Roentgen unit

Is the roentgen unit used in the measurement of alpha particle radiation Why or why not ... 

Ra.dia.tlon Units. Units in use for activity of a radionucHde, ie, the curie, the roentgen (exposure to x and gamma rays), the rad (absorbed dose), and the rem (dose equivalent), should eventually be replaced by the becquerel (Bq), coulomb per kilogram (C/kg), gray (Gy), and the sievert (Sv), respectively. 

The roentgen is the international unit of quantity for both x-rays and y-rays. It is the quantity of this radiation which will produce, as a, result of ionization, one electrostatic unit of charge, of either sign, in one cubic centimeter of dry air (as measured at 0° C and standard atmospheric pressure). 

The former (non-SI) unit of dose equivalent was the roentgen equivalent man (rem), which was defined in the same way as the sievert but with the absorbed dose in rad thus, 1 rem = 10 2 Sv. 

Rep—Roentgen equivalent, physical A former unit of ionizing radiation equivalent to the dosage of 93 ergs absorbed per gram of tissue (93 erg/gm=0.93 rad). 

Roentgen (R)—A unit of exposure (in air) to ionizing radiation. It is the amount of x or gamma rays required to produce ions carrying 1 electrostatic unit of electrical charge in 1 cubic centimeter of dry air under standard conditions. Named after William Roentgen, a German scientist who discovered x rays in 1895. 

The ICRU (1980), ICRP (1984), and NCRP (1985) now recommend that the rad, roentgen, curie, and rem be replaced by the SI units gray (Gy), Coulomb per kilogram (C/kg), Becquerel (Bq), and sievert (Sv), respectively. The relationship between the customary units and the international system of units (SI) for radiological quantities is shown in Table D-5. 

Radiation dose Level of exposure to radiation, expressed in units called Roentgen equivalents in man (rem) a dose of approximately 400 rem is fatal in 50% of cases when medical treatment is not available. No health effects are typically observed at doses below 10 rem. 

Rem (Roentgen equivalent in man) Special unit of any quantity expressed as a dose equivalent the dose equivalent in rems is equal to the absorbed dose in rads multiplied by the quality factor (1 rem = 0.01 Sv). 

Symbolized by R, the roentgen is the international unit of exposure dose. It is equal to that quantity of radiation that will produce a charge of 2.58 x 10 coulombs on all the ions of one sign, when all the electrons released in a volume of air (at STP) of a mass of one kilogram are completely stopped. 

Rem (acronym for roentgen-equivalent man) The unit of dose of ionizing radiation that produces the same biological effect as a unit of absorbed dose of ordinary x-rays. 

Roentgen (R) The unit of radiation exposure in the air units for quantities of X-ray or gamma radiation measured by detection and survey meters. Named after Wilhelm Roentgen, German scientist who discovered X-rays in 1895. 

Information concerning Sedan was obtained from the report by Lane (2). He reports equivalent fissions per gram for material from fallout trays between 5800 and 19,200 ft. from ground zero for a series of nuclides. The determinations show random scatter and do not indicate a trend with distance. Therefore, the values for different trays were averaged. A report by Nordyke and Williamson (3) provided the experimental determination of fallout-mass area density divided by gamma field readings in units of (kg./sq. meter)/(roentgens/hr.) over the same fallout area. These two sources provided the necessary input to calculate the fractionation indices for Sedan. 

As a rough check on the magnitude of the indices in Table I, a theoretical estimate of the fractionation index for unfractionated fission products can be calculated as follows. The index has the units kiloton-hr./ft.2 roentgens if we use the most probable value of 2500 roentgens /hr. for 1 kiloton/sq. mile over Nevada Test Site terrain for unfractionated fission products, we obtain (since 1 square mile = 2.78 X 107 ft.2)... 

ROENTGEN. A unit of radiation, that quantity of X-rays or gamma rays which will produce, as a consequence of ionization, 1 electrostatic unit of... 

REM (rem). A unit of dose equivalent in the field of radiation dosimetry. One rem equals the amount of ionizing radiation of any type which produces the same damage to humans as 1 roentgen of approximately 200 kilovolts x-radiation. (The unit is abbreviation of Roentgen Equivalent Man.)... 

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