title: [Analysis of radioactivation induced by high-energy X-rays in medical linear accelerators -estimation of short-lived radioactivated nuclides-].
abstract: In medical linear accelerators, radioactivation is induced on the target and neighborhood parts by photoneutrons accompanying a photo-nuclear reaction and leading to higher acceleration energy. We measured the residual radiation from the radioactivated materials according to the time, and tried to identify radioactivated nuclides and their relative quantities by means of measurement results. It was presumed that the main source of residual radiations was the Target, Flattening filter and Primary collimator in the linac head. Among those materials (copper, tungsten), we calculated decrement curves of residual radiations from radioactivated nuclides generated with photo-nuclear reaction or thermal neutron capture reaction by various ratios, and we investigated the ratio that best fit the measured data. Consequently, it was presumed that (66)Cu generated with thermal neutron capture reaction contributed the most to residual radiation, followed by (62)Cu generated with photo-nuclear reaction contributed. It is important to understand various characteristics of these nuclides and to undertake management of the device.
authors: Fujita Health University, Japan.
authors: Yusuke
authors: Y
authors: Suzuki
authors: Takahiro
authors: T
authors: Aoyama
authors: Hiroki
authors: H
authors: Takahashi
authors: Hideki
authors: H
authors: Kato
authors: Hiroshi
authors: H
authors: Fukuma
authors: Shigeru
authors: S
authors: Isoyama
authors: Makoto
authors: M
authors: Kawano
mesh_terms: D003301:Copper Radioisotopes / Q000032:analysis; D010315:Particle Accelerators; D011868:Radioisotopes / Q000032:analysis*; D011874:Radiometry; D014965:X-Rays
chemical_list: D003301:Copper Radioisotopes; D011868:Radioisotopes