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The concept of the rem first appeared in literature in 1945 [17] and was given its first definition in 1947. [18] The definition was refined in 1950 as "that dose of any ionizing radiation which produces a relevant biological effect equal to that produced by one roentgen of high-voltage x-radiation."
That model calculates an effective radiation dose, measured in units of rem, which is more representative of the stochastic risk than the absorbed dose in rad. In most power plant scenarios, where the radiation environment is dominated by X-or gamma rays applied uniformly to the whole body, 1 rad of absorbed dose gives 1 rem of effective dose. [5]
The roentgen or röntgen (/ ˈ r ɛ n t ɡ ə n,-dʒ ə n, ˈ r ʌ n t-/; [2] symbol R) is a legacy unit of measurement for the exposure of X-rays and gamma rays, and is defined as the electric charge freed by such radiation in a specified volume of air divided by the mass of that air (statcoulomb per kilogram).
Recognized effects of higher acute radiation doses are described in more detail in the article on radiation poisoning.Although the International System of Units (SI) defines the sievert (Sv) as the unit of radiation dose equivalent, chronic radiation levels and standards are still often given in units of millirems (mrem), where 1 mrem equals 1/1,000 of a rem and 1 rem equals 0.01 Sv.
The rad (rad) is a unit of absorbed dose equal to 10 mGy. The roentgen equivalent man (rem) is a unit of equivalent dose equal to 10 mSv. The rutherford (Rd) is a unit of radioactivity defined as one million decays per second (1 MBq).
the rad (radiation absorbed dose), now replaced by the gray; and; the rem (Röntgen equivalent man), now replaced by the sievert. [25] The rad and rem are essentially equivalent for almost all nuclear medicine procedures, and only alpha radiation will produce a higher Rem or Sv value, due to its much higher Relative Biological Effectiveness ...
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.
These measurements, ALI and DAC, are calculated values based on the dose an average employee working 2,000 hours a year may be exposed to. The current legal limit exposure in the United States is 1 ALI, or 5 rems. A rem, or roentgen equivalent man, is a measurement of absorption of radiation on parts of the body over an extended period of time ...