” of electromagnetic radiation, called photons, which have neither mass nor charge and have an energy inversely proportional to the wavelength of the wave. In order of increasing photon energy and decreasing wavelength, the electromagnetic spectrum is divided into radio waves, infrared light, visible light, ultraviolet light, and x-rays. 

Another type is the radiation emitted by radioactive materials. alpha particles are high-energy helium-4 nuclei consisting of two protons and two neutrons, emitted by radioisotopes of heavy elements such as uranium. beta particles are high-energy electrons emitted by radioisotopes of lighter elements. gamma rays are high-energy photons emitted along with alpha and beta particles and also emitted alone by metastable radionuclides, such as technetium-99m. Gamma rays have energies in the x-ray region of the spectrum and differ from x-rays only in that they are produced by radioactive decay rather than by x-ray machines.

Radiation with enough energy to knock electrons out of atoms and produce ions is called ionizing radiation and includes alpha particles, beta particles, x-rays, and gamma rays. This kind of radiation can produce tissue damage directly by striking a vital molecule, such as DNA, or indirectly by striking a water molecule and producing highly reactive free radicals that chemically attack vital molecules. The effects of radiation can kill cells, make them unable to reproduce, or cause nonlethal mutations, producing cancer cells or birth defects in offspring. The radiosensitivity of normal tissues or cancer cells increases with their rate of cell division and decreases with their rate of cell specialization. Highly radiosensitive cells include lymphocytes, bone marrow hematopoietic cells, germ cells, and intestinal epithelial cells. Radiosensitive cancers include leukemias and lymphomas, seminoma, dysgerminoma, granulosa cell carcinoma, adenocarcinoma of the gastric epithelium, and squamous cell carcinoma of skin, mouth, nose and throat, cervix, and bladder.

The application of radiation, whether by x-ray or radioactive substances, for treatment of various illnesses is called radiation therapy or radiotherapy.

Three types of units are used to measure ionizing radiation. The roentgen (R) is a unit of exposure dose applicable only to x-rays and gamma rays. It is the amount of radiation that produces 2.58 × 10−4 coulomb of positive and negative ions passing through 1 kilogram of dry air. The rad is a unit of absorbed dose equal to 100 ergs of energy absorbed per 1 g of absorbing material; the absorbed dose depends both on the type of radiation and on the material in which it is absorbed. The rem is a unit of absorbed dose equivalent that produces the same biologic effect as 1 rad of high-energy x-rays. For beta and gamma radiation, 1 rem is approximately equal to 1 rad; for alpha radiation, 1 rad is approximately 20 rem.

Previously, doses administered in radiation therapy were commonly specified as measured exposure doses in roentgens. The current practice is to specify the absorbed dose in the tissue or organ of interest in rads. Many personnel monitoring devices read out in rems. Eventually, the rad and rem may be replaced by the new SI units, the gray and sievert; 1 gray equals 100 rad, and 1 sievert equals 100 rem.
Radiation Hazards. Harmful effects of radiation include serious disturbances of bone marrow and other blood-forming organs, burns, and sterility. There may be permanent damage to genes, which results in genetic mutations. The mutations can be transmitted to future generations. Radiation also may produce harmful effects on the embryo or fetus, bringing about fetal death or malformations. Long-term studies of groups of persons exposed to radiation have shown that radiation acts as a carcinogen; that is, it can produce cancer, especially leukemia. It also may predispose persons to the development of cataracts. 

Exposure to large doses of radiation over a short period of time produces a group of symptoms known as the acute radiation syndrome. These symptoms include general malaise, nausea, and vomiting, followed by a period of remission of symptoms. Later, the patient develops more severe symptoms such as fever, hemorrhage, fluid loss, anemia, and central nervous system involvement. The symptoms then gradually subside or become more severe, and may lead to death.
Radiation Protection. In order to avoid the radiation hazards mentioned above, one must be aware of the three basic principles of time, distance, and shielding involved in protection from radiation. Obviously, the longer one stays near a source of radiation the greater will be the exposure. The same is true of proximity to the source; the closer one gets to a source of radiation the greater the exposure. 

Shielding is of special importance when time and distance cannot be completely utilized as safety factors. In such instances lead, which is an extremely dense material, is used as a protective device. The walls of diagnostic x-ray rooms are lined with lead, and lead containers are used for radium, cobalt-60, and other radioactive materials used in radiotherapy.

Monitoring devices such as the film badge, thermoluminescent dosimeter, or pocket monitor are worn by persons working near sources of radiation. These devices contain special detectors that are sensitive to radiation and thus serve as guides to the amount of radiation to which a person has been exposed. For monitoring large areas in which radiation hazards may pose a problem, survey meters such as the Geiger counter may be used. The survey meter also is useful in finding sources of radiation such as a radium implant, which might be lost.

Sensible use of these protective and monitoring devices can greatly reduce unnecessary exposure to radiation and allow for full realization of the many benefits of radiation.
Penetrating capacity of different types of radiation. From Ignatavicius and Workman, 2002.
Radiation is emitted by radioactive material. Radiation quantity is measured in roentgens, rads, or rems, depending on precise use. From Bushong, 2001.
corpuscular radiation particles emitted in nuclear disintegration, including alpha and beta particles, protons, neutrons, positrons, and deuterons.
electromagnetic radiation energy, unassociated with matter, that is transmitted through space by means of waves (electromagnetic waves) traveling in all instances at 3×1010 cm or 186,284 miles per second, but ranging in length from 1011 cm (electrical waves) to 10−12 cm (cosmic rays) and including radio waves, infrared, visible light and ultraviolet, x-rays, and gamma rays.
extrafocal radiation radiation that arises from a source other than the focal spot of the x-ray tube.
infrared radiation the portion of the spectrum of electromagnetic radiation of wavelengths between 0.75 and 1000 μm; see also infrared.
interstitial radiation energy emitted by radium, radon, or some other radiopharmaceutical inserted directly into the tissue; see also radiation therapy.
ionizing radiation corpuscular or electromagnetic radiation that is capable of producing ions, directly or indirectly, in its passage through matter. See also radiation.
optic radiation either of two large fan-shaped fiber tracts in the brain extending from the lateral geniculate body on either side to the striate cortex
primary radiation that coming directly from a source, such as a radioactive substance or an x-ray tube, without interactions with matter.
pyramidal radiation fibers extending from the pyramidal tract to the cortex.
scatter radiation (secondary radiation) that generated by the interaction of primary radiation with matter. See illustration.
Three types of radiation—the useful beam, leakage radiation, and scatter radiation. From Bushong, 2001.
striothalamic radiation a fiber system joining the thalamus and the hypothalamic region.
tegmental radiation fibers radiating laterally from the nucleus ruber.
thalamic r's fibers streaming out through the lateral surface of the thalamus, through the internal capsule to the cerebral cortex.
ultraviolet radiation the portion of the spectrum of electromagnetic radiation of wavelengths between 0.39 and 0.18 μm; see also ultraviolet rays.

infrared radiation

[in′frəred′]
Etymology: L, infra + AS, read, red; L, radiare, to emit rays
electromagnetic radiation with wavelengths between about 700 nm and 1 mm, longer than those of visible light but shorter than those of microwaves and radio waves. Infrared radiation that strikes the body surface is perceived as heat.

radiation

(rad-e-a'shon) [L. radiatio, a shining]
1. The process by which energy is propagated through space or matter.
2. The emission of rays in all directions from a common center.
3. Ionizing rays used for diagnostic or therapeutic purposes. Two types of radiation therapy are commonly used for patients with cancer: teletherapy and brachytherapy. See: brachytherapy
4. Any form of radiant energy emission or divergence, as of energy in all directions from luminous bodies, radiographical tubes, particle accelerators, radioactive elements, and fluorescent substances.
5. In neurology, a group of fibers that diverge from a common origin.

acoustic radiation

Auditory radiation.

actinic radiation

Ionizing electromagnetic radiation that can produce chemical changes, e.g., the damage done to skin by ultraviolet sunlight.

auditory radiation

A band of fibers that connect auditory areas of the cerebral cortex with the medial geniculate body of the thalamus. Synonym: acoustic radiation

background radiation

Total radioactivity from cosmic rays, natural radioactive materials, and other radiation that is present in a specific area.

braking radiation

Synonym: bremsstrahlung radiation

bremsstrahlung radiation

Diagnostic radiation produced at the target of the anode in an x-ray tube. An electron is accelerated at high speed from the x-ray tube cathode filament. It interacts with the nuclear field of a target atom, changing direction and losing energy that is emitted in the form of an ionizing radiation photon. The result is a heterogeneous beam.
Synonym: braking radiation

characteristic radiation

In radiology, the production of radiation in an anode caused by an interaction between an electron from the electron stream and an inner-shell electron of the target material. The result is an ejected electron, a positive atom, and an x-ray photon characteristic of the difference in binding energies between the atomic shells.

radiation of corpus callosum

All the fibers emanating from the corpus callosum into each cerebral hemisphere.

corpuscular radiation

Radiation composed of discrete elements or particles such as elements of atomic nuclei, i.e., alpha, beta, neutron, positron, or proton particles.

cosmic radiation

Ionizing radiation from the sun and other extraterrestrial sources. It has a short wavelength, high velocity, and an exceptional ability to penetrate tissue. It accounts for about one tenth of the yearly total of ionizing radiation exposure for each person. Colloquially, it is known as “cosmic rays.”

electromagnetic radiation

Photons that travel at the speed of light. They exhibit both magnetic and electrical properties.
See: electromagnetic spectrum for table

heterogeneous radiation

Radiation containing waves of various wavelengths.

homogeneous radiation

Radiation containing photons of similar wavelength.

infrared radiation

Infrared ray.

interstitial radiation

Radiation treatment accomplished by inserting sealed sources of a particle emitter directly into tissues.

ionizing radiation

Electromagnetic waves capable of producing ions after interaction with matter. Examples include x-rays, gamma rays, and beta particles.
See: ionizing radiation injury

irritative radiation

An overdose of ultraviolet irradiation resulting in erythema and, in exceptional cases, blister formation.

low-level radiation

Electromagnetic waves at intensity levels below that known to cause obvious damage to living things. Low-level radiation includes that emitted by power lines, nuclear power plants, and appliances such as electric blankets, television sets, and computer terminals.

nonionizing radiation

Abbreviation: NIR
Electromagnetic radiation that does not readily ionize atoms such as that in visible light, ultraviolet light, infrared light, microwaves, ultrasound, and radiofrequency emissions.

optic radiation

A system of fibers extending from the lateral geniculate body of the thalamus through the sublenticular portion of the internal capsule to the calcarine occipital cortex (striate area). Synonym: geniculocalcarine tract

photochemical radiation

Light rays that penetrate tissues only fractions of a millimeter, are absorbed by cells, and cause physical and biological changes. This type of radiation causes surface heating.

photothermal radiation

Radiation of heat by a source of light, as that from an electric bulb.

primary radiation

That radiation being emitted directly to the patient from an x-ray source.

pyramidal radiation

The radiation of fibers from the cerebral cortex to the pyramidal tract.

remnant radiation

Ionizing radiation that passes through the part being examined to make the radiographical image.

scattered radiation

X-rays that have changed direction because of a collision with matter.

secondary radiation

X-rays produced by the interaction between primary radiation and the substance being radiated.

solar radiation

Radiation from the sun; 60% is infrared and 40% is visible and ultraviolet.

spatially fractionated radiation

Abbreviation: SFR
Radiation treatment applied in high doses to a large tumor through a grid designed to direct energy into multiple discrete regions of the mass.

striatomesencephalic radiation

Fibers originating in the corpus striatum and terminating principally in the substantia nigra of the midbrain.

striatosubthalamic radiation

A system of fibers consisting of three groups that emerge from the medial aspect of the lentiform nucleus and enter the subthalamic region, most terminating there but some continuing into the midbrain. Synonym: ansa lenticularis

striatothalamic radiation

Groups of fibers connecting the corpus striatum with the thalamus and subthalamus.

synchrotron radiation

Radiation released by charged particles accelerated by a synchrotron. It may be used to obtain noninvasive images of body structures (e.g., the coronary arteries) or to study the structure of proteins, tissue samples, or other objects of biological or medical interest.

thalamic radiation

Groups of fibers connecting the thalamus with the cerebral hemispheres. These include frontal, centroparietal, occipital, and optic radiations.

thermal radiation

Heat radiation.

ultraviolet radiation

Radiant energy extending from 3900 to 200 angstrom units (A.U.) Divided into near ultraviolet, which extends from 3900 to 2900 A.U., and far ultraviolet, which extends from 2900 to 200 A.U.

visible radiation

The radiation of the visible spectrum, which may be broken up into different wavelengths representing different colors:

Violet, 3900–4550 angstrom units (A.U.)

Blue, 4550–4920 A.U.

Green, 4920–5770 A.U.

Yellow, 5770–5970 A.U.

Orange, 5970–6220 A.U.

Red, 6220–7700 A.U.

x radiation

1. A form of electromagnetic radiation with wavelengths in the range of 0.01 to 10 nm, frequencies from 3 × 1016 Hz to 3 × 1019 Hz, and energies in the range 120 eV to 120 keV.
2. Treatment with or exposure to x-rays.

radiation

1. divergence from a common center.
2. a structure made up of diverging elements, especially a tract of the central nervous system made up of diverging fibers.
3. energy carried by waves or a stream of particles. One type is electromagnetic radiation, which consists of wave motion of electric and magnetic fields. The quantum theory is based on the fact that electromagnetic waves consist of discrete particles, called photons, that have an energy inversely proportional to the wavelength of the wave. In order of increasing photon energy and decreasing wavelength, the electromagnetic spectrum is divided into radio waves, infrared light, visible light, ultraviolet light and x-rays.
Another type is the radiation emitted by radioactive materials. Alpha particles are high-energy helium-4 nuclei consisting of two protons and two neutrons, which are emitted by radioisotopes of heavy elements, such as uranium. Beta particles are high-energy electrons, which are emitted by radioisotopes of lighter elements. Gamma rays are high-energy photons, which are emitted along with alpha and beta particles and are also emitted alone by metastable radionuclides, such as technetium-99m. Gamma rays have energies in the x-ray region of the spectrum and differ from x-rays only in that they are produced by radioactive decay rather than by x-ray machines.
Radiation with enough energy to knock electrons out of atoms and produce ions is called ionizing radiation. This includes alpha and beta particles and x-rays and gamma rays.

radiation biology
study of the effects of ionizing radiation on living tissues.
corpuscular radiation
particles emitted in nuclear disintegration, including alpha and beta particles, protons, neutrons, positrons and deuterons.
radiation detection
special equipment, including Geiger-Müller tubes and a scintillation crystal, is available to detect radiation which may be accidental, or detect small amounts where this is expected but it needs to be measured in terms of accumulated dose.
electromagnetic radiation
energy, unassociated with matter, that is transmitted through space by means of waves (electromagnetic waves) traveling in all instances at 3 × 1010 cm or 186,284 miles per second, but ranging in length from 1011 cm (electrical waves) to 10−12 cm (cosmic rays) and including radio waves, infrared, visible light and ultraviolet, x-rays and gamma rays.
radiation exposure
means more than the patient being exposed intentionally to an x-ray beam. Technical persons in the vicinity will also be exposed to a much less dangerous but perniciously cumulative load of radiation.
infrared radiation
the portion of the spectrum of electromagnetic radiation of wavelengths ranging between 0.75 and 1000 μm. See also infrared.
radiation injury
is caused by exposure to radioactive material. High doses cause intense diarrhea and dehydration and extensive skin necrosis. Median doses cause initial anorexia, lethargy and vomiting then normality for several weeks followed by vomiting, nasal discharge, dysentery, recumbency, septicemia and a profound pancytopenia. Death is the most common outcome. Chronic doses cause cataract in a few. Congenital defects occur rarely.
interstitial radiation
energy emitted by radium or radon inserted directly into the tissue.
ionizing radiation
corpuscular or electromagnetic radiation that is capable of producing ions, directly or indirectly, in its passage through matter. Used in treatment of radiosensitive cancer, in sterilization of animal products and food for experimental use.
radiation necrosis
see radionecrosis.
radiation physicist
the person responsible for the administration of radiation therapy including estimating the dose required for a treatment, arranging for the dose to be delivered and making arrangements for safety of the patient and staff, and disposing of any residual radioactive material. Technical aspects of the work include computer estimations, preparation of isodose curves, preparation of wedge and compensating filters, and calibration of teletherapy equipment.
primary radiation
radiation emanating from the x-ray tube which is absorbed by the subject or passes on through the subject without any change in photon energy.
radiation protection
includes proper control of emissions from the x-ray machines, proper protective clothing for staff, keeping unnecessary people out of the way while the tube is actually generating its beam, the wearing and regular examination of a dosimeter and the proper storage of radioactive materials or residues.
pyramidal radiation
fibers extending from the pyramidal tract to the cortex.
radiation sensitivity
tissues vary in their sensitivity to the damaging effects of irradiation. The rapidly growing tissues are most susceptible, e.g. the embryo, rapidly growing cancer, gonads, alimentary tract, skin and blood-forming organs.
radiation sickness
see radiation injury (above).
solar radiation
see solar.
radiation striothalamica
a fiber system joining the thalamus and the hypothalamic region.
tegmental radiation
fibers radiating laterally from the nucleus ruber.
thalamic radiation
fibers streaming out through the lateral surface of the thalamus, through the internal capsule to the cerebral cortex.
radiation therapist
a person skilled in radiotherapy. See also radiation therapy (below).
radiation therapy
ultraviolet radiation
the portion of the spectrum of electromagnetic radiation of wavelengths ranging between 0.39 and 0.18 μm. See also ultraviolet rays.
References in periodicals archive ?
Provision was made in the dryer so that both the infrared radiation intensity and the air temperature could be varied by regulating the voltage through a power regulator.
Based on the data presented, the authors recommend that the use of artificial infrared radiation devices such as those used in this study is unethical and should be legally restricted.
The sub capsular opacity typically seen as a result of infrared radiation exposure is also exactly the same histologically as that seen as a result of other types of radiation-induced cataract, such as those from X-ray, atomic bomb (from [beta] and [gamma] rays) and cyclotron exposure (neutrons).
Preliminary measurements indicate that the microhotplate structure may be a useful infrared radiation calibration artifact for very small heat sources where the accuracy of the temperature measurement is affected by spatial resolution.
Scientists believe that rising concentrations of methane, which absorbs and sends infrared radiation to the Earth, are contributing to global warming.
When a beam of infrared radiation is passed through a sample, the transmittance or absorption as a function of frequency or wavelength is measured to determine a sample's composition.
The lesson plan concerning ultraviolet, visible, and infrared radiation, discusses: the fundamentals of the radiation; biological effects and hazards; standards and laws which regulate exposures; evaluation of hazards; and protection and control steps to be taken.
Actually, carbon dioxide traps heat from the sun that would otherwise escape by infrared radiation.
Infrared sensing works by translating the amount of infrared radiation that is emitted by the warm bubble into temperature readings.
In what is called a 'kinetic kill,' our reliable seeker detects infrared radiation from the target missile and warhead and generates video guiding the interceptor to the target," said Barry Yeadon, THAAD program manager at BAE Systems.
Tenders are invited for reference infrared radiation pyrometer - 1 pcs .
It was thought that most of the strong infrared radiation coming from AGN originated in these doughnuts.

Full browser ?