title: An MCNP-based model of a medical linear accelerator x-ray photon beam.
abstract: The major components in the x-ray photon beam path of the treatment head of the VARIAN Clinac 2300 EX medical linear accelerator were modeled and simulated using the Monte Carlo N-Particle radiation transport computer code (MCNP). Simulated components include x-ray target, primary conical collimator, x-ray beam flattening filter and secondary collimators. X-ray photon energy spectra and angular distributions were calculated using the model. The x-ray beam emerging from the secondary collimators were scored by considering the total x-ray spectra from the target as the source of x-rays at the target position. The depth dose distribution and dose profiles at different depths and field sizes have been calculated at a nominal operating potential of 6 MV and found to be within acceptable limits. It is concluded that accurate specification of the component dimensions, composition and nominal accelerating potential gives a good assessment of the x-ray energy spectra.
authors: Department of Physics, Faculty of Applied Sciences, Umm Al-Qura University, Makkah, Saudi Arabia, P.O. Box 10130. msms1404@hotmail.com
authors: F A
authors: FA
authors: Ajaj
authors: N M
authors: NM
authors: Ghassal
mesh_terms: D003198:Computer Simulation; D008954:Models, Biological; D009010:Monte Carlo Method; D010315:Particle Accelerators; D011522:Protons; D011829:Radiation Dosage; D011874:Radiometry / Q000379:methods*; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods*; D011882:Radiotherapy, High-Energy / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014965:X-Rays
chemical_list: D011522:Protons