The air kerma rate constants of 39 nuclides is commonly calculated

Abstract: The radionuclide air kerma rate constant Γa.Γa is a very important data in dose evaluation and shielding calculation, which requires the conversion coefficient of flux to air Kerma Ka/Φ and the information of nuclide decay photon. In 2020, the International Commission on Radiation and Measurements (ICRU) released Report 95 (Operational Quantities for External Radiation Exposure), which recommended a new Ka/Φ.[Purpose]: In order to verify the change in nuclide values after the basic data was updated.[Methods]: Based on the theory and Monte Carlo method, the air specific kinetic energy rate constants of 39 kinds of nuclides commonly used in medicine, industry and agriculture were calculated, and different interpolation methods and threshold selection were compared and analyzed.[Results and conclusions]: The cubic splines, logarithmic-logarithmic Lagrangian interpolation, and linear-logarithmic Lagrangian interpolation interpolation methods have little influence on the calculation of Γa. The calculation of Γa threshold selection pairs is very important, and the calculation of some nuclides with different thresholds is quite different, and the recommended nuclear medicine dose estimation is recommended to use a threshold of 10 keV, and the threshold of other cases is 20 keV. The difference between theoretical calculation and MCNP simulation calculation is small, and both can be used for constants calculation