Verification testing of radiation levels of medical accelerator rooms under different irradiation conditions

Objective: To study the X-ray radiation levels of medical accelerator room under different irradiation conditions. Methods: In accordance with the standard GBZ/T 220.2-2009, using the 451B ionization chamber X γ dose rate meter with the 10 MeV accelerator as research object, the research object are divided into two groups, module group and blank group, measuring the radiation dose rate of shield walls and protective doors respectively when the accelerator's rack angle changes in four different gantry angles (0°, 90°, 180°, 270°), analyzing the results. Results: When the angle is 90°, the X-ray dose rate outside the west wall is higher than the other angle. When 270°, the X-ray dose rate outside the east wall is higher than others, and the dose rate outside the protective door is highest in the 270°. The module group's dose rate outside the protective door is 1.5 times higher than blank group. Conclusion: The X-ray radiation dose level surrounding the accelerator room walls and protective door changes while the accelerator's rack angle changes differently. When detecting the doors' radiation level, the module should be set. (authors)