| pitch angle scattering | <physics> Scattering (collisional, or due to wave-particle effects) of particles in velocity space, in which the pitch angle (see entry above) is changed. (09 Oct 1997) |
|---|---|
| Compton scattering | <radiobiology> An attenuation process observed for x and gamma radiation in which an incident photon interacts with an orbital electron of an atom to produce a recoil electron and a scattered photon of energy less than the incident photon. (16 Dec 1997) |
| scattering | <radiobiology> The deflection of one particle as a result of collisions with other particles or with waves. See: Elastic. (09 Oct 1997) |
| 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) |
| Thomson scattering | <radiobiology> Scattering of photons by electrons, in the classical (low photon energy) limit. Laser light passed through a plasma will experience Thomson scattering, the spread of the scattered light in energy provides a very good measurement of the electron temperature of the plasma. (09 Oct 1997) |
| light scattering | Particles suspended in a solution will cause scattering of light and the extent of the scattering is related to the size and shape of the particles (in a somewhat complex relationship). (18 Nov 1997) |
| absorption coefficient | <physics> Measures the degree of wave absorption defined as the fraction of wave energy lost as the wave travels a unit distance. See: absorption. (15 Jan 1998) |
| activity coefficient | <chemistry> The factor by which the value of a concentration of a solute must be multiplied to determine its true thermodynamic activity. (06 May 1997) |
| attenuation coefficient | 1. <radiobiology> Compton: The fractional number of photons removed from a beam of radiation per unit thickness of material through which it is passing as a result of Compton effect interactions. 2. Linear: The fractional number of photons removed from a beam of radiation per unit thickness of material through which it is passing due to all absorption and scattering processes. 3. Pair Production: That fractional decrease in the intensity of a beam of ionising radiation due to pair production in a medium through which it passes. 4. Photoelectric Effect: That fractional decrease in the intensity of a beam of ionising radiation due to photoelectric effect in a medium through which it passes. (16 Dec 1997) |
| biological coefficient | Rarely used term denoting the energy expended by the body at rest. (05 Mar 2000) |
| Bunsen's solubility coefficient | The milliliters of gas STPD dissolved per milliliter of liquid and per atmosphere (760 mm Hg) partial pressure of the gas at any given temperature. (05 Mar 2000) |
| velocity coefficient | The rate of transformation of a unit mass of substance in a chemical reaction. (05 Mar 2000) |
| recombination coefficient | <radiobiology> The rate of recombination of positive ions with electrons (or negative ions) in a gas, per unit volume, divided by the product of the particle densities of the two species (positive ions and electrons/negative ions) involved. (09 Oct 1997) |
| mass attenuation coefficient | <physics> The mass attenuation coefficient, u/p, of a material for uncharged ionising particles is the quotient of DN/N by pdl, where DN/N is the fraction of particles that experience interactions in traversing a distance dl in a material of density p. (16 Dec 1997) |
| mass energy absorption coefficient | <physics> The mass energy absorption coefficient, uen/p of a material for uncharged ionising particles is the product of the mass energy transfer coefficient, utr/p and (1 - g) where g is the fraction of the energy of secondary charged particles that is lost to bremsstrahlung in the material. (16 Dec 1997) |