simulation and comparison of radiology x-ray spectra

monte carlo method is a very accurate method to optimize medical diagnostic radiology spectra and simulation of radiation transportation. using mcnp code, radiology and mammography attenuated x-rayspectraweresimulated.the ipem report number 78 was used as a reference to compare with the geant4 and mcnp simulations because of its popularity and wide availability. the results of geant4 in 40kev showed a good homogeneity with ipem report in terms of intensity, whilst the mcnp code in tube voltage 150kvp showed a very good agreement. whereas thegeant4outputintensityinallcases was less than the ipem report, mcnp code showed higher characteristic peak intensity. the mcnp results were obtained with a less error percentage in comparison with ipem reportexceptatlowenergies. the comparison shows a good agreement between these two codes. mcnp shows a very goodagreement in high tube voltage whereas geant4 showsvery goodagreement in low tube voltage.