Discussion on the influence factor of induced radioactivity radiation field of high-energy medical linear accelerator and its safeguard measures / 中国医学装备

ABSTRACT

Objective:To discuss the influence factor of induced radioactivity radiation field of high-energy medical linear accelerator and its safeguard measures.Methods: The simulation test was applied to research the radiation level of the induced radioactivity for high-energy medical linear accelerator; and to research the influences of different factors, such as radiation dose, range of exposure and site of exposure and so on, on the changes of radiation field.Results: The research showed that the high-energy X-ray radiation field strength would increase with the increasing of radiation dose, while reduce with the increasing of radiation time; and the obviously reductive trend appeared after radiated 5minutes. Meanwhile, radiation intensity would reduce with the increasing of irradiated area, but the reductive trend was not totally proportional in accordance with the increasing of irradiated area. Additionally, the head part of linear accelerator could produce the most intensity of radiation field on exposure site, and the farther away the head part of linear accelerator, the intensity the lower; and the reductive trend would increase when the distance exceeded 150cm.Conclusion: The induced radioactive radiation field intensity of high-energy medical linear accelerator has some characteristics of change. The effective safeguard measures were to reduce the work time in equipment room, reduce the adjustment time of patient position and choose reasonable exposure site and dose, and all of these measures can reduce the radiation injury.