| recombination radiation | <physics> Radiation produced when a free electron in a plasma is captured by an ion. (09 Oct 1997) |
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| Cerenkov radiation | Light given off by a transparent medium when a high energy particle speeds through it at a velocity greater than that of light in that medium. (05 Mar 2000) |
| characteristic radiation | Monochromatic radiation that is produced when an electron is ejected from an atom and another takes its place by jumping from another shell; the energy of the photon is the difference between that of the two shell positions. Synonym: characteristic emission. (05 Mar 2000) |
| Gratiolet's radiation | The massive, fanlike fibre system passing from the lateral geniculate body of the thalamus to the visual cortex (striate or calcarine cortex, area 17 of Brodmann); the fibres follow the retrolenticular and sublenticular limbs of the internal capsule into the corona radiata but they curve back along the lateral wall of the temporal and occipital horns of the lateral ventricle to the striate cortex on the medial surface and pole of the occipital lobe. Synonym: radiatio optica, geniculocalcarine radiation, geniculocalcarine tract, Gratiolet's fibres, Gratiolet's radiation, occipitothalamic radiation, Wernicke's radiation. (05 Mar 2000) |
| microwave radiation | Electromagnetic radiation with wavelengths between 3 millimetres and 300 millimetres. Used in radar, these waves have frequencies between 1-100 gigahertz. Microwaves have also been harnessed for cooking in microwave ovens. (09 Oct 1997) |
| photodynamic radiation therapy | <oncology, technique> A light sensitive drug is given through a vein and concentrates in the tumour. Then, during a surgical procedure, a special light activates the drug. The activated drug kills tumour cells. (31 Dec 1997) |
| coherent radiation | <physics> Any form of radiation in which the phase relationship between sections of the wave at different locations is not random (or incoherent!). Typical example is a laser beam, in which the phase is more or less uniform across the beam and changes along the beam in accordance with the wavelength. Radiation in which the photons tend to correlate with one another, rather than being randomly distributed. (09 Oct 1997) |
| Wernicke's radiation | The massive, fanlike fibre system passing from the lateral geniculate body of the thalamus to the visual cortex (striate or calcarine cortex, area 17 of Brodmann); the fibres follow the retrolenticular and sublenticular limbs of the internal capsule into the corona radiata but they curve back along the lateral wall of the temporal and occipital horns of the lateral ventricle to the striate cortex on the medial surface and pole of the occipital lobe. Synonym: radiatio optica, geniculocalcarine radiation, geniculocalcarine tract, Gratiolet's fibres, Gratiolet's radiation, occipitothalamic radiation, Wernicke's radiation. (05 Mar 2000) |
| corpuscular radiation | Radiation consisting of streams of subatomic particles such as protons, electrons, neutrons, etc. (05 Mar 2000) |
| cosmic radiation | <radiobiology> High-energy radiation or particles from extraterrestrial space that strike the earth, its atmosphere, or spacecraft and may create secondary radiation as a result of collisions with the atmosphere or spacecraft. (12 Dec 1998) |
| primary radiation | An incident X-ray beam. (05 Mar 2000) |
| scattered radiation | Secondary radiation emitted from the interaction of X-rays with matter; generally lower in energy, with a directional distribution which depends on the energy of the incident radiation. Synonym: secondary radiation. (05 Mar 2000) |
| scattering, radiation | The process in which energy is removed from a beam of light or other electromagnetic radiation and emitted without appreciable change in wavelength. May be considered as the change in direction of a particle or photon owing to a collision with another particle or system. (12 Dec 1998) |
| heterogeneous radiation | Radiation consisting of different frequencies, various energies, or a variety of particles. (05 Mar 2000) |
| x-radiation | Radiant energy from an X-ray tube. See: X-ray. (05 Mar 2000) |