KINDAI UNIVERSITY


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WAKABAYASHI Genichiro

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FacultyAtomic Energy Research Institute
PositionProfessor
Degree
Commentator Guidehttps://www.kindai.ac.jp/meikan/267-wakabayashi-genichirou.html
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Last Updated :2020/09/30

Education and Career

Education

  •   1990 04  - 1994 03 , Kyushu University, School of Engineering
  •   1994 04  - 1996 03 , Kyushu University
  •   1996 04  - 1998 09 , Kyushu University

Academic & Professional Experience

  •   2020 04 ,  - 現在, professor, Atomic Energy Research Institute, Kindai University
  •   2014 04 ,  - 2020 03 , Atomic Energy Research Institute, Kindai University
  •   2011 04 ,  - 2014 03 , Lecturer, Atomic Energy Research Institute, Kinki University
  •   2007 04 ,  - 2011 03 , Faculty of Engineering, Department of Applied Quantum Physics and Nuclear Engineering, Kyushu University
  •   1998 10 ,  - 2007 03 , Faculty of Engineering, Department of Applied Quantum Physics and Nuclear Engineering, Kyushu University

Research Activities

Research Areas

  • Energy, Nuclear engineering
  • Energy, Quantum beam science

Published Papers

  • An application of CCD read-out technique to neutron distribution measurement using the self-activation method with a CsI scintillator plate, Nohtomi Akihiro, Kurihara Ryosuke, Kinoshita Hiroyuki, Honda Soichiro, Tokunaga Masaaki, Uno Heita, Shinsho Kiyomitsu, Wakabayashi Genichiro, Koba Yusuke, Fukunaga Junichi, Umezu Yoshiyuki, Nakamura Yasuhiko, Ohaga Saiji, NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT, NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT, 832, 21 - 23, Oct. 01 2016 , Refereed
  • Survey of Radioactive Contamination in Fukushima Naka-dori Region, Fukushima, Japan, Sin-ya Hohara, Masayo Inagaki, Hirokuni Yamanishi, Genichiro Wakabayashi, Wataru Sugiyama, Tetsuo Itoh, The 12th International Conference on Radiation Shielding (ICRS-12) and the 17th Topical Meeting of the Radiation Protection and Shielding Division of ANS (RPSD-2012), Progress in Nuclear Science and Technology, The 12th International Conference on Radiation Shielding (ICRS-12) and the 17th Topical Meeting of the Radiation Protection and Shielding Division of ANS (RPSD-2012), Progress in Nuclear Science and Technology, 4, 39 - 42, Apr. 2014 , Refereed
  • A Method of Neutron-energy Evaluation Based on the Position Distribution of Recoil Protons, Daiki Nakanishi, Akihiro Nohtomi, Ryoji Tanaka, Genichiro Wakabayashi, The 12th International Conference on Radiation Shielding (ICRS-12) and the 17th Topical Meeting of the Radiation Protection and Shielding Division of ANS (RPSD-2012), Progress in Nuclear Science and Technology, The 12th International Conference on Radiation Shielding (ICRS-12) and the 17th Topical Meeting of the Radiation Protection and Shielding Division of ANS (RPSD-2012), Progress in Nuclear Science and Technology, 4, 653 - 656, Apr. 2014 , Refereed
  • High sensitive neutron-detection by an NaI(Tl) scintillator with a novel self-activation method, Ionizing Radiation, Ionizing Radiation, 40(1), 55 - 58, Mar. 2014 , Refereed
  • An Observation of the Pulse-shape property of a Polyethylene-lined Proportional Counter for Fast Neutrons and Gamma-rays, A. Nohtomi, F. Toyofuku, A. Sato, S. Nagamine, G. Wakabayashi, Proceedings of the 27th Workshop on Radiation Detectors and Their Uses, Proceedings of the 27th Workshop on Radiation Detectors and Their Uses, 51 - 62, Jan. 2014 , Refereed
  • Support Activities for Radiation Protection and Measurements in Kawamata-machi, Fukushima Prefecture, Japan, WAKABAYASHI GEN'ICHIRO, YAMANISHI HIROKUNI, HOHARA SHIN'YA, INAGAKI MASAYO, ITO TETSUO, HORIGUCHI TETSUO, KOJIMA KIYOSHI, SUGIURA NOBUYUKI, FURUKAWA MICHIO, 放射線, 放射線, 38(4), 155 - 158, Jul. 2013
  • Survey of Radioactive Contamination in Urban distracts of Naka-Dori Area due to Fukushima-Daiichi Nucler Plant Accident, HOHARA SHIN'YA, INAGAKI MASAYO, YAMANISHI HIROKUNI, WAKABAYASHI GEN'ICHIRO, SUGIYAMA WATARU, ITO TETSUO, 近畿大学原子力研究所年報, 近畿大学原子力研究所年報, 48, 11 - 21, Mar. 25 2012
  • 福島県川俣町における環境放射線調査, 伊藤哲夫, 古川道郎, 杉浦紳之, 山西弘城, 堀口哲男, 芳原新也, 若林源一郎, 稲垣昌代, 小島清, 村田祥之, 野間宏, KURRI KR, KURRI KR, (170), 1 - 4, Mar. 2012
  • Corrigendum: Survey of Living Environmental Land Contaminated with Radioactive Materials due to Fukushima Daiichi Nuclear Plant Accident, HOHARA Sin-ya, INAGAKI Masayo, KOJIMA Kiyoshi, YAMANISHI Hirokuni, WAKABAYASHI Genichiro, SUGIYAMA Wataru, ITOH Tetsuo, Transactions of the Atomic Energy Society of Japan, Transactions of the Atomic Energy Society of Japan, 11(4), 340 - 340, 2012
  • Environmental radiation survey in Kawamata-machi, Fukushima-ken: Measurement of radiocesium in soil and plants, H. Yamanishi, M. Inagaki, G. Wakabayashi, S. Hohara, T. Itoh, M. Furukawa, Proceedings of the International Symposium on Environmental monitoring and dose estimation of residents after accident of TEPCO’s Fukushima Daiichi Nuclear Power Station, Proceedings of the International Symposium on Environmental monitoring and dose estimation of residents after accident of TEPCO’s Fukushima Daiichi Nuclear Power Station, 49 - 52, 2012 , Refereed
  • Survey of living environmental land contaminated with radioactive materials due to Fukushima Daiichi nuclear plant accident, Sin-Ya Hohara, Masayo Inagaki, Kiyoshi Kojima, Hirokuni Yamanishi, Genichiro Wakabayashi, Wataru Sugiyama, Tetsuo Itoh, Transactions of the Atomic Energy Society of Japan, Transactions of the Atomic Energy Society of Japan, 10(3), 145 - 148, Sep. 2011
    Summary:Radioactive materials were released to the general environment due to the accident at the Fukushima Daiichi nuclear power station. The released radioactive materials fell and contaminated the land mainly in the Tohoku and Kanto areas of Japan. We surveyed the air dose rate in relation to the pave condition of the land, and investigated the contamination level in some nonpaved areas at the center of Fukushima City, Koriyama City, and Nasushiobara City. From the survey results, the dose rates of the nonpaved areas were found to be higher than those of the paved areas, and the dose rates of the paved areas depend on the paving materials of the area. The contamination level of the nonpaved area in Nasushiobara City was below the regulation level of specific activities in a radiation-controlled area in Japan. However, the contamination levels in the nonpaved areas in Fukushima City and Koriyama City were above the regulation level. © 2011 Atomic Energy Society of Japan, All Rights Reserved.
  • 中高エネルギー重荷電粒子に対するGSO(Ce)シンチレータの応答, 古場裕介, 今村稔, 古場尚雅, 大川仁志, 嶋津拓郎, 金子素久, 山下雄介, 岩元大樹, 福田博明, 金政浩, 芳原新也, 魚住裕介, 若林源一郎, 松藤成弘, 池田伸夫, UTNL-R(東京大学大学院工学系研究科附属原子力工学研究施設), UTNL-R(東京大学大学院工学系研究科附属原子力工学研究施設), (0449), 45 - 46, 2006
  • Thermal Neutron Flux Measurement by Counting Conversion Electrons from 134mCs Generated in a CsI Scintillator, Miyu Shimazu, Genichiro Wakabayashi, Akihiro Nohtomi, Yusuke Koba, Kiyomitsu Shinsho, 2018 IEEE Nuclear Science Symposium and Medical Imaging Conference, NSS/MIC 2018 - Proceedings, 2018 IEEE Nuclear Science Symposium and Medical Imaging Conference, NSS/MIC 2018 - Proceedings, Nov. 2018
    Summary:© 2018 IEEE. A new method to measure low intensity neutrons such as secondary neutrons generated in radiotherapy has been developed. In the proposed method, thermal neutron flux is determined by measuring the conversion electrons from 134mCs generated in a CsI(Tl) scintillator irradiated by neutrons. Because the generated 134mCs is contained in the scintillator as internal sources, the emitted conversion electrons fully stop in the scintillator and counted with high efficiency. The thermal neutron flux in the neutron radiography facility of the Kindai University's research reactor, UTR-KINKI, was measured by the proposed method. The cadmium difference method was used to separate the contributions of thermal and epi-thermal neutrons. The result was in good agreement with the one obtained by the conventional gold foil activation method. It was concluded that the proposed method is useful for the measurement of thermal neutron flux.
  • Dose linearity and linear energy transfer dependence of Cr-doped Al2O3 ceramic thermoluminescence detector, Yusuke Koba, Risa Shimomura, Weishan Chang, Kiyomitsu Shinsho, Shin Yanagisawa, Genichiro Wakabayashi, Kazuki Matsumoto, Hiroaki Ushiba, Takayuki Ando, Sensors and Materials, Sensors and Materials, 30(7), 1599 - 1604, 2018 , Refereed
    Summary:© MYU K.K. A Cr-doped alumina (Al2O3:Cr) ceramic thermoluminescent detector (TLD) has the potential to be applied as a two-dimensional (2D) imaging device in radiation therapy. In this work, we investigated the linearity in the dose level of radiotherapy and the linear energy transfer (LET) dependence of Al2O3:Cr ceramic TLD using several species of heavy charged particles (HCPs). The Al2O3:Cr ceramic TLD had good linearity as a function of irradiation dose. However, the large LET-dependent response made it difficult to apply the detector directly to dose measurement in HCP therapy. The combination of two Al2O3 ceramic TLDs, one with Cr doping and one without Cr doping, may be expected to be applied to the measurement of LET distributions because of the different LET dependences.
  • Preliminary design study of a simple neutron energy spectrometer using a CsI self-activation method for daily QA of accelerator-based BNCT, Ryosuke Kurihara, Akihiro Nohtomi, Genichiro Wakabayashi, Yoshinori Sakurai, Hiroki Tanaka, Journal of Nuclear Science and Technology, Journal of Nuclear Science and Technology, 2018 , Refereed
  • Shape distortion of I-128 beta(-) spectrum observed by a self-activated CsI(Tl) scintillator for high-sensitivity neutron measurements, Soichiro Honda, Akihiro Nohtomi, Keita Machidori, Genichiro Wakabayashi, NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT, NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT, 871, 148 - 153, Nov. 2017 , Refereed
    Summary:The factors causing the distortion of the I-128 beta(-) spectrum detected by a self-activated CsI(Tl) scintillator were studied to verify the correctness of the spectral shape and the appropriateness of the discrimination setting for beta(-)- particle counting by the scintillator. These criteria are essential for the correct evaluation of radioactivity generated in a scintillator volume by the self-activation method, which was recently proposed by our group. A pulse height defect caused by the partial escape of beta(-) particles from the surface of the scintillator crystal shifts the beta(-) spectrum toward the lower-energy region when smaller CsI(Tl) scintillators are used (the beta(-)- escape effect). For larger CsI(Tl) scintillators, an increase in pulse height caused by the summing of 0.443 MeV prompt gamma- rays from the excited state of the 128I daughter nuclide (Xe-128) affects the shape of the beta(-) spectrum considerably, resulting in a shift toward the higher-energy region (the gamma- summing effect). The extent of the contributions of these two effects was examined by a Monte Carlo simulation of various cubical CsI(Tl) crystals of different sizes. It was found that the distortions caused by those two effects effectively cancel each other out for a medium-size cubical CsI(Tl) crystal with a side length of approximately 3 cm. This finding is very useful for the practical applications of the self-activation method. In addition to the factors mentioned above, the efficiency of scintillation light collection by the photodetectors also affects the shape distortion of the beta(-) spectrum slightly through spectral line broadening due to the degradation of the energy resolution. This effect was estimated using a simple model with different discrimination settings for beta(-) pulse counting. (C) 2017 Elsevier B.V. All rights reserved.
  • X-ray imaging using the thermoluminescent properties of commercial Al2O3 ceramic plates, Kiyomitsu Shinsho, Yasuyuki Kawaji, Shin Yanagisawa, Keisuke Otsubo, Yusuke Koba, Genichiro Wakabayashi, Kazuki Matsumoto, Hiroaki Ushiba, APPLIED RADIATION AND ISOTOPES, APPLIED RADIATION AND ISOTOPES, 111, 117 - 123, May 2016 , Refereed
    Summary:This research demonstrated that commercially available alumina is well-suited for use in large area X-ray detectors. We discovered a new radiation imaging device that has a high spatial resolution, high sensitivity, wide dynamic range, large imaging area, repeatable results, and low operating costs. The high thermoluminescent (TL) properties of Al2O3 ceramic plates make them useful for X-ray imaging devices. (C) 2016 Elsevier Ltd. All rights reserved.
  • Absorbed dose estimation using LET dependence in glow curve of thermoluminescent phosphor Li3B7O12:Cu in therapeutic carbon beams, Weishan Chang, Yusuke Koba, Shigekazu Fukuda, Genichiro Wakabayashi, Hidetoshi Saitoh, Kiyomitsu Shinsho, JOURNAL OF NUCLEAR SCIENCE AND TECHNOLOGY, JOURNAL OF NUCLEAR SCIENCE AND TECHNOLOGY, 53(12), 2028 - 2033, 2016
    Summary:A high temperature ratio (HTR) method has been proposed to correct the linear energy transfer (LET) dependence of thermoluminescent (TL) efficiency. To realize the use of the slab-type thermoluminescence detector (TLD) that based on the phosphor Li3B7O12:Cu for heavy charged particle beam, the HTR method has been considered. To improve the reproducibility of HTR, the slow heating rate method is introduced in this report and the coefficient variations of HTR decreased from 10%-20% to 8%. The relation between TL-efficiency, HTR, and LET for Li3B7O12:Cu was manifested and the TL-efficiency as a function of HTR was derived in an attempt to measure the absorbed dose without LET information. The feasibility of the HTR method in therapeutic carbon beams was evaluated by comparing the dose estimated by Li3B7O12:Cu and by an ionization chamber. The accuracy of dose estimation in carbon beams was improved by using the HTR method, but there is room for further improvement. The use of Li3B7O12:Cu in heavy charged particle beams can be materialized with further improvement of HTR sensitivity.
  • Accuracy of neutron self-activation method with iodine-containing scintillators for quantifying I-128 generation using decay-fitting technique, Akihiro Nohtomi, Genichiro Wakabayashi, NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT, NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT, 800, 6 - 11, Nov. 2015 , Refereed
    Summary:We evaluated the accuracy of a self activation method with iodine containing scintillaLors in quantifying 1281 generation in an activation detector; the self-activation method was recently proposed for photo-neutron on-line measurements around X-ray radiotherapy machines. Here, we consider the accuracy of determining the initial count rate R-0, observed just after termination of neutron irradiation of the activation detector. The value R-0 is directly related to the amount or activity generated by incident neutrons; the detection efficiency of radiation emitted from the activity should be taken into account for such an evaluation. Decay curves of I-128 activity were numerically simulated by a computer program for various conditions including different initial count rates (R-0) and background rates (R-B), as well as counting statistical fluctuations. The data points sampled at minute intervals and integrated over the same period were fit by a non-linear least-squares filling routine to obtain the value R-0 as a fitting parameter with an associated uncertainty. The corresponding background rate R-B was simultaneously calculated in the same fitting routine. Identical data sets were also evaluated by a well-known integration algorithm used for conventional activation methods and the results were compared with those of the proposed fitting method. When we fixed R-B = 500 cpm, the relative uncertainty sigma(R0)/R-0 <= 0.02 was achieved for R-0 R-B >= 20 with 20 data points from 1 min to 20 min following the termination of neutron irradiation used in the fitting; sigma(R0)/R-0 <= 0.01 was achieved for R-0/R-B >= 50 with the same data points. Reasonable relative uncertainties to evaluate initial count rates were reached by the decay-fitting method using practically realistic sampling numbers. These results clarified the theoretical limits of the fitting method. The integration method was found to be potentially vulnerable to short-term variations in background levels, especially instantaneous contaminations by spike-like noise. The fitting method easily detects and removes such spike-like noise. (C) 2015 Elsevier B.V. All rights reserved.
  • Applicability of self-activation of an NaI scintillator for measurement of photo-neutrons around a high-energy X-ray radiotherapy machine, Genichiro Wakabayashi, Akihiro Nohtomi, Eriko Yahiro, Toshioh Fujibuchi, Junichi Fukunaga, Yoshiyuki Umezu, Yasuhiko Nakamura, Katsumasa Nakamura, Makoto Hosono, Tetsuo Itoh, Radiological Physics and Technology, Radiological Physics and Technology, 8(1), 125 - 134, 2015 , Refereed
    Summary:The applicability of the activation of an NaI scintillator for neutron monitoring at a clinical linac was investigated experimentally. Thermal neutron fluence rates are derived by measurement of the I-128 activity generated in an NaI scintillator irradiated by neutrons β-rays from I-128 are detected efficiently by the NaI scintillator. In order to verify the validity of this method for neutron measurement, we irradiated an NaI scintillator at a research reactor, and the neutron fluence rate was estimated. The method was then applied to neutron measurement at a 10-MV linac (Varian Clinac 21EX), and the neutron fluence rate was estimated at the isocenter and at 30 cm from the isocenter. When the scintillator was irradiated directly by high-energy X-rays, the production of I-126 was observed due to photo-nuclear reactions, in addition to the generation of I-128 and Na-24. From the results obtained by these measurements, it was found that the neutron measurement by activation of an NaI scintillator has a great advantage in estimates of a low neutron fluence rate by use of a quick measurement following a short-time irradiation. Also, the future application of this method to quasi real-time monitoring of neutrons during patient treatments at a radiotherapy facility is discussed, as well as the method of evaluation of the neutron dose.
  • THERMOLUMINESCENT RESPONSES OF Li3B7O12:Cu TO PROTON BEAM, Y. Koba, K. Shinsho, S. Tamatsu, S. Fukuda, G. Wakabayashi, RADIATION PROTECTION DOSIMETRY, RADIATION PROTECTION DOSIMETRY, 161(1-4), 437 - 440, Oct. 2014 , Refereed
    Summary:A thermoluminescent (TL) phosphor Li3B7O12:Cu was irradiated by a proton beam at NIRS-HIMAC in Japan. Irradiation was performed at different water-equivalent depths using range shifters made of polymethyl methacrylate. The thermoluminescent responses of Li3B7O12:Cu were analysed, focusing on the TL efficiency and glow curve. The irradiated samples were heated from room temperature to 200 degrees C at 0.16 degrees C s(-1). The high-temperature area of the glow curve under proton irradiation changed in comparison with that under Co-60 gamma-ray irradiation. The relative TL efficiency of the main peak slightly varied between 0.8 and 1.1. The relationship between the relative TL efficiency of the main peak and the high-temperature area ratio (HTR) value, the relative TL ratio of the main peak to the high-temperature area, showed approximate linearity for proton dosimetry. Using correction based on the HTR method, the TL phosphor Li3B7O12:Cu can become a useful dosimetric tool for therapeutic proton beams.
  • Basic characteristics of tissue-equivalent phantom thermoluminescence slab dosimeter using new TL phosphor Li3B7O12:Cu, Kiyomitsu Shinsho, Yusuke Koba, Genichiro Wakabayashi, Satoshi Tamatsu, Shigekazu Fukuda, Ryo Morimoto, Daiki Maruyama, Hidetoshi Saitoh, Noboru Sakurai, RADIATION MEASUREMENTS, RADIATION MEASUREMENTS, 62, 15 - 21, Mar. 2014 , Refereed
    Summary:Here we investigate the basic characteristics of the tissue-equivalent phantom thermoluminescence slab dosimeter with synthetic resin type 1 (TEP-TLSD/SR1), a two-dimensional TLD based on TL phosphor Li3B7O12:Cu developed by the Urushiyama Research Group. Li3B7O12:Cu has a single glow peak at 120 degrees C at a heating rate of 0.317 degrees C s(-1). The dose response is linear between 0.1 and 10 Gy. The phosphor, when combined with a synthetic resin, can be molded into 200 mm x 200 mm x 2.5 mm slabs. The system has a Charge Coupled Device (CCD) dependent spatial resolution (pixel pitch) of 640 mu m and a pixel response standard deviation of 1.33%. Using simple pixel-based noise compensation, we were able to improve the signal-to-noise ratio (SNR) in the final image. In tests as a TEP, this system gives off axis ratio and percentage dose depth results highly correlated with those of an ion chamber suspended in a water phantom. The TEP-TLSD/SR1 produces similar images to Gafchromic film for X-ray imaging. This TEP-TLSD/SR1 is not only larger than the prototype, but also has a better SNR and improved usability. With further improvements in tissue equivalence, we foresee a system where a TEP and dosimeter are combined into a three-dimensional dosimeter. (C) 2014 Elsevier Ltd. All rights reserved.
  • Time trend change of air dose rate on Paved areas in Fukushima city after the Fukushima Daiichi NPP accident, Sin-Ya Hohara, Masayo Inagaki, Hirokuni Yamanishi, Genichiro Wakabayashi, Wataru Sugiyama, Tetsuo Itoh, Radiation Monitoring and Dose Estimation of the Fukushima Nuclear Accident, Radiation Monitoring and Dose Estimation of the Fukushima Nuclear Accident, 103 - 113, Jan. 01 2014 , Refereed
    Summary:The Kinki University Atomic Energy Research Institute investigated radioactive contamination resulting from the Fukushima Daiichi Nuclear Power Plant accident in urban areas of Fukushima City, Fukushima Prefecture, Japan. Activity measurement of the surface soil and a survey of the dose rate distribution in urban areas were performed. From the results of this research, dose rate changes in paved areas became clear, and gradients of the dose rate decrease for different paving materials were measured and analyzed.
  • Recent activities in the field of radiation measurement and nuclear data, Genichiro Wakabayashi, Yusuke Uozumi, Journal of Nuclear Science and Technology, Journal of Nuclear Science and Technology, 50(12), 1127 - 1128, Dec. 01 2013 , Refereed
  • Response of a plate-type thermoluminescence dosimeter to a therapeutic carbon beam, Yusuke Koba, Shigekazu Fukuda, Kiyomitsu Shinsho, Genichiro Wakabayashi, Satoshi Tamatsu, JOURNAL OF THE KOREAN PHYSICAL SOCIETY, JOURNAL OF THE KOREAN PHYSICAL SOCIETY, 63(7), 1432 - 1436, Oct. 2013 , Refereed
    Summary:In order to measure the three-dimensional dose distribution in X-ray radiotherapy, we developed a plate-type thermoluminescence dosimeter (TLD) using the TL phosphor Li3B7O12:Cu, which has Z (eff) = 7.42 and a density of 1.01 gcm(-3). This detector was expected on useful application in advanced X-ray radiotherapies such as intensity-modulated ratiation therapy (IMRT) etc., because it can obtain 3D dose measurements simply and quickly with a single exposure. In this paper, we report the response of this plate-type TLD to a therapeutic carbon beam at the Heavy Ion Medical Accelerator in Chiba (HIMAC). Using a plate heater and charge coupled device (CCD) camera, we captured thermoluminescence images of plate-type TLDs irradiated by a therapeutic carbon beam. The TL intensity was measured at each water equivalent depth and compared with output of the ionization chamber. The relative TL efficiency of this TLD as Co-60 gamma-ray equivalent decreased gradually with increasing dose-averaged linear-energy-transfer (LET), reaching about 20% at the Bragg peak of 290 MeV/u carbon ions.
  • Deuteron-production double-differential cross sections for 300- and 392-MeV proton-induced reactions deduced from experiment and model calculation, Yusuke Uozumi, Yusuke Sawada, Aleksandre Mzhavia, Sho Nogamine, Hiroki Iwamoto, Tadahiro Kin, Shinya Hohara, Genichiro Wakabayashi, Masahiro Nakano, Physical Review C - Nuclear Physics, Physical Review C - Nuclear Physics, 84(6), Dec. 27 2011 , Refereed
    Summary:Deuteron production from intermediate-energy proton-nucleus interactions was investigated through experiments and model calculations, mainly to develop a theoretical model by elucidating the mechanism of cluster production. Spectral double-differential cross sections were measured for inclusive (p,dx) reactions on five targets in the periodic table, namely 12C, 27Al, 51V, 93Nb, and 197Au, at beam energies of 300 and 392 MeV. The cross sections were determined in almost the entire outgoing energy range from the highest down to 30 MeV and at laboratory angles from 20 to 104. To interpret the measured spectra, we proposed a new model that includes the nucleon correlations of the initial- and final-state interactions to describe cluster knockout and pickup within the intranuclear cascade model. The results of the model calculations showed reasonable agreements with those of the experiments. Moreover, the model indicated reasonable predictive power for the (p,3Hex), (p,αx), and (d,d′x) reactions measured elsewhere. The quantum molecular dynamics model underpredicts the results of the experiments by two to three orders except for low-energy portions of the (p,dx) spectra. © 2011 American Physical Society.
  • Study of light charged particle production double differential cross sections from proton-actinide reactions at 360 MeV, A. Mzhavia, M. Ueyama, Y. Uozumi, Y. Sawada, M. Yoshioka, G. Wakabayashi, H. Iwamoto, Y. Koba, Z. Tsamalaidze, P. Evtukhovitch, V. Kalinnikov, N. Khomutov, N. Kuchinskii, G. Macharashvili, A. Moiseenko, A. Molokanov, V. Samoilov, Journal of the Korean Physical Society, Journal of the Korean Physical Society, 59(23), 1945 - 1948, Aug. 2011 , Refereed
    Summary:Double-differential cross section (DDX) data of nucleon-actinide reactions is crucial for the study of nuclear waste transmutation by accelerator driven systems. Charged particle emission data is strongly required as well as the neutron data up to several Gev. In the present study, we measured double-differential cross sections of light charged particle productions for proton induced reactions on 232 Th at 360 MeV. The experiment was carried out at the PHASOTRON facility of the Joint Institute for Nuclear Research (JINR) in Dubna. The light charged particles (LCPs) emitted from nuclear reactions were detected by ΔE-E counter telescopes. Eight detector systems were used. Four of them were comprised of two plastic scintillator plates and BGO crystal. The other four consisted of two silicon semiconductor detectors and two scintillation counters, a cubic CsI(TI) (40 mm long) crystal and plate plastic scintillator. The four identical detectors on each side were placed at laboratory angles of 20°, 40°, 70° and 105° with respect to the beam axis. Resultant DDX spectra of protons and deuterons were compared with intranuclear cascade (INC) model.
  • Measurement of proton-production double differential cross sections by 290 MeV/u carbon beams on C, Cu, Pb targets at forward angles, K. Tahara, Y. Fukuda, G. Wakabayashi, H. Ban, Y. Morimoto, M. Yoshioka, K. Kiyohara, Y. Koba, H. Iwamoto, Y. Uozumi, N. Matsufuji, Journal of the Korean Physical Society, Journal of the Korean Physical Society, 59(23), 1840 - 1843, Aug. 2011 , Refereed
    Summary:We measured proton-production double differential cross sections (DDXs) by 290 MeV/u carbon beams on carbon, copper, lead targets at forward angles. The proton energies were measured with the spectrometer which consisted of GSO(Ce) crystals and plastic scintillators. The measured DDXs were compared with the calculated ones with PHITS code. The simulation results generally agreed with the measured ones. The measured results will be useful as the benchmark of existing simulation codes and for the future improvements.
  • A method of neutron energy evaluation by using an imaging plate and cone-like acryl converters with a geometrical modulation concept, A. Nohtomi, N. Sugiura, T. Itoh, G. Wakabayashi, T. Sakae, T. Terunuma, K. Yabuta, M. Tamura, T. Fujibuchi, T. Takata, K. Kume, NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT, NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT, 633(1), 36 - 45, Mar. 2011 , Refereed
    Summary:Cone-like acryl converters have been used for transforming the energy-distribution information of incident fast neutrons into the spatial-distribution information of recoil protons. The characteristics of neutron-proton conversion have been studied up to around 10 MeV by using an imaging plate (IP). A notable and interesting signal enhancement due to recoil protons generated in an acryl converter was observed on IP images for irradiation with a (252)Cf source. Similar experiments were also performed in the radiation field of a research nuclear reactor and an accelerator-based neutron generator. A Monte Carlo calculation was carried out in order to understand the spatial distributions of the signal enhancement by recoil protons; these distributions promisingly involve the energy information of incident neutrons in principle. Consequently, it has been revealed that the neutron energy evaluation is surely possible by analyzing the spatial distributions of signal enhancement that is caused by recoil protons. (C) 2011 Elsevier B.V. All rights reserved.
  • Application of high-energy photon CT system with laser-compton scattering to nondestructive test, Hiroyuki Toyokawa, Hiroshi Ogawa, Ryunosuke Kuroda, Hisashi Kanada, Taketo Uomoto, Takeshi Kaihori, Kenichi Watanabe, Genichiro Wakabayashi, Kawakatsu Yamada, IEEE Nuclear Science Symposium Conference Record, IEEE Nuclear Science Symposium Conference Record, 2, 1598 - 1602, 2007 , Refereed
    Summary:A CT system using high-energy monochromatic photons is one of the best choices for nondestructive test of industrial products. We have developed a CT system for nondestructive test of industrial products using the laser-Compton photons, which were generated with an electron accelerator and conventional commercial laser system. We measured the profile, and found that they were a 0.8 - 1.5 mm in diameter. We also applied the CT system to the nondestructive test of the concrete specimen, and successfully obtained the CT image. © 2007 IEEE.
  • Light output response of LYSO(Ce) crystal to relativistic helium and carbon ions, Yusuke Koba, Genichiro Wakabayashi, Minora Imamura, Yusuke Uozumi, Naoya Koba, Hiroki Iwamoto, Hitoshi Ohkawa, Takuro Shimazu, Naruhiro Matsufuji, Petr Evtoukhovitch, Vladimir Kalinnikov, Nikolay Khomutov, Nikolay Kuchinskii, Anatoly Moiseenko, David Mzavia, Valentin Samoilov, Zviad Tsamalaidze, IEEE Nuclear Science Symposium Conference Record, IEEE Nuclear Science Symposium Conference Record, 3, 2303 - 2306, 2007 , Refereed
    Summary:The light output response of LYSO(Ce) crystals was investigated using helium and carbon beams of 720 MeV and 3.48 GeV, respectively. Experimental results showed good agreement with the calculated curves by the Birks equation but the values of the parameters in the equation were different between helium and carbon ions. © 2007 IEEE.
  • Light output response of GSO(Ce) crystals to relativistic carbon ions, Genichiro Wakabayashi, Yusuke Koba, Minoru Imamura, Yusuke Uozumi, Naoya Koba, Takuro Shimazu, Motohisa Kaneko, Hitoshi Ohkawa, Nobuo Ikeda, Tadahiro Kin, Naruhiro Matsufuji, IEEE Nuclear Science Symposium Conference Record, IEEE Nuclear Science Symposium Conference Record, 2, 1175 - 1177, 2007 , Refereed
    Summary:We have investigated the light output response of a GSO(Ce) crystal to carbon ions of energy up to 3.34 GeV. An experiment was carried out with HIMAC at National Institute of Radiological Sciences in Chiba, Japan. The incident energy of carbon beam was changed by inserting target materials with different thicknesses as degraders. Experimental results were consistent with the calculated curve by Birks equation, and the light output plotted as a function of deposited energy in the GSO(Ce) crystal showed a slight non-linearity in the low energy region and a good linearity in the higher energy region above around 1.5 GeV. © 2006 IEEE.
  • Low-level radiation measurement system with magnetically levitated electrode ionization chamber detector, T. Kawaguchi, K. Futagami, M. Matoba, G. Wakabayashi, N. Ikeda, Y. Uozumi, N. Yamanaka, M. Kaneko, IEEE Transactions on Nuclear Science, IEEE Transactions on Nuclear Science, 53(4), 2276 - 2280, Aug. 2006 , Refereed
    Summary:An automatic system was developed for the measurement of radiation using a magnetically levitated electrode ionization chamber. The system was used to measure background and 40 K gamma ray dose rates. The background dose rate measurement demonstrated high sensitivity and reliability of the system, and a low-level 40K gamma ray dose rate was successfully measured. For the case of a 30-minute measurement, the detection limit of the system is 13 nGy/h. This measurement system will be useful as an area monitor to measure space dose rates. © 2006 IEEE.
  • Response characteristics of GSO(Ce) crystal to intermediate-energy alpha-particles, M. Imamura, Y. Yamashita, P. Evtoukhovitch, S. Hohara, V. Kalinikov, W. Kallies, N. Khumutov, T. Kin, N. Kuchinski, D. Maki, N. Matsufuji, A. Moisenko, D. Mzavia, V. Samoilov, Z. Tsamalaidze, Y. Uozumi, G. Wakabayashi, NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT, NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT, 564(1), 324 - 327, Aug. 2006 , Refereed
    Summary:Characteristics of a GSO(Ce) crystal were investigated in terms of the light output response and the peak-to-total efficiency for impinging intermediate-energy a-particles. Experiments were carried out using a-particles of energies ranging from 143 to 718 MeV with primary a beams of 400 and 718 MeV. It has been demonstrated that the experimental results are explained well by calculations in the same manner as for protons and deuterons. In particular, no particle identity dependence of scintillation quenching phenomena have been observed between protons, deuterons and a-particles. Furthermore, good linearity is confirmed in the higher energy range up to 718 MeV. The peak-to-total efficiency was accounted for by calculations using a-nucleus reaction cross-sections. (c) 2006 Elsevier B.V. All rights reserved.
  • Proton production cross sections for reactions induced by 300- and 392-MeV protons, T. Kin, S. Hohara, F. Saiho, K. Ikeda, K. Ichikawa, Y. Yamashita, M. Imamura, G. Wakabayashi, N. Ikeda, Y. Uozumi, M. Matoba, N. Koori, AIP Conference Proceedings, AIP Conference Proceedings, 769, 207 - 210, May 24 2005 , Refereed
    Summary:Multistep direct processes in proton production reactions were investigated with proton beam of 300- and 392-MeV bombarding targets nuclei. The targets nuclei are 181Ta, 197Au, and 209Bi for 392 MeV and 197Au for 300 MeV protons. Energy spectra were measured at several laboratory angles from 20° to 105° and compared with two theoretical models, the quantum molecular dynamics and the intranuclear cascade model. At intermediate energy, the double differential cross section is sensitive to ground state in codes. We found that a more realistic ground state led better accounting of measured data. © 2005 American Institute of Physics.
  • Proton production cross sections for reactions by 300- and 392-MeV protons on carbon, aluminum, and niobium, Tadahiro Kin, Fuminobu Saiho, Shinya Hohara, Katsuhiko Ikeda, Kiyohisa Ichikawa, Yusuke Yamashita, Minoru Imamura, Genichiro Wakabayashi, Nobuo Ikeda, Yusuke Uozumi, Masaru Matabo, Masahiro Nakano, Norihiko Koori, Physical Review C - Nuclear Physics, Physical Review C - Nuclear Physics, 72(1), 2005 , Refereed
    Summary:Proton productions from proton induced reactions have been investigated for target nuclei of C12, Al27, and Nb93 at 300 and 392 MeV. Proton inelastic continua over a broad energy range were measured at laboratory angles from 20° to 105°. The differential cross sections were compared with two theoretical models, the quantum molecular dynamics (QMD) and the intranuclear cascade (INC) model in terms of the multistep direct process. We demonstrated that consistencies of these models can be improved using a realistic ground state of target nucleus, and that the INC model developed presently has a fairly good consistency and a higher predictive ability than the QMD. © 2005 The American Physical Society.
  • The 96Mo(p→,d)95Mo reaction at 50 MeV, S. A. Sultana, D. Maki, G. Wakabayashi, Y. Uozumi, N. Ikeda, Syafarudin, F. Aramaki, T. Kawaguchi, M. Matoba, H. M. Sen Gupta, Physical Review C - Nuclear Physics, Physical Review C - Nuclear Physics, 70(3), 0346121 - 03461215, 2004 , Refereed
    Summary:The 96Mo(p,d)95Mo reaction has been studied with a 50 MeV polarized beam. Differential cross sections and analyzing powers have been measured for investigating the level structure in 95Mo up to the excitation energy of 5.8 MeV. The standard distorted-wave Born approximation theory provides transfer angular momentum values and spectroscopic factors for the excited states. Furthermore, the theoretical analysis is extended also for the continuum region with a direct reaction model. Experimental double differential cross sections for continuum spectra are predicted well by adopting an asymmetric Lorentzian form for the response function in the distorted wave Born approximation based cross section calculations.
  • Evaluation of the self-absorption of 14C beta-rays in gel-suspension samples by Monte Carlo simulation, G. Wakabayashi, K. Nagao, T. Okai, M. Matoba, Journal of Radioanalytical and Nuclear Chemistry, Journal of Radioanalytical and Nuclear Chemistry, 255(3), 585 - 590, Mar. 01 2003 , Refereed
    Summary:In order to investigate the self-absorption of the β-mys from 14C in a gel-suspension sample, the Monte Carlo code, simulating the sequence of stages occurring in the sample, has been developed. The trajectory of the electron was calculated by the continuous slowing down approximation and the multiple Coulomb scattering theory. The effects of the self-absorption, strong quenching and particle size distribution of calcium carbonate on the output counting efficiency and the shape of the energy spectrum were evaluated.
  • Measurement of subcritical reactivity in unsteady state with digital time-series data acquisition system using difference filter technique, Genichiro Wakabayashi, Yujiro Yonemura, Hiroaki Heguri, Masaru Matoba, Takeji Sakae, Kengo Hashimoto, T. Horiguchi, IEEE Transactions on Nuclear Science, IEEE Transactions on Nuclear Science, 49(5), 2508 - 2512, Oct. 2002 , Refereed
    Summary:The Digital Time-Series Data Acquisition System using first-in-first-out (FIFO) memory module has been developed for the monitoring of subcritical reactivity. The system records arriving time of the signal from a neutron detector, and time-series data are saved in a personal computer (PC). Using this system, the measurement of time-series data is carried out more efficiently than that using a conventional multichannel scaler (MCS) system, and it has been applied for the monitoring of subcritical reactivity of the reactor in a steady state using the conventional Feynman-α technique. In the present work, this system was applied for the monitoring of subcritical reactivity in an unsteady state using the difference filter technique. The test experiment was carried out with the research reactor of Atomic Energy Institute of Kinki University, Japan. From the experimental results, it was shown that the present system was useful for the continuous monitoring of varying subcritical reactivity by application of the difference filter technique.
  • Continuum spectra in one-nucleon transfer reactions —(p→, d) reactions at medium energy region—, S. Syafarudin, Fujio Aramaki, Genichiro Wakabayashi, Yusuke Uozumi, Nobuo Ikeda, Masaru Matoba, Katsuhiro Yamaguchi, Takeji Sakae, Norihiko Koori, Takashi Maki, Journal of Nuclear Science and Technology, Journal of Nuclear Science and Technology, 39, 377 - 380, 2002 , Refereed
    Summary:The continuum spectra up to about 20 MeV of the (p. d) reactions induced by 65 and 21 MeV polarized protons have been analyzed using such an approach as proposed by Lewis. An asymmetry Lorentzian form strength function was employed in the analysis, in set with empirical spreading widths. The cross sections were estimated as an incoherent sum of many shell-orbits constituents based on the distorted-wave Bom approximation (DWBA). The comparisons between the theoretical and experimental results of cross section angular distribution indicate a systematic relation between the distribution of strength and the target mass number, in isotopes. © 2014 Atomic Energy Society of Japan. All Rights Reserved.
  • Study of proton and deuteron spectra from proton induced reactions at intermediate energies, Fuminobu Saiho, Junji Tanakal, Shinya Hohara, Bin Cao, Shozo Aoki, Yusuke Uozumi, Genichiro Wakabayashi, Masaru Matoba, Takashi Maki, Masahiro Nakano, Norihiko Kooru, Journal of Nuclear Science and Technology, Journal of Nuclear Science and Technology, 39, 246 - 249, 2002 , Refereed
    Summary:Intermediate-energy nucleon-nucleus interactions were investigated in order to achieve a more comprehensive understanding of spallation reaction and heavier fragments productions. Measurements of proton and deuteron production reactions for 300- and 392 MeV proton incidence were carried out at RCNP ring-cyclotron facility. Inclusive 12C(p, p’x) and 12C(p, dx) spectra at 300 MeV were measured in a wide energy range and compared with two theoretical calculations: the quantum molecular dynamics model and the intranuclear cascade model. The calculations of the INC model were in good agreement with the experimental results in the quasifree region. The deuteron production cross sections calculated by the QMD model were much smaller than the ones obtained by the measurement. The cause of this discrepancy was discussed in terms of a deuteron knockout process. © 2014 Atomic Energy Society of Japan. All Rights Reserved.
  • Proton production cross sections for reactions induced by 300- and 392-mev protons, Yusuke Uozumi, Fuminobu Saiho, Tadahiro Kin, Shinya Hohara, Syouzo Aoki, Bin Cao, Junzi Tanaka, Genichiro Wakabayashi, Masaru Matoba, Masahiro Nakano, Takashi Maki, Norihiko Kooru, Journal of Nuclear Science and Technology, Journal of Nuclear Science and Technology, 39, 385 - 388, 2002 , Refereed
    Summary:Multistep direct processes in proton production reactions were investigated with proton beams of 300 and 392 MeV bombarding five target nuclei, 12C, 160, 27Al, 93Nb and 197Au. Energy spectra were measured at eleven laboratory angles from 19 deg to 104 deg and compared with two theoretical models, the quantum molecular dynamics and the intranuclear cascade model. © 2014 Atomic Energy Society of Japan. All Rights Reserved.
  • Readout responses of inclined strips in position-sensitive detectors, F. Javanmardi, G. Wakabayashi, A. Minuchehr, A. Zolfaghari, M. M. Rashid, M. Matoba, IEEE Transactions on Nuclear Science, IEEE Transactions on Nuclear Science, 48(6), 2321 - 2323, Dec. 2001 , Refereed
    Summary:Readout responses for the inclined strips in position-sensitive detectors have been studied using theoretical predictions and experimental results. Inclined strips are almost along the displacement direction of incident particles. Rotating conventional strips to near horizontal strips decreases the number of strips by a tangential factor for long-length position sensing. In addition to the channel reduction, the inclined strips modify about 10% in the readout linearity compared to the long-length zigzag patterns. There is resolution degradation because of the inherent high sensitivity of these strips to the avalanche size (about 8% of the detector full length). Double peak responses were observed for sensing the positions of the incident particles. Our theoretical predictions and experimental results are discussed in this paper.
  • A ray-trace-type counter telescope for neutron spectrometry, G. Wakabayashi, T. Kitano, H. Yanagawa, S. Aoki, M. Matoba, T. Sakae, Y. Watanabe, K. Sagara, N. Ikeda, IEEE Transactions on Nuclear Science, IEEE Transactions on Nuclear Science, 48(3 I), 320 - 324, Jun. 2001 , Refereed
    Summary:A compact recoil-proton counter telescope with two position sensitive proportional counters (PSPCs) for neutron spectrometry has been developed. This counter telescope consists of a radiator (a thin polyethylene film), two PSPCs used as ΔE detector, and an Si-SSD used as E detector. Using the position information extracted from two PSPCs, the three-dimensional trajectory of the recoil proton and the recoil angle can be determined event by event. The performance of this counter telescope was tested by the measurement of 7.2-MeV neutrons produced from D-D reactions. It was shown that the energy spectra of neutrons could be obtained by determining the energy of each incident neutron using a recoil angle.
  • Isobaric analog states observed in the 58Ni(p,d)57Ni reaction with 65 MeV polarized protons, H. M. Sen Gupta, Syafarudin, S. Aoki, F. Aramaki, M. Matoba, Y. Uozumi, G. Wakabayashi, T. Sakae, N. Koori, T. Maki, M. Nakano, Y. Fujita, M. Fujiwara, H. Ikegami, I. Katayama, S. Morinobu, T. Yamazaki, Physical Review C - Nuclear Physics, Physical Review C - Nuclear Physics, 63(1), 176011 - 176014, 2001 , Refereed
    Summary:Isobaric analog states populated in the (p,d) reaction on 58Ni are studied using 65 MeV high resolution protons. Weakly excited analogs assigned previously as confused spin states are found with proper spins and strengths in the background of a number of normal states. Deviation of the excitation energies of analogs from those calculated with the Coulomb displacement energy is found reasonably to be a function of the excitation energy. Possible anti-analogs of the 1f7/2, 2s1/2, and 1d3/2 hole states are observed.
  • Stability and reproducibility of gel-suspension samples for the liquid scintillation counting of 14C using N-lauroyl-L-glutamic-α,γ-dibutylamide, G. Wakabayashi, H. Ohura, T. Okai, M. Matoba, H. Kakiuchi, N. Momoshima, H. Kawamura, Journal of Radioanalytical and Nuclear Chemistry, Journal of Radioanalytical and Nuclear Chemistry, 240(3), 929 - 930, 1999 , Refereed
    Summary:Stability and reproducibility of gel-suspension samples were investigated in order to evaluate the characteristic feature of the gel- suspension method for 14C activity measurement. Commercially available gelling agent, N-lauroyl-L-glutamic-α,γ-dibutylamide, was used for the gel- formation of the samples. No change of the counting rate for the gel- suspension sample was observed for more than 2 years after the sample preparation. Four samples used for checking the reproducibility of the sample preparation method. The same values were obtained for the counting rate of 14C activity within the counting error. No change of the counting rate was observed for the 're-gelated' sample. These results show that the gel- suspension method is appropriate for the 14C activity measurement by the liquid scintillation method and is useful for a long-term preservation of the sample for repeated measurement.
  • Light output response of GSO(Ce) and NaI(Tl) to protons up to 160 MeV, K Anami, H Yoshida, D Konishi, H Murohka, Y Uozumi, G Wakabayashi, A Nohtomi, T Sakae, M Matoba, T Maki, N Koori, NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT, NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT, 404(2-3), 327 - 333, Feb. 1998 , Refereed
    Summary:An experimental study on GSO(Ce) scintillation crystals was made in terms of the light output response to proton in an energy range up to 161 MeV. The experiment was carried out for cubic crystals of 43 mm edge length by using a 392 MeV proton beam. A good linearity was observed between 30 and 161 MeV, and a slight non-linearity below 30 MeV. A relation of dL/dE versus E was determined with stopping protons. A calculation using the relation has agreed with measured pulse heights of protons penetrating the crystal, as well as those of stopping protons. Similar measurements were made for NaI(TI) crystals of 2 in. cubic. Rather large non-linearity was observed in the proton energy range 0-122 MeV. (C) 1998 Elsevier Science B.V. All rights reserved.
  • Response function of a stacked GSO(Ce) spectrometer to cosmic-rays, H. Murohka, K. Anami, G. Wakabayashi, H. Yoshida, A. Nohtomi, Y. Uozumi, T. Sakae, M. Matoba, T. Maki, N. Koori, IEEE Transactions on Nuclear Science, IEEE Transactions on Nuclear Science, 44(3), 484 - 488, 1997 , Refereed
    Summary:The stacked GSO(Ce) spectrometer consists of three plastic scintillation detectors, three rectangular GSO(Ce) scintillators (43×43×43 mm3) and a large cylindrical GSO(Ce) (φ62× 120 mm3). It has been developed to measure proton emission spectra up to 450 MeV. As a preliminary test, γ-rays from 137Cs and cosmic-rays were measured. We compare the results of the stacked GSO(Ce) spectrometer and those of the stacked NaI(Tl) spectrometer. The performances of the stacked GSO(Ce) spectrometer in intermediate energy region are discussed. © 1997 IEEE.

Misc

  • High Sensitive Neutron-detection by using a Self-activation of Iodine-containing Scintillators for the Photo-neutron Monitoring around X-ray Radiotherapy Machines, NOHTOMI Akihiro, WAKABAYASHI Genichiro, KINOSHITA Hiroyuki, HONDA Soichiro, KURIHARA Ryosuke, FUKUNAGA Junichi, UMEZU Yoshiyuki, NAKAMURA Yasuhiko, OHGA Saiji, NAKAMURA Katsumasa, JPS Conference Proceedings (Web), 11, ROMBUNNO.050002 (WEB ONLY),   2016 11 14 , http://jglobal.jst.go.jp/public/201802288266759530
  • 市販セラミックスの熱蛍光特性による放射線イメージング, SHINSHO KIYOMITSU, OSHIMA RINA, KOBA YUSUKE, WAKABAYASHI GEN'ICHIRO, KAWAJI YASUYUKI, FUKUSHI MASAHIRO, 応用物理学会春季学術講演会講演予稿集(CD-ROM), 61st, ROMBUNNO.18A-F1-7,   2014 03 03 , http://jglobal.jst.go.jp/detail.php?from=API&JGLOBAL_ID=201402286987756848
  • Study on Fundamental Properties of a PSF detector by using Monte Carlo Simulation, 八尋絵莉子, 中村祐一, 納冨昭弘, 鳥居建男, 眞田幸尚, 若林源一郎, 伊藤哲夫, 放射線, 39, 1, 25, 29,   2013 09 , http://jglobal.jst.go.jp/public/201302210438609074
  • NaIシンチレータの自己放射化測定にもとづく高感度中性子検出(2), 納冨昭弘, 八尋絵莉子, 中西大樹, 若林源一郎, 藤淵俊王, 梅津芳幸, 福永淳一, 長峰周治, 中村泰彦, 応用物理学会春季学術講演会講演予稿集(CD-ROM), 60th, ROMBUNNO.30A-A5-7,   2013 03 11 , http://jglobal.jst.go.jp/public/201302206546755276
  • NaIシンチレータの自己放射化測定にもとづく高感度中性子検出(1), 若林源一郎, 納冨昭弘, 中西大樹, 藤淵俊王, 応用物理学会春季学術講演会講演予稿集(CD-ROM), 60th, ROMBUNNO.30A-A5-6,   2013 03 11 , http://jglobal.jst.go.jp/public/201302215071015859
  • Time Trend Change of Dose Rate on paved area in Fukushima City, Hohara Sin-ya, Inagaki Masayo, Yamanishi Hirokuni, Wakabayashi Genichiro, Sugiyama Wataru, Itoh Tetsuo, Proceedings of AESJ, 2013, 0,   2013 , 10.11561/aesj.2013s.0.663.0, http://ci.nii.ac.jp/naid/130004568671
    Summary:2011年3月の福島第一原子力発電所事故により放射性物質が一般環境中に放出され、東北・関東地方の空間線量率が上昇した。近畿大学原子力研究所は2011年4月より、福島中通地区における一般環境中の放射性汚染調査を行っている。調査の結果、舗装地においては舗装素材により空間線量率の減衰傾向が異なる事が確認されたので報告をする。
  • Cesium Removal from the Radioactive Cesium Contaminated Soil by an Electrophoresis, Ihara Tatsuhiko, Itoh Tetsuo, Yamanishi Hirokuni, Wakabayashi Genichiro, Hohara Shin-ya, Inagaki Masayo, Proceedings of AESJ, 2013, 0,   2013 , 10.11561/aesj.2013s.0.667.0, http://ci.nii.ac.jp/naid/130004568866
    Summary:放射性セシウム汚染土壌を対象に,化学物質を添加することなく電場の作用で効率よくセシウム除去できる電気泳動的手法を開発した.具体的には負電極板表面にイオン透過膜(セパレーター)を貼り付け,水を加えてスラリー状にした汚染土壌をセパレーターを介して接触させ,負電極の電場によってセパレーターと負電極間界面に引きこみ,除去する方法である.土壌としては学校校庭の表層を集めた土壌を分級し,粒子径0.125 mm以下の区分の土壌を用いた.<br> ラボスケールでの実験として,セパレーターと電極の間にイオン液体とプルシアンブルーの混合物を閉じ込めた系で10 gの土壌用いて泳動電圧100V,30分間電気泳動を行ったところ,30.5&plusmn;0.3 Bq/gを8.3&plusmn;0.2 Bq/gのレベルまで低下できることが分かった.
  • Environmental radiation research in Kawamata-cho, Fukushima -ken, Ito Tetsuo, Murata Yoshiyuki, Furukawa Michiro, Sugiura Nobuyuki, Yamanishi Hirokuni, Horiguchi Tetsuo, Hohara Shinya, Wakabayashi Genichiro, Inagaki Masayo, Kojima Kiyoshi, Proceedings of AESJ, 2011, 0, 831, 831,   2011 , http://ci.nii.ac.jp/naid/130007036161
    Summary:福島県川俣町で環境放射線調査を行なった。NaI(Tl)シンチレーションサーベイメータを用いて空間線量率の状況を把握するとともに、空間線量率の成因を分析するために、土壌を深さ毎に採取した。土壌試料について、ガンマスペクトロメトリで放射性物質濃度を定量した。その主な成分はCs-134とCs-137で、ほぼ同濃度であり、全量の90%以上が、地表面から1cmまで深さにあった。表土除去による空間線量率の低減効果についても確認した。
  • Survey of Radioactive Contaminations in cities at Fukushima-Nakadori area due to Fukushima Daiichi Nuclear Plant Accident, HOHARA SIN-YA, Inagaki Masayo, Kojima Kiyoshi, Yamanishi Hirokuni, Wakabayashi Genichiro, Itoh Tetsuo, Proceedings of AESJ, 2011, 0, 830, 830,   2011 , 10.11561/aesj.2011f.0.830.0, http://ci.nii.ac.jp/naid/130007036162
    Summary:GPS連動型の可搬型放射線位置測定装置を用いて、福島県福島市、福島県郡山市および栃木県那須塩原市の市街地における空間線量率分布の移動測定を行なった。その結果、測定を行なった市街地では、舗装地に比べて非舗装地の空間線量率が高くなる現象が観測された。また、各市街地の非舗装地における表層から0-1cmの土壌の比放射能を測定した結果、福島市内および郡山市内の公園では福島第一原発事故後1ヶ月経過した時点において数量告示に定める放射性同位元素の濃度を超えていた事がわかった。
  • Environmental radiation research in Kawamata-machi, Fukushima Pref.:(2)Reduction of air dose rate by removing suface soil, Wakabayashi Genichiro, Furukawa Michiro, Yamanishi Hirokuni, Sugiura Nobuyuki, Ito Tetsuo, Horiguchi Tetsuo, Hohara Sin-ya, Inagaki Masayo, Kojima Kiyoshi, Murata Yoshiyuki, Proceedings of AESJ, 2011, 0, 832, 832,   2011 , http://ci.nii.ac.jp/naid/130007036168
    Summary:福島県川俣町で環境放射線調査を行なった。学校の校庭や広場においてNaI(Tl)シンチレーションサーベイメータを用いた空間線量率の測定を行って線量の分布を把握した後、地表から約5 mmの表土を除去することにより、空間線量率の低減効果を調べた。学校校庭では半径2 m及び5 m、広場では半径2.4 mの表土を除去した結果、表土を除去した領域の中心で線量率は70~80%に減少した。
  • The Measurement of Energy Spectra of Proton Production Cross Section Induced by 392 MeV Protons to Beryllium-9, terbium-159 and Gold-197, Kin Tadahiro, Hohara Sin-ya, Yamashita Yusuke, Imamura Minoru, Wakabayashi Genichiro, Uozumi Yusuke, Ikeda Nobuo, Matoba Masaru, Koori Norihiko, Proceedings of AESJ, 2004, 0, 45, 45,   2004 , http://ci.nii.ac.jp/naid/130004568259
    Summary:RCNPの東実験室において、392MeVの陽子ビームを<sup>9</sup>Be, <sup>159</sup>Tb, <sup>197</sup>Au等のターゲットに入射し、(p,p )二重微分断面積を測定した。実験値は量子分子動力学モデル(QMDモデル)と比較を行った。また、我々の研究室で開発した核内カスケードモデル(INCモデル)との比較も行った。
  • Survey and decontamination of radium-223 dichloride for alpha-particle radionuclide therapy in clinical facilities, M. Hosono, S. Hohara, M. Inagaki, H. Yamanishi, G. Wakabayashi, T. Matsuda, K. Sakaguchi, K. Hanaoka, T. Ito, EUROPEAN JOURNAL OF NUCLEAR MEDICINE AND MOLECULAR IMAGING, 43, S417, S417,   2016 10
  • Measurement and parameters of alpha-emitting radium-223 for radionuclide therapy in accordance with radiation protection standards, M. Hosono, S. Hohara, H. Yamanishi, M. Inagaki, G. Wakabayashi, T. Matsuda, K. Sakaguchi, K. Hanaoka, T. Itoh, EUROPEAN JOURNAL OF NUCLEAR MEDICINE AND MOLECULAR IMAGING, 41, S329, S329,   2014 10
  • Measurement and radiation control of alpha-emitting radium-223 in radionuclide therapy for prostate cancer with bone metastases, Makoto Hosono, Sin-ya Hohara, Hirokuni Yamanishi, Masayo Inagaki, Genichiro Wakabayashi, Kenta Sakaguchi, Kohei Hanaoka, Tetsuo Itoh, JOURNAL OF NUCLEAR MEDICINE, 55,   2014 05
  • [Thermoluminescence Slab Dosimeter]., Kiyomitsu Shinsho, Yusuke Koba, Satoshi Tamatsu, Noboru Sakurai, Genichiro Wakabayashi, Kazusige Fukuda, Igaku butsuri : Nihon Igaku Butsuri Gakkai kikanshi = Japanese journal of medical physics : an official journal of Japan Society of Medical Physics, 33, 3, 137, 144,   2013
    Summary:In 1953 F. Daniels et al. used the property of thermoluminescence in dosimetry for the first time. Since then, numerous TLD have been developed. 2D TLD was investigated for the first time in 1972 by P Broadhead. However, due to excessive fading, difficulties with handling and the time required for measurements, development stalled. At the current time, the majority of TLD are used in small scale, localized dosimetry with a wide dynamic range and personal dosimeters for exposure management. Urushiyama et. al. have taken advantage of the commoditization of CCD cameras in recent years--making large area, high resolution imaging easier--to introduce and develop a 2D TLD. It is expected that these developments will give rise to a new generation of applications for 2D TL dosimetry. This paper introduces the "TL Slab Dosimeter" developed jointly by Urushiyama et. al. and our team, its measurement system and several typical usage scenarios.
  • 100Mo(p, d)99Mo reaction at 21 MeV and direct reaction analysis of the low-lying continuum spectrum, S. Hirowatawari, A. Syafarudin, F. Aramaki, A. Nohtomi, G. Wakabayashi, Y. Uozumi, N. Ikeda, M. Matoba, Y. Aoki, K. Hirota, N. Okumura, T. Joh, Nuclear Physics A, 714, 1-2, 3, 20,   2003 02 10 , 10.1016/S0375-9474(02)01353-2
    Summary:The 100Mo(p, d)99 Mo reaction has been studied with 21 MeV polarized protons. Momentum spectra of the emitted deuterons corresponding to the excitation energy region up to 5.75 MeV in 99Mo have been measured. Theoretical analysis based on the standard distorted-wave Born approximation (DWBA) provides the lj-angular momentum transfers and spectroscopic factors of neutron hole states for 27 levels from the ground state up to EX = 2.921 MeV. The polarization data gave a more affirmative information in assigning the spins and parities. Spectrum regions from discrete levels to continuum were treated with a global analysis using the direct reaction model and continuous strength functions. The double differential cross section-energy spectra were reproduced fairly well using the DWBA-based cross sections and the asymmetrical Lorentzian form strength response function having energy-dependent spreading widths. © 2002 Elsevier Science B.V. All rights reserved.

Awards & Honors

  •   2016 04 , Japan Society of Medical Physics / Japanese Society of Radiological Technology, Doi Award