Monte Carlo simulation of X-ray spectra produced by Linac

Abstract

This study was conducted to determine the intensity distribution of X-ray energy spectrum of that produced by Linear Accelerator (Linac) with tungsten target (W). The x-ray spectra on the space behind of target is calculated through the simulation method using Monte Carlo N-Particle eXtended version software (MCNPX). Linac is simulated with acceleration voltage 6 MV up to 15 MV using tungsten metal target (W). Based on the simulation of electron source accelerated, X-rays generated mostly (40-75) % are X-rays with energy of 1 MeV to 2 MeV, whereas the intensity of X-rays with energies fit the energies of the shooter’s electrons is very small (0.03 -0.340)%. It was indicated that the energy spectra dominated in the 1 MeV to 2 MeV than maximum energy in the x-ray spectrum range along the energy variation of Linac radiotherapy simulation. In addition, also found electrons about 2.24% to 5.67% compared to the intensity of X-rays, so as to increase the equivalent dose in the patient’s tissue later. This information can be used for the manufacture of low energy range filter design that dominate the spectrum and consideration of radiation protection efforts.