Monte-Carlo Simulation of Conversion Coefficient for Air Kerma From Photon Fluence

The conversion coefficients for air kerma from photon fluence were calculated using Monte-Carlo code EGS5 with photon energy range from 10 keV to 10 MeV. The calculated results of Monte-Carlo simulation show good agreement with the data recommended by ICRP74, ICRU47 reports within ±2.0%, ±3.5%, respectively. The calculated results were fitted to a parametric formula. The values of the formula were in agreement within ±4.0%, ±7.0% compared to the data recommended by ICRP74, ICRU47 reports, respectively.