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Fundamental to radiation protection is the avoidance or reduction of dose using the simple protective measures of time, distance and shielding. The duration of exposure should be limited to that necessary, the distance from the source of radiation should be maximised, and the source or the target shielded wherever possible.
For a point source, the exposure rate will be linearly proportional to the source's radioactivity and inversely proportional to the square of the distance, [32] F = Γ×α / r 2 where F is the exposure rate, r is the distance, α is the source activity, and Γ is the exposure rate constant, which is dependent on the particular radionuclide used ...
Because such radiation expands as it passes through space, and as its energy is conserved (in vacuum), the intensity of all types of radiation from a point source follows an inverse-square law in relation to the distance from its source. Like any ideal law, the inverse-square law approximates a measured radiation intensity to the extent that ...
Radiation dosimetry in the fields of health physics and radiation protection is the measurement, calculation and assessment of the ionizing radiation dose absorbed by an object, usually the human body. This applies both internally, due to ingested or inhaled radioactive substances, or externally due to irradiation by sources of radiation.
Exposing skin to infrared radiation near visible light (IR-A) leads to increased production of free radicals. [41] Short-term exposure can be beneficial (activating protective responses), while prolonged exposure can lead to photoaging. [42] Another important factor is the distance between the worker and the source of radiation.
The distance from the source of radiation; The absorption or scattering of particles by the medium (such as air) between the source and the surface of the detector; The detector efficiency in counting all radiation photons and particles that reach the surface of the detector; The accompanying diagram shows this graphically.
A radioactive source is a known quantity of a radionuclide which emits ionizing radiation, typically one or more of the radiation types gamma rays, alpha particles, beta particles, and neutron radiation. Sources can be used for irradiation, where the radiation performs a significant ionising function on a target material, or as a radiation ...
A year after Röntgen's discovery of X-rays in 1895, the American engineer Wolfram Fuchs gave what was probably the first radiation protection advice, but many early users of X-rays were initially unaware of the hazards and protection was rudimentary or non-existent. [11] The dangers of radioactivity and radiation were not immediately recognized.