title: Microdosimetry on a mini-reactor UTR-KINKI for educational uses and biological researches.
abstract: 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 5 microm site sizes were obtained in the lineal energy range from 1 to 1000 keV/microm. 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 5 microm site size. The averaged lineal energy, y(D), 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 (252)Cf, and the averaged lineal energy for gamma-ray had similar site-size-dependence of 25 keV gamma-rays and 250 kV 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.
authors.affiliation: Quantum Energy Applications, Graduated School of Engineering, Hiroshima University, 1-4-1, Kagamiyama, Higashi-Hiroshima 739-8527, Japan. endos@hiroshima-u.ac.jp
authors.forename: Satoru
authors.initials: S
authors.lastname: Endo
authors.forename: Kenichi
authors.initials: K
authors.lastname: Tanaka
authors.forename: Kazuo
authors.initials: K
authors.lastname: Fujikawa
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Horiguchi
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Itoh
authors.forename: Yoshihiko
authors.initials: Y
authors.lastname: Onizuka
authors.forename: Masaharu
authors.initials: M
authors.lastname: Hoshi
authors.forename: Ayanori
authors.initials: A
authors.lastname: Murataka
authors.forename: Yasuaki
authors.initials: Y
authors.lastname: Kojima
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Shizuma
mesh_terms: D001695:Biology / Q000295:instrumentation*; D018929:Cell Culture Techniques / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D008904:Miniaturization; D009683:Nuclear Medicine / Q000193:education*; D009688:Nuclear Reactors; D011874:Radiometry / Q000295:instrumentation* / Q000379:methods; D012106:Research / Q000295:instrumentation*; D046509:Tissue Culture Techniques / Q000295:instrumentation* / Q000379:methods