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Röntgen
 
 
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For other uses of röntgen or roentgen, see Roentgen
Roentgen

R?ntgen or Roentgen may refer to* Wilhelm Conrad R?ntgen, German physicist* Abraham R?ntgen and David R?ntgen, German cabinetmakers* Julius R?ntgen, German-Dutch composer...


The röntgen or roentgen (symbol R) is a unit of measurement for ionizing radiation
Ionizing radiation

Ionizing radiation consists of subatomic particle radiation or electromagnetic radiation that are energetic enough to detach electrons from atoms or molecules, ionize them....
 (such as X-ray
X-ray

X-radiation is a form of electromagnetic radiation. X-rays have a wavelength in the range of 10 to 0.01 nanometers, corresponding to frequency in the range 30 Hertz to 30 Hertz and energies in the range 120 Electron volt to 120 keV....
 and gamma ray
Gamma ray

Gamma rays are a form of electromagnetic radiation produced by atom particle interactions, such as electron-positron annihilation or radioactive decay....
s), and is named after the German
Germany

Germany , officially the Federal Republic of Germany , is a country in Central Europe. It is bordered to the north by the North Sea, Denmark, and the Baltic Sea; to the east by Poland and the Czech Republic; to the south by Austria and Switzerland; and to the west by France, Luxembourg, Belgium, and the Netherlands....
 physicist Wilhelm Röntgen. Adopted in 1928, 1 R is the amount of radiation required to liberate positive and negative charges of one electrostatic unit
Statcoulomb

The statcoulomb or franklin or electrostatic unit of charge is the Units of measurement for electrical charge used in the centimetre gram second system of units electrostatic system of units....
 of charge
Electric charge

Electric charge is a fundamental conserved property of some subatomic particles, which determines their electromagnetic interaction. Electrically charged matter is influenced by, and produces, electromagnetic fields....
 (esu) in 1 cm³ of dry air at standard temperature and pressure (STP).






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For other uses of röntgen or roentgen, see Roentgen
Roentgen

R?ntgen or Roentgen may refer to* Wilhelm Conrad R?ntgen, German physicist* Abraham R?ntgen and David R?ntgen, German cabinetmakers* Julius R?ntgen, German-Dutch composer...


The röntgen or roentgen (symbol R) is a unit of measurement for ionizing radiation
Ionizing radiation

Ionizing radiation consists of subatomic particle radiation or electromagnetic radiation that are energetic enough to detach electrons from atoms or molecules, ionize them....
 (such as X-ray
X-ray

X-radiation is a form of electromagnetic radiation. X-rays have a wavelength in the range of 10 to 0.01 nanometers, corresponding to frequency in the range 30 Hertz to 30 Hertz and energies in the range 120 Electron volt to 120 keV....
 and gamma ray
Gamma ray

Gamma rays are a form of electromagnetic radiation produced by atom particle interactions, such as electron-positron annihilation or radioactive decay....
s), and is named after the German
Germany

Germany , officially the Federal Republic of Germany , is a country in Central Europe. It is bordered to the north by the North Sea, Denmark, and the Baltic Sea; to the east by Poland and the Czech Republic; to the south by Austria and Switzerland; and to the west by France, Luxembourg, Belgium, and the Netherlands....
 physicist Wilhelm Röntgen. Adopted in 1928, 1 R is the amount of radiation required to liberate positive and negative charges of one electrostatic unit
Statcoulomb

The statcoulomb or franklin or electrostatic unit of charge is the Units of measurement for electrical charge used in the centimetre gram second system of units electrostatic system of units....
 of charge
Electric charge

Electric charge is a fundamental conserved property of some subatomic particles, which determines their electromagnetic interaction. Electrically charged matter is influenced by, and produces, electromagnetic fields....
 (esu) in 1 cm³ of dry air at standard temperature and pressure (STP). This corresponds to the generation of approximately 2.08×109 ion
Ion

An ion is an atom or molecule which has lost or gained one or more electrons, giving it a positive or negative electrical charge. According to the Bohr_model this will be from or in the outer shield 'n'....
 pairs.

Until 2006, the röntgen was accepted for use with the SI system but in this case its value is expressed in terms of the SI units charge
Charge (physics)

In physics, a charge may refer to one of many different quantities, such as the electric charge in electromagnetism or the color charge in quantum chromodynamics....
 divided by unit mass (C
Coulomb

The coulomb is the SI unit of electric charge. It is named after Charles-Augustin de Coulomb....
/kg
Kilogram

The kilogram or kilogrammeThe spelling kilogram is used by the International Committee for Weights and Measures and the U.S....
) rather than as in the original definition. Although its use was allowable under the SI system, it is not itself an SI unit and continued use is "strongly discouraged" by the National Institute of Standards and Technology
National Institute of Standards and Technology

The National Institute of Standards and Technology , known between 1901 and 1988 as the National Bureau of Standards , is a measurement standards laboratory which is a non-regulatory agency of the United States Department of Commerce....
.

Explanation


The röntgen was occasionally used to measure exposure to radiation in other forms than X-rays or gamma rays. To adjust for the different impact of different forms of radiation on biological matter, "röntgen equivalent man
Röntgen equivalent man

The r?ntgen equivalent in man or rem is a unit of radiation dose. It is the product of the absorbed dose in r?ntgens and the biological efficiency of the radiation....
" or rem was also in use. Exposure in rems is equal to the exposure in röntgens multiplied by the Q value, a constant describing the type of radiation. The rem is now superseded by the sievert
Sievert

The sievert is the SI derived unit of equivalent dose. It attempts to reflect the biological effects of radiation as opposed to the physical aspects, which are characterised by the absorbed dose, measured in Gray ....
 (see the latter for a list of Q values).

Conversion

In SI
International System of Units

The International System of Units is the modern form of the metric system and is generally a system devised around the convenience of the number ten....
 units, 1 R = 2.58×10−4 C
Coulomb

The coulomb is the SI unit of electric charge. It is named after Charles-Augustin de Coulomb....
/kg
Kilogram

The kilogram or kilogrammeThe spelling kilogram is used by the International Committee for Weights and Measures and the U.S....
 (from 1 esu ˜ 3.33564 C and the standard atmosphere air density of ~1.293 kg/m³).

Dosage

On this scale a dose of about 500 R in 5 hours is lethal for humans.

A typical dose of normal background radiation for a human is 200 mR per year.

See also

  • Wilhelm Conrad Röntgen
    Wilhelm Conrad Röntgen

    Wilhelm Conrad R?ntgen was a Germany physics, who, on 8 November 1895, produced and detected electromagnetic radiation in a wavelength range today known as x-rays or R?ntgen rays, an achievement that earned him the first Nobel Prize in Physics in 1901....
  • rad (unit)
    Rad (unit)

    The rad is a unit of absorbed radiation dose, with symbol rad. The rad was first proposed in 1918 as "that quantity of X rays which when absorbed will cause the destruction of the [malignant mammalian] cells in question..." It was defined in Centimetre gram second system of units in 1953 as the dose causing 100 ergs of energy to be absorb...
     — c.g.s. unit of absorbed dose
  • Gray (unit)
    Gray (unit)

    The gray is the SI unit of absorbed dose due to ionizing radiation ....
     — SI unit of absorbed dose


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