Monte Carlo Simulation Of Neutron Contamination Inside High Energy LINAC Radiotherapy Treatment Rooms

Radiation therapy is an important application of nuclear technology in themedical field. The physics of radiation therapy has become a pivotalinterdiscipline subject in clinical oncology treatment system. Radiation therapytechnology has developed rapidly in recent years. As the development of radiationtechnology, Linac which can provide X-ray with the energy of10MV and abovehas been widely used in clinical trials. However, as neutrons generated by thereaction between high energy phonon beam and the high-Z material would beoverdosed, thus a more accurate detection of the neutrons produced by photons isrequired. In the recent decades, Monte Carlo method has been introduced tonuclear physics research. This application can make evaluation of Medicalradiation equipment’s influence on environment, meanwhile amending the plan ofmedical therapy.My work was using MC method to monitor photons and neutrons that medicallinear accelerator generated in the environment of therapy room and maze regionrespectively, and calculating the dose of neutrons at different interest points fromdifferent detection angles. This model was based on the15MV X-ray mode Clinac2100CD linear accelerator (made by Varian). The work also used MCNPX tomodel the specific calculation. Frist, I confirmed the feasibility of the model bymonitoring the photon data. Second, I targeted the source of neutrons bymonitoring the neutron flux at the cross section of front radiation. Thereafter, fixedat the angle of30degree, I obtained the dose of peripheral equivalent (H*(10)) at5interest points maze region as well as therapy room, respectively. There are two aims of this work, with the first one of providing referential data for extra neutrondose subjected on patients and the second one of offering theoretical basis for thefollowing high energy accelerator induced radiation therapy research.