Radiation weighting factors

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The probability of stochastic radiation effects depends not only on the absorbed dose, but also on the type and energy of the radiation causing the dose. This is considered by weighting the absorbed dose with a factor related to the radiation quality. For photon and electron radiation, the radiation weighting factor has the value 1 independently of the energy of the radiation and for alpha radiation the value 20. For neutron radiation, the value is energy-dependent and amounts to 5 to 20.

Radiation weighting factor W_R in accordance with Euratom basic standards

The numerical values indicated above are valid legal EU-regulations for the calculation of the equivalent dose in an organ or tissue. In 2007 ICRP published a new set of radiation weighting factors (ICRP Publ. 103: The 2007 Recommendations of the International Commission on Radiological Protection) given below. These data are adopted in the proposal of the new EU Basic Safety Standards (European Commission, Proposal for a Council Directive, COM(2011) 593 final, 2011-09-29) for approval by the Council of the European Union.

Radiation weighting factors (ICRP 2007)

Continuous function in neutron energy, E_n (MeV),
for the calculation of radiation weighting factors for neutrons

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