Measurement and analysis of induced radioactivity in medical electronic linear accelerator / 中国辐射卫生

ABSTRACT

Objective By measuring the induced radioactivity of the medical electron linear accelerator, and analyzing the measuring results and the measuring process, the cooling law of the induced radioactivity was studied, to provide basic data for evaluating additional doses to patients, medical staff and the public. Methods Five Medical Electron Linear accelerators were used to measure the induced radioactivity by using automes-6150AD6/H+6150AD-b/H x-γ radiation peripheral dose equivalent rate meter for environmental monitoring. Results The level of induced radioactivity of 5 medical electron linear accelerators is related to the factors such as measuring position and time 10 second after the end of beam output, the maximum dose equivalent rate is 5.55 μSv/h around 5 cm on the surface of the head housing of the accelerator, and the maximum ambient dose equivalent rate at 1 m from the fixed point of the housing is 4.07 μSv/h, 5 minutes after the end of output, the maximum dose equivalent rate is 2.11 μSv/h around the 5 cm surface and 1.77 μSv/h around the 1 m fixed point. Conclusion The measured radioactivity induced by the medical electron linear accelerator gradually cools over time, the measurement valuesare maintained in a relatively fixed range, and the fluctuation range of the values is narrow.