Dose estimation of the neutrons induced by the high energy medical linear accelerator using dual-TLD chips

摘要

This paper discussed the neutron doses induced by the high energy medical linear accelerator (Linac). Thermoluminescent dosimeter (TLD) pairs are usually chosen to distinguish the doses of neutrons from photons in mixed radiation field. In this work, TLD-600 and TLD-700 chips were used to investigate the dose contributions of neutrons induced by 15 MV photon beam of the medical Linac used in radiotherapy. A Rando phantom filled with these dual-TLD chips was irradiated in the 15 MV photon beam to assess the doses contribution of the induced neutrons. Besides, dual-TLD chips were also placed in the treatment room to estimate the spatial dose distribution of neutrons. In the results, dose contributions of neutrons in phantom are less than 0.1% compared with the maximum dose of photons. The dose distribution of neutrons in the treatment room was also revealed.