Code of practice for the protection of persons exposed to ionizing radiations / [prepared by the Standing Advisory Committee].

  • Great Britain. Radioactive Substances Advisory Committee.
Date:
1957
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Licence: Public Domain Mark

Credit: Code of practice for the protection of persons exposed to ionizing radiations / [prepared by the Standing Advisory Committee]. Source: Wellcome Collection.

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    Nuclide: a particular variety of atom having a nucleus characterized by a specific atomic number and specific mass number. Photon: corpuscular manifestation of a quantum of radiant energy. Proportional counter: a form of ionization chamber equipped with suitable electrodes between which an electric field is applied which is high enough to produce ionization by collision and so adjusted that the total ionization per count is substantially proportional to the ionization produced in the gas by particles or quanta of radiation entering the counter. Protection: provisions designed to reduce exposure of personnel to ionizing radiation. Protective barrier: material used for absorbing ionizing radiation for protection purposes. Pulsating potential (or voltage): a unidirectional potential (or voltage) which undergoes periodic variations in magnitude at a frequency related to that of the mains supply. Qualified expert: a person having the knowledge and training needed to measure ionizing radiations and to advise regarding radiation hazard. The qualifica- tion should be of the type specified by a National Committee—in the United Kingdom, the Radioactive Substances Advisory Committee. | Quantity of radiation: time integral of intensity. It is the total energy which has passed through unit area perpendicular to the beam and is expressed in ergs per square centimetre or watt-seconds per square centimetre. Quantum: the smallest quantity of energy in the form of a bundle or packet of waves of electromagnetic radiation which can be associated with a given phenomenon. (Electromagnetic radiation sometimes appears to consist of waves and at other times of particles. Such particles may be regarded as bundles of waves.) Quantum energy: energy contained in a quantum of radiation and proportional to the frequency of the radiation waves. (The energy E of a quantum of radiation of frequency v is hy where h is Planck’s constant.) Rad: unit of absorbed dose. It is 100 ergs per gramme. Millirad (mrad): 1/1,000 rad. Radiation: (1) Broad-beam: condition in which there is no collimation of a beam of X- or -rays which penetrate material and in which there is an admix- ture with the emergent beam of scattered electromagnetic radiation, produced during the Compton process of absorption of the radi- ation in the material penetrated. (See Narrow-beam.)