Glossary of terms used on this site
E
| Term | Definition |
|---|---|
| Effective dose |
The quantity obtained by multiplying the equivalent dose to various tissues and organs by a weighting factor appropriate to each and summing the products. Unit sievert, symbol Sv. Frequently abbreviated to dose. |
| Electric field strength |
A measure of the intensity of an electric field. Unit volt per metre, symbol V m-1 |
| Electrical interaction |
A force of repulsion acting between electric charges of like sign and a force of attraction acting between electric charges of unlike sign. |
| Electromagnetic field |
The region in which electromagnetic radiation from a source exerts an influence on another object with or without there being contact between them. |
| Electromagnetic radiation |
Radiation that can be considered as a wave of electric and magnetic energy travelling through a vacuum or a material. Examples are gamma rays, X-rays, ultraviolet radiation, light, infrared radiation and radiofrequency radiation. |
| Electromagnetic spectrum |
All electromagnetic radiations displayed as a continuum in order of increasing frequency or decreasing wavelength. |
| Electromagnetic wave |
See electromagnetic radiation. |
| Electron |
An elementary particle with low mass, 1/1836 that of a proton, and unit negative electric charge. Positively charged electrons, called positrons, also exist. See also beta particle. |
| Electron volt |
Unit of energy employed in radiation physics. Equal to the energy gained by an electron in passing through a potential difference of 1 volt. Symbol eV. 1 eV = 1.6 × 10-19 joule approximately. |
| Element |
A substance with atoms all of the same atomic number. |
| Emergency reference level |
One of a dual set of doses likely to be averted by the introduction of countermeasures to protect the public from ionising radiation after a nuclear or other serious accident. |
| EMF |
Electromagnetic field. Not to be confused with the initials for electromotive force. |
| Enriched uranium |
Uranium in which the content of the isotope uranium-235 has been increased above its natural value of 0.7% by weight. |
| ERL |
See emergency reference level of dose. |
| Erythema |
Reddening of the skin caused by dilation of blood vessels. |