The Influence Of The Factors For The Linear Accelerator Radiation Protention Research

Study of radiological protection is nuclear physics and nuclear technology is widely used in industry,agriculture,medical care.The research content includes the radiation environment,source properties,induced time and nature of the students,etc.In the field of radiation oncology,radiation protection problems we are interested in,there are two:One is the room outside the working environment of the linear accelerator,Including scattering on the treatment of beam body,The main or patients involving ray projection direction shielding wall effect,Inside the room and fan radiation conditions change,the influence of impact on the room door protection pressure;Second,the accelerator of high-energy X-rays in the gantry in the formation of the nature and rule of induced secondary radiation effect on radiation dose of the radiation protection operation personnel management.These problems is our daily work often have confused problems,and can solve the problem of public literature is limited,so this topic research is of great practical significance.In this paper measurements with ionisation chambers are presented and electronic dosemeters are used for testing at selected positions.The measured time-averaged dose rate ranges from a few microsieverts per hour in the maze to some millisieverts per hour in the vicinity of the accelerator head and up to some sieverts per hour in the blanked primary beam and several hundred sieverts per hour in the direct primary beam.Various studies can be found in the literature which are dealing with the dose outside but close to the target volume,i.e.inside the patient or phantom,e.g.The leakage dose of various accelerator have also be extensively studied.These studies are focused on doses in the direct vicinity of the accelerator head or the iso-centre.Only a few studies investigate the dose rates during therapy in the greater distance from the accelerator,i.e.in the radiation protection maze.Since there are,up to the author’s knowledge,no results for an Elekta Precise,especially in the greater distance from the accelerator head,the aim of this study is the measurement of the dose and dose rate distribution in the greater vicinity of the accelerator.The measurements should be performed using traceable calibrated ionisation chambers and measurement equipment.