List of radiation topics - AbsoluteAstronomy.com

absorbed dose
Absorbed dose
Absorbed dose is a measure of the energy deposited in a medium by ionizing radiation per unit mass...
equivalent dose
Equivalent dose
The equivalent absorbed radiation dose, usually shortened to equivalent dose, is a computed average measure of the radiation absorbed by a fixed mass of biological tissue, that attempts to account for the different biological damage potential of different types of ionizing radiation...
hormesis
Hormesis
Hormesis is the term for generally favorable biological responses to low exposures to toxins and other stressors. A pollutant or toxin showing hormesis thus has the opposite effect in small doses as in large doses...
Louis Harold Gray
Louis Harold Gray
Louis Harold Gray was a British physicist who worked mainly on the effects of radiation on biological systems, inventing the field of radiobiology as he went. A summary of his work is given below...

(British physicist)
rad (unit)
Rad (unit)
The rad is a unit of absorbed radiation dose. The rad was first proposed in 1918 as "that quantity of X rays which when absorbed will cause the destruction of the malignant mammalian cells in question..." It was defined in CGS units in 1953 as the dose causing 100 ergs of energy to be absorbed by...
radar
Radar
Radar is an object-detection system which uses radio waves to determine the range, altitude, direction, or speed of objects. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, weather formations, and terrain. The radar dish or antenna transmits pulses of radio...
radar astronomy
Radar astronomy
Radar astronomy is a technique of observing nearby astronomical objects by reflecting microwaves off target objects and analyzing the echoes. This research has been conducted for six decades. Radar astronomy differs from radio astronomy in that the latter is a passive observation and the former an...
radar cross section
Radar cross section
Radar cross section is a measure of how detectable an object is with a radar. A larger RCS indicates that an object is more easily detected.An object reflects a limited amount of radar energy...
radar detector
Radar detector
A radar detector is an electronic device used by motorists to detect if their speed is being monitored by police or law enforcement using a radar gun. Most radar detectors are used so the driver can reduce the car's speed before being ticketed for speeding...
radar gun
Radar gun
A radar speed gun is a small doppler radar unit used to measure the speed of moving objects, including vehicles, pitched baseballs, runners and other moving objects. Radar speed guns may be hand-held, vehicle-mounted or static...
radar jamming
(radar reflector) corner reflector
Corner reflector
A corner reflector is a retroreflector consisting of three mutually perpendicular, intersecting flat surfaces, which reflects waves back directly towards the source, but shifted . Unlike a simple mirror, they work for a relatively wide-angle field of view. The three intersecting surfaces often have...
radar warning receiver
Radar warning receiver
Radar warning receiver systems detect the radio emissions of radar systems. Their primary purpose is to issue a warning when a radar signal that might be a threat is detected. The warning can then be used, manually or automatically, to evade the detected threat...
(Radarange) microwave oven
Microwave oven
A microwave oven is a kitchen appliance that heats food by dielectric heating, using microwave radiation to heat polarized molecules within the food...
radiance
Radiance
Radiance and spectral radiance are radiometric measures that describe the amount of radiation such as light or radiant heat that passes through or is emitted from a particular area, and falls within a given solid angle in a specified direction. They are used to characterize both emission from...
(radiant: see) meteor shower
Meteor shower
A meteor shower is a celestial event in which a number of meteors are observed to radiate from one point in the night sky. These meteors are caused by streams of cosmic debris called meteoroids entering Earth's atmosphere at extremely high speeds on parallel trajectories. Most meteors are smaller...
radiation
Radiation
In physics, radiation is a process in which energetic particles or energetic waves travel through a medium or space. There are two distinct types of radiation; ionizing and non-ionizing...
radiation angle
Radiation angle
In fiber optics, the radiation angle is half the vertex angle of the cone of light emitted at the exit face of an optical fiber.The cone boundary is usually defined by the angle at which the far-field irradiance has decreased to a specified fraction of its maximum value or as the cone within...
radiant barrier
Radiant barrier
Radiant barriers or reflective barriers inhibit heat transfer by thermal radiation. Thermal energy may also be transferred via conduction or convection, however, and radiant barriers do not necessarily protect against heat transfer via conduction or convection....
(radiation belt: see) Van Allen radiation belt
Van Allen radiation belt
The Van Allen radiation belt is a torus of energetic charged particles around Earth, which is held in place by Earth's magnetic field. It is believed that most of the particles that form the belts come from solar wind, and other particles by cosmic rays. It is named after its discoverer, James...
radiation budget
(radiation contamination) radioactive contamination
Radioactive contamination
Radioactive contamination, also called radiological contamination, is radioactive substances on surfaces, or within solids, liquids or gases , where their presence is unintended or undesirable, or the process giving rise to their presence in such places...
radiant energy
Radiant energy
Radiant energy is the energy of electromagnetic waves. The quantity of radiant energy may be calculated by integrating radiant flux with respect to time and, like all forms of energy, its SI unit is the joule. The term is used particularly when radiation is emitted by a source into the...
(radiation exposure) radioactive contamination
Radioactive contamination
Radioactive contamination, also called radiological contamination, is radioactive substances on surfaces, or within solids, liquids or gases , where their presence is unintended or undesirable, or the process giving rise to their presence in such places...
(radiation gauge: see) gauge fixing
Gauge fixing
In the physics of gauge theories, gauge fixing denotes a mathematical procedure for coping with redundant degrees of freedom in field variables. By definition, a gauge theory represents each physically distinct configuration of the system as an equivalence class of detailed local field...
radiation hardening
Radiation hardening
Radiation hardening is a method of designing and testing electronic components and systems to make them resistant to damage or malfunctions caused by ionizing radiation , such as would be encountered in outer space, high-altitude flight, around nuclear reactors, particle accelerators, or during...
(radiant heat) thermal radiation
Thermal radiation
Thermal radiation is electromagnetic radiation generated by the thermal motion of charged particles in matter. All matter with a temperature greater than absolute zero emits thermal radiation....
radiant heating
Radiant heating
Radiant heating is a technology for heating indoor and outdoor areas. Heating by radiant energy is observed everyday, the warmth of the sunshine being probably the most commonly observed example. Radiant heating as a technology is typically more narrowly defined...
radiant intensity
Radiant intensity
In radiometry, radiant intensity is a measure of the intensity of electromagnetic radiation. It is defined as power per unit solid angle. The SI unit of radiant intensity is watts per steradian . Radiant intensity is distinct from irradiance and radiant exitance, which are often called intensity...
radiation hormesis
Radiation hormesis
Radiation hormesis is the hypothesis that low doses of ionizing radiation are beneficial, stimulating the activation of repair mechanisms that protect against disease, that are not activated in absence of ionizing radiation...
radiation impedance
Radiation impedance
In acoustics, radiation impedance is the impedance of any vibrating solid or fluid that radiates sound in the surrounding medium.-See also:*Acoustic impedance...
radiation implosion
Radiation implosion
The term radiation implosion describes the process behind a class of devices which use high levels of electromagnetic radiation to compress a target...
Radiation Laboratory
Radiation Laboratory
The Radiation Laboratory, commonly called the Rad Lab, was located at the Massachusetts Institute of Technology in Cambridge, Massachusetts and functioned from October 1940 until December 31, 1945...
radiation length
Radiation length
In physics, the radiation length is a characteristic of a material, related to the energy loss of high energy, electromagnetic-interacting particles with it.-Definition:High-energy electrons predominantly lose energy in matter...
radiation mode
radiation oncologist
Radiation oncologist
A radiation oncologist is a doctor who specializes in the treatment of cancer patients, using radiation therapy as the main modality of treatment. Radiation can be given as a curative modality, either alone or in combination with surgery and/or chemotherapy. It may also be used palliatively, to...
radiation pattern
Radiation pattern
In the field of antenna design the term radiation pattern most commonly refers to the directional dependence of the strength of the radio waves from the antenna or other source ....
radiation poisoning
Radiation poisoning
Acute radiation syndrome also known as radiation poisoning, radiation sickness or radiation toxicity, is a constellation of health effects which occur within several months of exposure to high amounts of ionizing radiation...

(radiation sickness)
radiation pressure
Radiation pressure
Radiation pressure is the pressure exerted upon any surface exposed to electromagnetic radiation. If absorbed, the pressure is the power flux density divided by the speed of light...
radiation protection (radiation shield) (radiation shielding)
radiation resistance
Radiation resistance
Radiation resistance is that part of an antenna's feedpoint resistance that is caused by the radiation of electromagnetic waves from the antenna. The radiation resistance is determined by the geometry of the antenna, not by the materials of which it is made...
Radiation Safety Officer
Radiation Safety Officer
In the United States, the person within an organization responsible for the safe use of radiation and radioactive materials as well as regulatory compliance...
radiation scattering
radiation therapist
Radiation therapist
The Radiation Therapist is an allied health professional who works in the field of radiation oncology...
radiation therapy
Radiation therapy
Radiation therapy , radiation oncology, or radiotherapy , sometimes abbreviated to XRT or DXT, is the medical use of ionizing radiation, generally as part of cancer treatment to control malignant cells.Radiation therapy is commonly applied to the cancerous tumor because of its ability to control...

(radiotherapy)
(radiation treatment) radiation therapy
Radiation therapy
Radiation therapy , radiation oncology, or radiotherapy , sometimes abbreviated to XRT or DXT, is the medical use of ionizing radiation, generally as part of cancer treatment to control malignant cells.Radiation therapy is commonly applied to the cancerous tumor because of its ability to control...
(radiation units: see) :Category:Units of radiation dose
(radiation weight factor: see) equivalent dose
Equivalent dose
The equivalent absorbed radiation dose, usually shortened to equivalent dose, is a computed average measure of the radiation absorbed by a fixed mass of biological tissue, that attempts to account for the different biological damage potential of different types of ionizing radiation...
radiation zone
Radiation zone
The radiation zone is the middle zone in the Sun's interior. Energy travels out of the core into the radiation zone. Energy that travels through the radiation zone is in the form of electromagnetic radiation. The radiation zone is so dense that the waves bounce around...
radiative cooling
Radiative cooling
Radiative cooling is the process by which a body loses heat by thermal radiation.- Earth's energy budget :In the case of the earth-atmosphere system it refers to the process by which long-wave radiation is emitted to balance the absorption of short-wave energy from the sun.The exact process by...
radiative forcing
Radiative forcing
In climate science, radiative forcing is generally defined as the change in net irradiance between different layers of the atmosphere. Typically, radiative forcing is quantified at the tropopause in units of watts per square meter. A positive forcing tends to warm the system, while a negative...
radiator
Radiator
Radiators are heat exchangers used to transfer thermal energy from one medium to another for the purpose of cooling and heating. The majority of radiators are constructed to function in automobiles, buildings, and electronics...
radio
Radio
Radio is the transmission of signals through free space by modulation of electromagnetic waves with frequencies below those of visible light. Electromagnetic radiation travels by means of oscillating electromagnetic fields that pass through the air and the vacuum of space...
(radio amateur: see) amateur radio
Amateur radio
Amateur radio is the use of designated radio frequency spectrum for purposes of private recreation, non-commercial exchange of messages, wireless experimentation, self-training, and emergency communication...
(radio antenna) antenna (radio)
Antenna (radio)
An antenna is an electrical device which converts electric currents into radio waves, and vice versa. It is usually used with a radio transmitter or radio receiver...
radio astronomy
Radio astronomy
Radio astronomy is a subfield of astronomy that studies celestial objects at radio frequencies. The initial detection of radio waves from an astronomical object was made in the 1930s, when Karl Jansky observed radiation coming from the Milky Way. Subsequent observations have identified a number of...
radio beacon
(radio broadcasting: see) broadcasting
Broadcasting
Broadcasting is the distribution of audio and video content to a dispersed audience via any audio visual medium. Receiving parties may include the general public or a relatively large subset of thereof...
radio clock
Radio clock
A radio clock or radio-controlled clock is a clock that is synchronized by a time code bit stream transmitted by a radio transmitter connected to a time standard such as an atomic clock...
(radio communications) radio
Radio
Radio is the transmission of signals through free space by modulation of electromagnetic waves with frequencies below those of visible light. Electromagnetic radiation travels by means of oscillating electromagnetic fields that pass through the air and the vacuum of space...
radio control
Radio control
Radio control is the use of radio signals to remotely control a device. The term is used frequently to refer to the control of model vehicles from a hand-held radio transmitter...
radio controlled airplane
radio controlled car
radio controlled helicopter
radio controlled model
(radio controlled plane) model aircraft
Model aircraft
Model aircraft are flying or non-flying models of existing or imaginary aircraft using a variety of materials including plastic, diecast metal, polystyrene, balsa wood, foam and fibreglass...

(see under Powered models)
(radio crystal oscillator) crystal oscillator
Crystal oscillator
A crystal oscillator is an electronic oscillator circuit that uses the mechanical resonance of a vibrating crystal of piezoelectric material to create an electrical signal with a very precise frequency...
(radio detection and ranging) radar
Radar
Radar is an object-detection system which uses radio waves to determine the range, altitude, direction, or speed of objects. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, weather formations, and terrain. The radar dish or antenna transmits pulses of radio...
radio direction finder
Radio direction finder
A radio direction finder is a device for finding the direction to a radio source. Due to low frequency propagation characteristic to travel very long distances and "over the horizon", it makes a particularly good navigation system for ships, small boats, and aircraft that might be some distance...

(RDF)
radio electronics
Radio electronics
*For the magazine, see Radio-ElectronicsRadio electronics is the sub-field of electrical engineering concerning itself with the class of electronic circuits which receive or transmit radio signals....
Radio Emergency Associated Communication Teams
Radio Emergency Associated Communication Teams
REACT began as a CB radio Emergency Channel 9 monitoring organization across the United States and Canada in 1962. Initially, the primary role of REACT volunteers was to monitor Channel 9, the CB Emergency Channel, to help motorists. Later, duties grew to include communications after disasters ,...
radio equipment
Radio equipment
Radio equipment, as defined in Federal Information Management Regulations, is any equipment or interconnected system or subsystem of equipment that is used to communicate over a distance by modulating and radiating electromagnetic waves in space without artificial guide...
radio fingerprinting
Radio fingerprinting
Radio fingerprinting is a process that identifies a cellular phone or any other radio transmitter by the unique "fingerprint" that characterizes its signal transmission. An electronic fingerprint makes it possible to identify a wireless device by its unique radio transmission characteristics. Radio...
radio fix
Radio fix
In telecommunication and position fixing, the term radio fix has the following meanings:*The locating of a radio transmitter by bearings taken from two or more direction finding stations, the site of the transmitter being at the point of intersection....
radio frequency
Radio frequency
Radio frequency is a rate of oscillation in the range of about 3 kHz to 300 GHz, which corresponds to the frequency of radio waves, and the alternating currents which carry radio signals...

(RF)
radio frequency engineering
Radio frequency engineering
Radio frequency engineering is the analysis and design of circuits at frequencies where transmission lines are comparable to the wavelength. It includes the study of amplifiers, oscillators, mixers, demodulators and antennas. This is relevant to RFID, broadcasting, radar, wireless computer...
radio frequency interference (RFI)
(radio galaxy: see) active galaxy
(radio ham: see) amateur radio
Amateur radio
Amateur radio is the use of designated radio frequency spectrum for purposes of private recreation, non-commercial exchange of messages, wireless experimentation, self-training, and emergency communication...
(radio history) history of radio
History of radio
The early history of radio is the history of technology that produced radio instruments that use radio waves. Within the timeline of radio, many people contributed theory and inventions in what became radio. Radio development began as "wireless telegraphy"...
radio horizon
radio identification tag
radio jamming
Radio jamming
Radio jamming is the transmission of radio signals that disrupt communications by decreasing the signal to noise ratio. Unintentional jamming occurs when an operator transmits on a busy frequency without first checking whether it is in use, or without being able to hear stations using the frequency...
radio masts and towers
Radio masts and towers
Radio masts and towers are, typically, tall structures designed to support antennas for telecommunications and broadcasting, including television. They are among the tallest man-made structures...
(radio mesh network) wireless mesh network
Wireless mesh network
A wireless mesh network is a communications network made up of radio nodes organized in a mesh topology. Wireless mesh networks often consist of mesh clients, mesh routers and gateways.The mesh clients are often laptops, cell phones and other wireless devices while the mesh routers forward traffic...
radio navigation
Radio navigation
Radio navigation or radionavigation is the application of radio frequencies to determine a position on the Earth. Like radiolocation, it is a type of radiodetermination.The basic principles are measurements from/to electric beacons, especially...
radio noise source
Radio noise source
A radio noise source is a device that emits radio waves at a certain frequency, used to calibrate radio telescopes such that received data may be compared to a known value, as well as to find the focal point of a telescope soon after construction, so that the wave guide and front end may be...
radio propagation
Radio propagation
Radio propagation is the behavior of radio waves when they are transmitted, or propagated from one point on the Earth to another, or into various parts of the atmosphere...
(radio pulsar: see) rotation-powered pulsar
(radio receiver) receiver (radio)
Receiver (radio)
A radio receiver converts signals from a radio antenna to a usable form. It uses electronic filters to separate a wanted radio frequency signal from all other signals, the electronic amplifier increases the level suitable for further processing, and finally recovers the desired information through...
(radio relay link: see) microwave radio relay
(radio scanner) scanner (radio)
Scanner (radio)
A scanner is a radio receiver that can automatically tune, or scan, two or more discrete frequencies, stopping when it finds a signal on one of them and then continuing to scan other frequencies when the initial transmission ceases....
radio source
Radio source
Radio sources are objects in outer space that emit strong radio waves. Radio emission comes from a wide variety of sources. Such objects represent some of the most extreme and energetic physical processes in the universe.-History:...
radio source SHGb02 plus 14a
(radio spectrum: see) radio frequency
Radio frequency
Radio frequency is a rate of oscillation in the range of about 3 kHz to 300 GHz, which corresponds to the frequency of radio waves, and the alternating currents which carry radio signals...
radio spectrum pollution
Radio spectrum pollution
Radio spectrum pollution is the straying of waves in the radio and electromagnetic spectrums outside their allocations that cause problems for some activities. It is of particular concern to radio astronomers....
radio star
Radio star
Stellar radio sources, radio source stars or radio stars are stellar objects that produce copious emissions of various radio frequencies, whether constant or pulsed. Radio emissions from stars can be produced in many varied ways....
radio station
Radio station
Radio broadcasting is a one-way wireless transmission over radio waves intended to reach a wide audience. Stations can be linked in radio networks to broadcast a common radio format, either in broadcast syndication or simulcast or both...
(Radio Technical Commission for Aeronautics]] (RTCA)
(radio telegraphy) wireless telegraphy
Wireless telegraphy
Wireless telegraphy is a historical term used today to apply to early radio telegraph communications techniques and practices, particularly those used during the first three decades of radio before the term radio came into use....
(radio telephone) radiotelephone
Radiotelephone
A radiotelephone is a communications system for transmission of speech over radio. Radiotelephone systems are not necessarily interconnected with the public "land line" telephone network. "Radiotelephone" is often used to describe the usage of radio spectrum where it is important to distinguish the...
radio telescope
Radio telescope
A radio telescope is a form of directional radio antenna used in radio astronomy. The same types of antennas are also used in tracking and collecting data from satellites and space probes...
(radio teletype) radioteletype
Radioteletype
Radioteletype is a telecommunications system consisting originally of two or more electromechanical teleprinters in different locations, later superseded by personal computers running software to emulate teleprinters, connected by radio rather than a wired link.The term radioteletype is used to...

(RTTY)
(radio tower: see) radio masts and towers
Radio masts and towers
Radio masts and towers are, typically, tall structures designed to support antennas for telecommunications and broadcasting, including television. They are among the tallest man-made structures...
(radio translator) broadcast translator
(radio transmission) transmission (telecommunications)
Transmission (telecommunications)
Transmission, in telecommunications, is the process of sending, propagating and receiving an analogue or digital information signal over a physical point-to-point or point-to-multipoint transmission medium, either wired, optical fiber or wireless...
(radio transmitter: see) transmitter
Transmitter
In electronics and telecommunications a transmitter or radio transmitter is an electronic device which, with the aid of an antenna, produces radio waves. The transmitter itself generates a radio frequency alternating current, which is applied to the antenna. When excited by this alternating...
(radio tube triode: see) vacuum tube
Vacuum tube
In electronics, a vacuum tube, electron tube , or thermionic valve , reduced to simply "tube" or "valve" in everyday parlance, is a device that relies on the flow of electric current through a vacuum...

(thermionic valve)
(radio tuner) tuner (radio)
Tuner (radio)
A radio tuner is a subsystem that receives radio broadcasts and converts them into audio-frequency signals which can be fed into an amplifier driving a loudspeaker. FM tuner, AM tuner, Digital Audio Broadcasting DAB tuner, etc. are types of radio tuner dealing with transmissions using different...
(radio wave: see) radio frequency
Radio frequency
Radio frequency is a rate of oscillation in the range of about 3 kHz to 300 GHz, which corresponds to the frequency of radio waves, and the alternating currents which carry radio signals...

(RF)
radio window
Radio window
The radio window is the range of frequencies of electromagnetic radiation that the earth's atmosphere lets through. The wavelengths in the radio window run from about one centimetre to about eleven-metre waves.-See also:*Astronomical window...
radio-frequency induction
Radio-frequency induction
Radio-frequency induction or RF induction is the use of a radio frequency magnetic field to transfer energy by means of electromagnetic induction in the near field...
(radio-jet x-ray binariy: see) microquasar
(radio-to-radio: see) repeater
Repeater
A repeater is an electronic device that receives asignal and retransmits it at a higher level and/or higher power, or onto the other side of an obstruction, so that the signal can cover longer distances.-Description:...
(radioactive boy scout) David Hahn
David Hahn
David Charles Hahn , also called the "Radioactive Boy Scout" or the "Nuclear Boy Scout", is an American who attempted to build a homemade breeder nuclear reactor in 1994, at age 17. A scout in the Boy Scouts of America, Hahn conducted his experiments in secret in a backyard shed at his mother's...
(radioactive cloud: see) nuclear fallout
Nuclear fallout
Fallout is the residual radioactive material propelled into the upper atmosphere following a nuclear blast, so called because it "falls out" of the sky after the explosion and shock wave have passed. It commonly refers to the radioactive dust and ash created when a nuclear weapon explodes...
radioactive contamination
Radioactive contamination
Radioactive contamination, also called radiological contamination, is radioactive substances on surfaces, or within solids, liquids or gases , where their presence is unintended or undesirable, or the process giving rise to their presence in such places...

(radioactive exposure)
(radioactive dating) radiometric dating
Radiometric dating
Radiometric dating is a technique used to date materials such as rocks, usually based on a comparison between the observed abundance of a naturally occurring radioactive isotope and its decay products, using known decay rates...
radioactive decay
Radioactive decay
Radioactive decay is the process by which an atomic nucleus of an unstable atom loses energy by emitting ionizing particles . The emission is spontaneous, in that the atom decays without any physical interaction with another particle from outside the atom...
radioactive decay path
(radioactive dust: see) nuclear fallout
Nuclear fallout
Fallout is the residual radioactive material propelled into the upper atmosphere following a nuclear blast, so called because it "falls out" of the sky after the explosion and shock wave have passed. It commonly refers to the radioactive dust and ash created when a nuclear weapon explodes...
(radioactive exposure) radioactive contamination
Radioactive contamination
Radioactive contamination, also called radiological contamination, is radioactive substances on surfaces, or within solids, liquids or gases , where their presence is unintended or undesirable, or the process giving rise to their presence in such places...
Radioactive Incident Monitoring Network
Radioactive Incident Monitoring Network
The Radioactive Incident Monitoring Network is a network of 91 monitoring stations, used by the Government of the United Kingdom which records and analyses the level of radioactivity across the United Kingdom...

(RIMNET) (in the UK)
(radioactive isotope) radionuclide
Radionuclide
A radionuclide is an atom with an unstable nucleus, which is a nucleus characterized by excess energy available to be imparted either to a newly created radiation particle within the nucleus or to an atomic electron. The radionuclide, in this process, undergoes radioactive decay, and emits gamma...
radioactive quackery
Radioactive quackery
Radioactive quackery refers to various products sold during the early 20th century, after the discovery of radioactivity, which promised radioactivity as a cure for various illnesses...
(radioactive radiation: see) radiation
Radiation
In physics, radiation is a process in which energetic particles or energetic waves travel through a medium or space. There are two distinct types of radiation; ionizing and non-ionizing...
radioactive tracer
Radioactive tracer
A radioactive tracer, also called a radioactive label, is a substance containing a radioisotope that is used to measure the speed of chemical processes and to track the movement of a substance through a natural system such as a cell or tissue...
radioactive waste
Radioactive waste
Radioactive wastes are wastes that contain radioactive material. Radioactive wastes are usually by-products of nuclear power generation and other applications of nuclear fission or nuclear technology, such as research and medicine...
(radioactivity) radioactive decay
Radioactive decay
Radioactive decay is the process by which an atomic nucleus of an unstable atom loses energy by emitting ionizing particles . The emission is spontaneous, in that the atom decays without any physical interaction with another particle from outside the atom...
(radioastronomy) radio astronomy
Radio astronomy
Radio astronomy is a subfield of astronomy that studies celestial objects at radio frequencies. The initial detection of radio waves from an astronomical object was made in the 1930s, when Karl Jansky observed radiation coming from the Milky Way. Subsequent observations have identified a number of...
radiobiology
Radiobiology
Radiobiology , as a field of clinical and basic medical sciences, originated from Leopold Freund's 1896 demonstration of the therapeutic treatment of a hairy mole using a new type of electromagnetic radiation called x-rays, which was discovered 1 year previously by the German physicist, Wilhelm...
(radiocarbon) carbon-14
Carbon-14
Carbon-14, 14C, or radiocarbon, is a radioactive isotope of carbon with a nucleus containing 6 protons and 8 neutrons. Its presence in organic materials is the basis of the radiocarbon dating method pioneered by Willard Libby and colleagues , to date archaeological, geological, and hydrogeological...
radiocarbon dating
Radiocarbon dating
Radiocarbon dating is a radiometric dating method that uses the naturally occurring radioisotope carbon-14 to estimate the age of carbon-bearing materials up to about 58,000 to 62,000 years. Raw, i.e. uncalibrated, radiocarbon ages are usually reported in radiocarbon years "Before Present" ,...

(radiocarbon test)
radiocarbon revolution
radiocarbon year
radiochemistry
Radiochemistry
Radiochemistry is the chemistry of radioactive materials, where radioactive isotopes of elements are used to study the properties and chemical reactions of non-radioactive isotopes...
(radiocommunication: see) radio
Radio
Radio is the transmission of signals through free space by modulation of electromagnetic waves with frequencies below those of visible light. Electromagnetic radiation travels by means of oscillating electromagnetic fields that pass through the air and the vacuum of space...
Radiocommunications Agency
radiocontrast
Radiocontrast
Radiocontrast agents are a type of medical contrast medium used to improve the visibility of internal bodily structures in an X-ray based imaging techniques such as computed tomography or radiography...
radiodensity
Radiodensity
Radiodensity refers to the relative inability of electromagnetic radiation, particularly X-rays, to pass through a particular material. Radiolucency indicates greater transparency or "transradiancy" to X-ray photons...
radiodetermination
Radiodetermination
As defined by FS-1037C, radiodetermination is the determination of the position, velocity or other characteristics of an object, or the obtaining of information relating to these parameters, by means of the propagation properties of radio waves....
radiofax
Radiofax
Radiofax, also known as weatherfax and HF fax , is an analogue mode for transmitting monochrome images. It was the predecessor to slow-scan television...

(HF Fax)
(radiofluorescence) radioluminescence
Radioluminescence
Radioluminescence is the phenomenon by which luminescence is produced in a material by the bombardment of ionizing radiation such as beta particles.-Tritium:...
(radiofrequency) radio frequency
Radio frequency
Radio frequency is a rate of oscillation in the range of about 3 kHz to 300 GHz, which corresponds to the frequency of radio waves, and the alternating currents which carry radio signals...
radiogenic
radiographer
radiohalo
Radiohalo
Radiohalos or pleochroic halos are microscopic, spherical shells of discolouration within minerals such as biotite that occur in granite and other igneous rocks. The shells are zones of radiation damage caused by the inclusion of minute radioactive crystals within the host crystal structure...
radioimmunoassay
Radioimmunoassay
Radioimmunoassay is a very sensitive in vitro assay technique used to measure concentrations of antigens by use of antibodies...
(radioiodine) iodine-131
Iodine-131
Iodine-131 , also called radioiodine , is an important radioisotope of iodine. It has a radioactive decay half-life of about eight days. Its uses are mostly medical and pharmaceutical...
(radioisotope) radionuclide
Radionuclide
A radionuclide is an atom with an unstable nucleus, which is a nucleus characterized by excess energy available to be imparted either to a newly created radiation particle within the nucleus or to an atomic electron. The radionuclide, in this process, undergoes radioactive decay, and emits gamma...
radioisotope thermoelectric generator
Radioisotope thermoelectric generator
A radioisotope thermoelectric generator is an electrical generator that obtains its power from radioactive decay. In such a device, the heat released by the decay of a suitable radioactive material is converted into electricity by the Seebeck effect using an array of thermocouples.RTGs can be...

(RTG)
radioisotope heater units
radioisotope rocket
Radioisotope rocket
The radioisotope rocket is a type of rocket engine that uses the heat generated by the decay of radioactive elements to heat a working fluid, which is then exhausted through a rocket nozzle to produce thrust...
radioisotopic labelling
radioligand
Radioligand
A radioligand is a radioactive biochemical substance that is used for diagnosis or for research-oriented study of the receptor systems of the body....
radiolocation
Radiolocation
Radiolocating is the process of finding the location of something through the use of radio waves. It generally refers to passive uses, particularly radar—as well as detecting buried cables, water mains, and other public utilities. It is similar to radionavigation, but radiolocation usually...
Radiological and Environmental Sciences Laboratory
Radiological and Environmental Sciences Laboratory
The Radiological and Environmental Sciences Laboratory is a federally-owned and operated laboratory by the United States Department of Energy located in the Central Facilities Area of the Idaho National Laboratory near Idaho Falls, Idaho...
(radiological bomb) radiological weapon
Radiological weapon
A radiological weapon or radiological dispersion device is any weapon that is designed to spread radioactive material with the intent to kill, and cause disruption upon a city or nation....
(radiological dispersal device) dirty bomb
Dirty bomb
A dirty bomb is a speculative radiological weapon that combines radioactive material with conventional explosives. The purpose of the weapon is to contaminate the area around the explosion with radioactive material, hence the attribute "dirty"....
(Radiological Dispersion Device) radiological weapon
Radiological weapon
A radiological weapon or radiological dispersion device is any weapon that is designed to spread radioactive material with the intent to kill, and cause disruption upon a city or nation....
Radiological Protection Institute of Ireland
Radiological Protection Institute of Ireland
The Radiological Protection Institute of Ireland is an independent public body in the Republic of Ireland under the ageis of the Department of Environment, Heritage and Local Government.The RPII was established in 1992 under the , which conferred on the RPII a broad remit in relation to...

(RPII)
Radiological Society of North America
Radiological Society of North America
The Radiological Society of North America, Inc. is a professional membership society committed to excellence in patient care through education and research...
radiological warfare
Radiological warfare
Radiological warfare is any form of warfare involving deliberate radiation poisoning, without relying on nuclear fission or nuclear fusion.Radiological weapons are normally considered weapons of mass destruction, and are very commonly equated with a radiological bomb often mis-called a "dirty bomb"...
radiological weapon
Radiological weapon
A radiological weapon or radiological dispersion device is any weapon that is designed to spread radioactive material with the intent to kill, and cause disruption upon a city or nation....

(radiological dispersion device [RDD])
radiology
Radiology
Radiology is a medical specialty that employs the use of imaging to both diagnose and treat disease visualized within the human body. Radiologists use an array of imaging technologies to diagnose or treat diseases...
Radiology Information System
Radiology Information System
A radiology information system is a computerized database used by radiology departments to store, manipulate and distribute patient radiological data and imagery. The system generally consists of patient tracking and scheduling, result reporting and image tracking capabilities...

(RIS)
(radiolucent: see) radiodensity
Radiodensity
Radiodensity refers to the relative inability of electromagnetic radiation, particularly X-rays, to pass through a particular material. Radiolucency indicates greater transparency or "transradiancy" to X-ray photons...
radioluminescence
Radioluminescence
Radioluminescence is the phenomenon by which luminescence is produced in a material by the bombardment of ionizing radiation such as beta particles.-Tritium:...

(radiofluorescence)
radiolyse
radiometer
Radiometer
A radiometer is a device for measuring the radiant flux of electromagnetic radiation. Generally, the term radiometer denotes an infrared radiation detector, yet it also includes detectors operating on any electromagnetic wavelength....
(radiometric: see) radiometry
Radiometry
In optics, radiometry is a set of techniques for measuring electromagnetic radiation, including visible light. Radiometric techniques characterize the distribution of the radiation's power in space, as opposed to photometric techniques, which characterize the light's interaction with the human eye...
radiometric dating
Radiometric dating
Radiometric dating is a technique used to date materials such as rocks, usually based on a comparison between the observed abundance of a naturally occurring radioactive isotope and its decay products, using known decay rates...
radiometry
Radiometry
In optics, radiometry is a set of techniques for measuring electromagnetic radiation, including visible light. Radiometric techniques characterize the distribution of the radiation's power in space, as opposed to photometric techniques, which characterize the light's interaction with the human eye...
(radionavigation) radio navigation
Radio navigation
Radio navigation or radionavigation is the application of radio frequencies to determine a position on the Earth. Like radiolocation, it is a type of radiodetermination.The basic principles are measurements from/to electric beacons, especially...
radionuclide
Radionuclide
A radionuclide is an atom with an unstable nucleus, which is a nucleus characterized by excess energy available to be imparted either to a newly created radiation particle within the nucleus or to an atomic electron. The radionuclide, in this process, undergoes radioactive decay, and emits gamma...
(radionuclide computed tomography) single photon emission computed tomography
Single photon emission computed tomography
Single-photon emission computed tomography is a nuclear medicine tomographic imaging technique using gamma rays. It is very similar to conventional nuclear medicine planar imaging using a gamma camera. However, it is able to provide true 3D information...

(SPECT)
(radionuclide test: see) nuclear medicine
Nuclear medicine
In nuclear medicine procedures, elemental radionuclides are combined with other elements to form chemical compounds, or else combined with existing pharmaceutical compounds, to form radiopharmaceuticals. These radiopharmaceuticals, once administered to the patient, can localize to specific organs...
radiodensity
Radiodensity
Radiodensity refers to the relative inability of electromagnetic radiation, particularly X-rays, to pass through a particular material. Radiolucency indicates greater transparency or "transradiancy" to X-ray photons...
radiopharmaceutical
radioresistant
radiosensitivity
Radiosensitivity
Radiosensitivity is the relative susceptibility of cells, tissues, organs or organisms to the harmful effect of ionizing radiation. Cells are least sensitive when in the S phase, then the G1 phase, then G2 phase and the most sensitive in the M phase of the cell cycle...
radiosity
Radiosity
Radiosity is a global illumination algorithm used in 3D computer graphics rendering. Radiosity is an application of the finite element method to solving the rendering equation for scenes with purely diffuse surfaces...
radiosonde
Radiosonde
A radiosonde is a unit for use in weather balloons that measures various atmospheric parameters and transmits them to a fixed receiver. Radiosondes may operate at a radio frequency of 403 MHz or 1680 MHz and both types may be adjusted slightly higher or lower as required...
(radiostation) radio station
Radio station
Radio broadcasting is a one-way wireless transmission over radio waves intended to reach a wide audience. Stations can be linked in radio networks to broadcast a common radio format, either in broadcast syndication or simulcast or both...
radiosurgery
Radiosurgery
Radiosurgery is a medical procedure that allows non-invasive treatment of benign and malignant tumors. It is also known as stereotactic radiotherapy, when used to target lesions in the brain, and stereotactic body radiotherapy when used to target lesions in the body...
(radiotelegraphy) telegraphy
Telegraphy
Telegraphy is the long-distance transmission of messages via some form of signalling technology. Telegraphy requires messages to be converted to a code which is known to both sender and receiver...
radiotelephone
Radiotelephone
A radiotelephone is a communications system for transmission of speech over radio. Radiotelephone systems are not necessarily interconnected with the public "land line" telephone network. "Radiotelephone" is often used to describe the usage of radio spectrum where it is important to distinguish the...
(radiotelescope) radio telescope
Radio telescope
A radio telescope is a form of directional radio antenna used in radio astronomy. The same types of antennas are also used in tracking and collecting data from satellites and space probes...
radioteletype
Radioteletype
Radioteletype is a telecommunications system consisting originally of two or more electromechanical teleprinters in different locations, later superseded by personal computers running software to emulate teleprinters, connected by radio rather than a wired link.The term radioteletype is used to...

(RTTY)
(radiotherapy) radiation therapy
Radiation therapy
Radiation therapy , radiation oncology, or radiotherapy , sometimes abbreviated to XRT or DXT, is the medical use of ionizing radiation, generally as part of cancer treatment to control malignant cells.Radiation therapy is commonly applied to the cancerous tumor because of its ability to control...
(radiothermal generator) radioisotope thermal generator
(radiotoxic: see) ionizing radiation
Ionizing radiation
Ionizing radiation is radiation composed of particles that individually have sufficient energy to remove an electron from an atom or molecule. This ionization produces free radicals, which are atoms or molecules containing unpaired electrons...
radium
Radium
Radium is a chemical element with atomic number 88, represented by the symbol Ra. Radium is an almost pure-white alkaline earth metal, but it readily oxidizes on exposure to air, becoming black in color. All isotopes of radium are highly radioactive, with the most stable isotope being radium-226,...
Radium, Colorado
Radium, Colorado
Radium is a small rural unincorporated community in southwestern Grand County, Colorado, United States. The community sits in the mountains along an isolated stretch of Colorado River downstream from Gore Canyon and southwest of Kremmling. The mainline of the Denver and Rio Grande Western Railroad ...
radium chloride
Radium chloride
Radium chloride, RaCl2, was the first radium compound to be prepared in a pure state and was the basis of Marie Curie's original separation of radium from barium. The first preparation of radium metal was by the electrolysis of a solution of radium chloride using a mercury...
Radium Girls
Radium Girls
The Radium Girls were female factory workers who contracted radiation poisoning from painting watch dials with glow-in-the-dark paint at the United States Radium factory in Orange, New Jersey around 1917....
Radium Hot Springs, British Columbia
Radium Hot Springs, British Columbia
Radium Hot Springs is a village of approximately 800 people situated in the East Kootenay region of British Columbia. The village is named for the hot springs located in the nearby Kootenay National Park...
radon
Radon
Radon is a chemical element with symbol Rn and atomic number 86. It is a radioactive, colorless, odorless, tasteless noble gas, occurring naturally as the decay product of uranium or thorium. Its most stable isotope, 222Rn, has a half-life of 3.8 days...
radon difluoride (see same for "radon fluoride")
relative biological effectiveness
Relative biological effectiveness
In radiology, the relative biological effectiveness is a number that expresses the relative amount of damage that a fixed amount of ionizing radiation of a given type can inflict on biological tissues...

(RBE)
röntgen
Röntgen
The roentgen is a unit of measurement for exposure to ionizing radiation , and is named after the German physicist Wilhelm Röntgen...

(roentgen) (symbol R)
röntgen equivalent man
Röntgen equivalent man
Named after Wilhelm Röntgen , the roentgen equivalent in man or rem is a unit of radiation dose equivalent...

(rem)
sievert
Sievert
The sievert is the International System of Units SI derived unit of dose equivalent radiation. It attempts to quantitatively evaluate the biological effects of ionizing radiation as opposed to just the absorbed dose of radiation energy, which is measured in gray...

(symbol: Sv) (unit of dose equivalent)

See also