Virtual Booth

The major aim of the study is to use Monte Carlo (MC) simulation method to design and optimize the biological shielding of a radiotherapy treatment vault that is planned to be used in a medical linear accelerator (LINAC). The Monte Carlo transport code, Geant4 is used to create an all-inclusive simulation environment in the study. This framework includes making specific input files containing the geometry of the vault and the source of radiation, but pays particular attention to physics models that specify photon and electron transport. Also, since high-energy beams (≥10 MV) are to be analyzed, evaluation of photoneutron production is explicitly a part of the scope of the simulation, which is essential in ensuring shielding integrity. Geometrically, we have a narrow scope in the form of a typical treatment vault of a maze design. A simplified, but otherwise radiologically realistic, model of the LINAC head which consists of target, primary collimator, and flattening filter is included in the computational model to generate realistic energy spectra. The structural modeling is extended to primary barriers, which block the direct beam and secondary barriers which absorb scatter and leakage radiation. The simulation also uses a water phantom to consider the issue of patient scatter to ensure the area of distribution of the radiations is realistic in the vault.