GET 8-2019 STATE PRIMARY STANDARD OF UNITS OF AIR KERMA, AIR KERMA RATE, EXPOSURE, EXPOSURE RATE, AND ENERGY FLUX OF X-RADIATION AND GAMMA RADIATION

摘要

Results of studies designed to improve GET 8-2011, the State Primary Standard of the units of air kerma, air kerma rate, exposure, exposure rate, and energy flux of x-radiation and gamma radiation, are described. The studies are performed in 2019 to implement the recommendations of Report No. 90, Key Data for Dosimetry of Ionizing Radiation: Standards and Applications, International Commission on Radiation Units and Measurements. The following changes are introduced into the equation for reproduction of the units of quantities in GET 8-2019: in the field of x-radiation, new correction factors for free-air ionization chambers are introduced and the value of the relative standard uncertainty of the mean ionization energy is changed; in the field of gamma radiation, the values of the product of the mean ionization energy and ratio of the mass stopping powers of graphite to air in measurements with cavity ionization chambers are changed. More accurate values of the units of quantities reproduced by GET 8-2019 are obtained.