Yasubuchi S, Hoshi M, Itoh T, Hisanaga S, Niwa T, Miki R, Kondo S
Nagase Landauer Ltd., Tokyo, Japan.
Radioisotopes. 1989 Sep;38(9):359-65. doi: 10.3769/radioisotopes.38.9_359.
A nuclear reactor at Kinki University is operated at the maximum of 1W. It produces fission neutrons as much as gamma-rays. To facilitate its use for neutron radiobiology, fast neutrons inside the reactor were measured with nuclear-track detectors TS 16 N and a pair of ion chambers. The angular dependence of TS 16 N response, an anisotropy of fast neutron fluxes in the reactor and misuse of the kerma factor assumed for radiation protection business are the major causes of discrepancy is measured doses by the two methods. Correction factors for the three causes are proposed. After correction, neutron doses estimated with TS 16 N and chambers agree within 5%. The dose-rate at the reactor's center is about 20 tissue-cGy/h. This is the first in situ dosimetry of fast neutrons in a reactor with track detectors attached to biologic samples. Our routine usage has demonstrated that, if used with caution, TS 16 N elements are handy, reliable monitors for fast neutron dosimetry as they are insensitive to contaminated gamma-rays and small enough to be attached to biologic samples.
近畿大学的一座核反应堆以最大功率1瓦运行。它产生的裂变中子与伽马射线一样多。为便于将其用于中子放射生物学研究，利用核径迹探测器TS 16 N和一对电离室对反应堆内部的快中子进行了测量。TS 16 N响应的角度依赖性、反应堆内快中子通量的各向异性以及辐射防护业务中假定的比释动能因子的误用是两种方法测量剂量存在差异的主要原因。针对这三个原因提出了校正因子。校正后，用TS 16 N和电离室估算的中子剂量在5%以内相符。反应堆中心的剂量率约为20组织厘戈瑞/小时。这是首次在反应堆中对附着在生物样品上的快中子进行原位剂量测定。我们的日常使用表明，如果谨慎使用，TS 16 N元件是方便、可靠的快中子剂量监测器，因为它们对受污染的伽马射线不敏感，且体积小到足以附着在生物样品上。
