Tetsuo Horiguchi

Kinki University, Ōsaka, Ōsaka, Japan

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Publications (10)4.07 Total impact

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    ABSTRACT: Systematic Education of the Nuclear Reactor Practices in Combination with a Distance Learning Using Internet Communication Tools
    Journal of Japanese Society for Engineering Education. 01/2011; 59(1).
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    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.
    Journal of Radiation Research 02/2009; 50(1):83-7. · 1.45 Impact Factor
  • Source
    Proc. on 5th International Symposium on Radiation Safety and Detection Technology (ISORD5). 01/2009;
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    ABSTRACT: A dosimetry study of mice irradiation at the Kinki University nuclear reactor (UTR-KINKI) has been carried out. Neutron and gamma-ray doses at the irradiation port in the presence of 0, 1, 2, 4 and 6 mice were measured using the paired chamber method. The results show that neutron dose is reduced with increasing numbers of mice. In the six-mice irradiation condition, neutron dose is about 15% smaller compared to a case where no mice were placed in the irradiation port. To investigate the distortion of the neutron spectrum during mice irradiation at UTR-KINKI, a Monte Carlo calculation using the MCNP4C code has been carried out. The measured variation in dose with respect to the total mouse mass was closely reproduced by the calculation results for neutron and gamma-ray dose. Distortion of the neutron spectrum was observed to occur between 1 keV and 1 MeV.
    Applied Radiation and Isotopes 10/2007; 65(9):1037-40. · 1.18 Impact Factor
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    ABSTRACT: The energy spectrum of fission neutrons in the biological irradiation field of the Kinki University reactor, UTR-KINKI, has been determined by a multi-foil activation analysis coupled with artificial neural network techniques and a Au-foil activation method. The mean neutron energy was estimated to be 1.26 +/- 0.05 MeV from the experimentally determined spectrum. Based on this energy value and other information, the neutron dose rate was estimated to be 19.7 +/- 1.4 cGy/hr. Since this dose rate agrees with that measured by a pair of ionizing chambers (21.4 cGy/hr), we conclude that the mean neutron energy could be estimated with reasonable accuracy in the irradiation field of UTR-KINKI.
    Journal of Radiation Research 01/2003; 43(4):381-6. · 1.45 Impact Factor
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    ABSTRACT: To determine rapidly the core-power ratio in a coupled-core system, a method is proposed on the basis of the control rod drop experiment. A formula of an asymmetrical two-point version was derived to deduce the core-power ratio and subcriticalities of the individual cores. It requires only a familiar measurement technique and tools for the conventional rod drop experiment to apply this formula for the purpose of obtaining these quantities. The present method was applied to the rod drop data measured in coupled-core systems, where the core-power ratio sensitively depended on the rod patterns. The validity of the proposed method was experimentally demonstrated through the comparison between the measured core-power ratios obtained by the present method and that derived from the flux distribution measurement.
    Journal of Nuclear Science and Technology - J NUCL SCI TECHNOL. 01/2000; 37(7):565-571.
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    ABSTRACT: Two-detector Feynman-α measurements were carried out using the UTR-KINKI reactor, a light-water-moderated and graphite-reflected reactor, by detecting high-energy, prompt gamma rays. For comparison, the conventional measurements by detecting neutrons were also performed. These measurements were carried out in the subcriticality range from 0 to $1.8. The gate-time dependence of the variance-and covariance-to-mean ratios measured by gamma-ray detection were nearly identical with those obtained using standard neutron-detection techniques. Consequently, the prompt-neutron decay constants inferred from the gamma-ray correlation data agreed with those from the neutron data. Furthermore, the correlated-to-uncorrelated amplitude ratios obtained by gamma-ray detection significantly depended on the low-energy discriminator level of the single-channel analyzer. The disriminator level was determined as optimum for obtaining a maximum value of the amplitude ratio. The maximum amplitude ratio was much larger than that obtained by neutron detection. The subcriticality dependence of the decay constant obtained by gamma-ray detection was consistent with that obtained by neutron detection and followed the linear relation based on the one-point kinetic model in the vicinity of delayed critical. These experimental results suggest that the gamma-ray correlation technique can be applied to measure reactor kinetic parameters more efficiently.
    Annals of Nuclear Energy - ANN NUCL ENERG. 01/1998; 25(1):13-22.
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    ABSTRACT: The conventional variance-to-mean method (Feynman-α method) seriously suffers the divergency of the variance under such a transient condition as a reactor power drift. Strictly speaking, then, the use of the Feynman-α is restricted to a steady state. To apply the method to more practical uses, it is desirable to overcome this kind of difficulty. For this purpose, we propose an usage of higher-order difference filter technique to reduce the effect of the reactor power drift, and derive several new formulae taking account of the filtering. The capability of the formulae proposed was demonstrated through experiments in the Kyoto University Critical Assembly. The experimental results indicate that the divergency of the variance can be effectively suppressed by the filtering technique, and that the higher-order filter becomes necessary with increasing variation rate in power.
    Annals of Nuclear Energy - ANN NUCL ENERG. 01/1998; 25(9):639-652.
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    ABSTRACT: The Feynman-α (variance-to-mean ratio) measurements were carried out by using fission counters, which contain fissile material of around 2 g, to investigate experimentally the secondary-count effect caused by fission events in the counter. The secondary-count effect was observed when the fission counter was covered with graphite, whereas it was not observed when the bare counter was used and when the counter was surrounded by light-water. Therefore, it was concluded that the secondary-count effect depends not only on fission events in the counter but also on the surrounding material of the counter. A formula to correct the secondary-count effect was derived, and it was applied to obtain the inherent decay constant α. The validity of this formula demonstrated through the comparison with the results obtained by using 3He and BF3 counters which are free from the secondary-count effect.
    Annals of Nuclear Energy - ANN NUCL ENERG. 01/1997; 24(11):907-915.
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    ABSTRACT: In general energy education, it is an exceptional case to provide students with experiments and exercises, especially for the education of nuclear reactor, although such practical approach is useful to ensure student's understanding of lectures on nuclear power plants. All of the reactor facilities for education and research are not easily available from the viewpoint of radiation protection. A tele-education system using the Internet communication tools has been developed for students to learn the control mechanism of nuclear reactor. A trial run was carried out between Setsunan University and Kinki University Atomic Energy Research Institute, and it was confirmed that this system could be applied to practical training of students.