Microdosimetry on a Mini-Reactor UTR-KINKI for Educational Uses and Biological Researches

• Published in: JOURNAL OF RADIATION RESEARCH 2009-01, Vol.50 (1), p.83-87
• Main Authors: Endo, Satoru, Tanaka, Kenichi, Fujikawa, Kazuo, Horiguchi, Tetsuo, Itoh, Tetsuo, Onizuka, Yoshihiko, Hoshi, Masaharu, Murataka, Ayanori, Kojima, Yasuaki, Shizuma, Kiyoshi
• Format: Article
• Language: English
• Subjects: Biology - instrumentation; Cell Culture Techniques - instrumentation; Equipment Design; Equipment Failure Analysis; Miniaturization; Nuclear energy; Nuclear Medicine - education; Nuclear Reactors; Oryzias latipes; Radiometry - instrumentation; Radiometry - methods; Research - instrumentation; Tissue Culture Techniques - instrumentation; Tissue Culture Techniques - methods
• ISSN: 0449-3060; 1349-9157; 1349-9157
• DOI: 10.1269/jrr.08072

Microdosimetry study has been carried out at the education and research mini-reactor of Kinki University(UTR-KINKI)using a tissue equivalent gas proportional counter(TEPC). The microdosimetric single event spectra for 0.5, 1, 2, 3 and 5μm site sizes were obtained in the lineal energy range from 1 to 1000 keV/μm. Neutron and gamma-ray fractional doses were estimated from the single event spectra. The neutron dose fraction was varied from 35 to 55% for 0.5 to 5μm site size. The averaged lineal energy, yD, for each site size was likewise estimated and found to be dependent on the site size. The averaged lineal energy for neutron was slightly larger than that of the fission neutrons from 252Cf, and the averaged lineal energy for gamma-ray had similar site-size-dependence of 25 keV gamma-rays and 250kV X-rays. Relative biological effectiveness was found to be 4.1±0.13 for UTR-KINKI using Tilikidis's 2 Gy-response function. The estimated RBE for UTR-KINKI neutrons is quite close to the previous biological experimental value of 4.3±0.6 for micronucleated cells in gill cell of Medaka and 4.6±0.5 for induction of lymphocyte apoptosis in the thymus of ICR mice.