Comparison of EGSnrc MC simulation of parallel-plate free air ionization chamber correction factors

With the continuous development of Monte Carlo simulation, it provides greater convenience for the reproducibility of X-ray air kerma. The DOSXYZnrc package in the EGSnrc MC simulation program is used to modify the electron loss, scattering fluorescence and pupil edge penetration of the X-ray free air ionization chamber. Monte Carlo simulation is performed by two different approaches. The comparative analysis reveals the use of phase space files. The deviation between the correction factors obtained by the simulation and the correction factors simulated by the effective energy as the single-energy X-ray is substantially within 0.09%, and the deviations of only 70 kV and 240 kV are respectively 0.15% and 0.3%. The results show that the correction factors obtained by Monte Carlo simulation of effective energy as single-energy X-ray can also be used to correct the air kerma energy. It is more convenient and fast to simulate the correction factors through effective energy.