Collaborative Laboratories for Advanced Decommissioning Science; The University of Tokyo*
JAEA-Review 2020-024, 75 Pages, 2021/01
The Collaborative Laboratories for Advanced Decommissioning Science (CLADS), Japan Atomic Energy Agency (JAEA), had been conducting the Nuclear Energy Science & Technology and Human Resource Development Project (hereafter referred to "the Project") in FY2019. The Project aims to contribute to solving problems in the nuclear energy field represented by the decommissioning of the Fukushima Daiichi Nuclear Power Station, Tokyo Electric Power Company Holdings, Inc. (TEPCO). For this purpose, intelligence was collected from all over the world, and basic research and human resource development were promoted by closely integrating/collaborating knowledge and experiences in various fields beyond the barrier of conventional organizations and research fields. The sponsor of the Project was moved from the Ministry of Education, Culture, Sports, Science and Technology to JAEA since the newly adopted proposals in FY2018. On this occasion, JAEA constructed a new research system where JAEA-academia collaboration is reinforced and medium-to-long term research/development and human resource development contributing to the decommissioning are stably and consecutively implemented. Among the adopted proposals in FY2018, this report summarizes the research results of the "Development of Technology for Rapid Analysis of Strontium-90 with Low Isotopic Abundance using Laser Resonance Ionization" conducted in FY2019. In this study, we will develop a rapid analysis technique for strontium-90 using diode laser-based resonance ionization with elemental and isotopic selectivity. Strontium-90 is one of the major difficult-to-measure nuclides released into the environment due to the accident at TEPCO's Fukushima Daiichi Nuclear Power Station. Our method is particularly intended for real samples which contain high concentrations of strontium stable isotopes such as marine samples.
Shibahara, Yuji*; Nakamura, Shoji; Uehara, Akihiro*; Fujii, Toshiyuki*; Fukutani, Satoshi*; Kimura, Atsushi; Iwamoto, Osamu
Journal of Radioanalytical and Nuclear Chemistry, 325(1), p.155 - 165, 2020/07
The measurements of isotopic ratios of Cs samples by thermal ionization mass spectrometry were performed for the analysis of their samples used to evaluate nuclear data obtained for Cs. To obtain a high intensity and stable ion beam, the effects of additive agents on the ionization of Cs were examined. The effect of silicotungstic acid on the ionization of Cs was the largest among the additive agents studied in the present study, while the silicotungstic acid also showed the largest isobaric interference of polyatomic ions. It was demonstrated that as small as 210 g of a Cs sample was sufficient to achieve the analytical precision required to measure the Cs/Cs ratio in the case where an additive agent of TaO/glucose was employed. After examining of the analytical conditions, such as the interference effect due to Ba, the measurements of the isotopic ratios of two Cs samples used in our study using TIMS were conducted, and it was discussed how much the ratios contributed to evaluation of the neutron capture cross-section of Cs.
Collaborative Laboratories for Advanced Decommissioning Science; The University of Tokyo*
JAEA-Review 2019-027, 70 Pages, 2020/01
JAEA/CLADS, had been conducting the Center of World Intelligence Project for Nuclear Science/Technology and Human Resource Development (hereafter referred to "the Project") in FY2018. The Project aims to contribute to solving problems in nuclear energy field represented by the decommissioning of the Fukushima Daiichi Nuclear Power Station, Tokyo Electric Power Company Holdings, Inc. For this purpose, intelligence was collected from all over the world, and basic research and human resource development were promoted by closely integrating/collaborating knowledge and experiences in various fields beyond the barrier of conventional organizations and research fields. The sponsor of the Project was moved from the Ministry of Education, Culture, Sports, Science and Technology to JAEA since the newly adopted proposals in FY2018. On this occasion, JAEA constructed a new research system where JAEA-academia collaboration is reinforced and medium-to-long term research/development and human resource development contributing to the decommissioning are stably and consecutively implemented. Among the adopted proposals in FY2018, this report summarizes the research results of the "Development of Technology for Rapid Analysis of Strontium-90 with Low Isotopic Abundance Using Laser Resonance Ionization". In this study, we will develop a rapid analysis technique for strontium-90 using diode laser-based resonance ionization with elemental and isotopic selectivity. Strontium-90 is one of the major difficult-to-measure nuclides released into the environment due to the accident at Tokyo Electric Power Company (TEPCO)'s Fukushima Daiichi Nuclear Power Station. Our method is particularly intended for real samples which contain high concentrations of strontium stable isotopes such as marine samples.
Cubiss, J. G.*; Andreyev, A. N.; Barzakh, A. E.*; Andel, B.*; Antalic, S.*; Cocolios, T. E.*; Day Goodacre, T.*; Fedorov, D. V.*; Fedosseev, V. N.*; Ferrer, R.*; et al.
Physical Review C, 99(6), p.064317_1 - 064317_6, 2019/06
An decay of At was studied at the CERN-ISOLDE facility using a laser-ionization technique. Coincidence - data were collected for the first time and a more precise half-life value of T = 1.27(6) s was measured. A new -decay scheme was deduced based on the fine-structure of the decay. The results lead to a preferred spin and parity assignment of J = (3) for the ground state of At; however, J = (2) cannot be fully excluded.
Tsai, P.-E.; Iwamoto, Yosuke; Hagiwara, Masayuki*; Sato, Tatsuhiko; Ogawa, Tatsuhiko; Satoh, Daiki; Abe, Shinichiro; Ito, Masatoshi*; Watabe, Hiroshi*
Proceedings of 2017 IEEE Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC 2017) (Internet), 3 Pages, 2018/11
The energy spectra of primary knock-on atoms (PKAs) are essential for radiation damage assessment in design of accelerator facilities. However up to date the experimental data are still limited, due to the poor mass resolution and the high measurement threshold energies in the conventional setup of nuclear physics experiments using solid state detectors, which are typically above a few MeV/nucleon. In this study, a novel detection system consisting of two time detectors and one dE-E energy detector is proposed and being constructed to measure the PKA spectra. The system and detector design was based on Monte Carlo simulations by using the PHITS code. The PHITS simulations show that the system is able to distinguish the PKA isotopes above 0.2-0.3 MeV/nucleon for A=2030 amu; the PKA mass identification thresholds decrease to 0.1 MeV/nucleon for PKAs lighter than 20 amu. The detection system will be tested in the summer of 2017, and the test results will be presented at the conference.
Baba, Yuji; Shimoyama, Iwao
e-Journal of Surface Science and Nanotechnology (Internet), 16, p.53 - 59, 2018/03
Surface ionization for cesium chloride and Cs-adsorbed soil has been investigated. For cesium chloride, neutral cesium was desorbed around 645C which is close to the melting point of cesium. While Cs ion was desorbed from 400C. The ratio of desorbed ions and neutrals (Cs/Cs) has a maximum around 410 C. Temperature dependence of Cs/Cs was analyzed using Saha-Langmuir equation, As a result, it was found that the temperature maximum is due to the changes of the surface work function induced by the phase transition of CsCl.
Esaka, Fumitaka; Suzuki, Daisuke; Yomogida, Takumi; Magara, Masaaki
Analytical Methods, 8(7), p.1543 - 1548, 2016/02
The isotope ratio analysis of individual uranium particles in environmental samples taken at nuclear facilities is important to clarify their origins for nuclear safeguards. In the present study, automated particle screening was used to select uranium particles prior to precise isotope ratio analysis by thermal ionization mass spectrometry (TIMS). As a result, molecular ion interferences on the uranium mass region were able to be almost completely avoided in the analysis of real inspection samples using APM-TIMS. Therefore, the performance of APM-TIMS was sufficient for obtaining isotope ratio data of individual particles without molecular ion interferences.
Herv du Penhoat, M.-A.*; Kamol Ghose, K.*; Gaigeot, M.-P.*; Vuilleumier, R.*; Fujii, Kentaro; Yokoya, Akinari; Politis, M.-F.*
Physical Chemistry Chemical Physics, 17(48), p.32375 - 32383, 2015/12
Tabata, Tatsuo*; Shirai, Toshizo*; Sataka, Masao; Kubo, Hirotaka
Atomic Data and Nuclear Data Tables, 92(3), p.375 - 406, 2006/05
no abstracts in English
Miyabe, Masabumi; Oba, Masaki; Kato, Masaaki; Wakaida, Ikuo; Watanabe, Kazuo
Journal of Nuclear Science and Technology, 43(4), p.305 - 310, 2006/04
We are developing an resonance ionization spectrometric apparatus aiming at an analysis of a radioactive isotope of calcium (Ca) in nuclear waste materials. The developed system consists of the reference laser whose frequency was locked on a Doppler-free absorption line of 85Rb and the computer-controlled fringe offset lock system which transfer frequency stability of the reference laser to slave lasers for Ca excitation. With heterodyne spectroscopy and laser induced fluorescence spectroscopy of Ca, it was confirmed that the developed apparatus was suitable for resonance ionization spectrometric analysis.
Fukuda, Yuji; Kishimoto, Yasuaki; Masaki, Tomohiro*; Yamakawa, Koichi
Physical Review A, 73(3), p.031201_1 - 031201_4, 2006/03
An ultrashort, intense laser-cluster interaction and a resultant structure formation are investigated in detail by employing a particle code including relaxation and ionization processes. In addition to a laser-induced polarization field, we have found that an ambipolar radial electric field and an internal/external sheath field play a key role in a disassembling dynamics of the cluster. Electrons and ions show a complex behavior leading to a prominent dip structure in electron energy distribution and a double structure in ion density and energy distributions for higher charge states.
Akahane, Yutaka; Ma, J.; Fukuda, Yuji; Aoyama, Makoto; Kiriyama, Hiromitsu; Inoue, Norihiro*; Tsuji, Koichi*; Nakai, Yoshiki*; Yamamoto, Yoichi*; Sheldakova, J. V.*; et al.
Japanese Journal of Applied Physics, Part 1, 44(8), p.6087 - 6089, 2005/08
An improvement of laser-focused peak intensity has been achieved in a JAERI 100 TW Ti:sapphire chirped-pulse amplifier chain with a feedback-controlled adaptive optics system. Measurements of optical parameters of the laser pulse and an experimental tunneling ionization ratio of a rare gas atom with laser energy scaling have practically confirmed an ultrarelativistic intensity of over 10 W/cm operating at a 10 Hz repetition rate.
JAERI-Research 2004-017, 29 Pages, 2004/11
Based on the Green's reciprocation theorem, the charge distributions on the electrode of ionization counters induced by a point charge that exist between the electrodes have been derived in a closed form. The shape of the electrodes were assumed to be parallel plates or cylindrical. In the case of parallel plate electrodes, the distribution can be expressed by an integral of Bessel function of zero order. On the other hands, in the case of cylindrical electrodes, the distribution can be expressed by an integral of modified Bessel function of zero order. These expressions will be useful to calculate current signals of counters because the current signal can be obtained by differentiating the charge distribution.
Miyabe, Masabumi; Kato, Masaaki; Oba, Masaki; Wakaida, Ikuo; Watanabe, Kazuo
JAERI-Tech 2004-065, 19 Pages, 2004/10
In nuclear waste materials there are various radionuclides to which standard analytical techniques are difficult to be applied. We are developing an analytical technique where such nuclides are ionized and mass-analyzed using diode laser based multi-step RIMS technique. The diode laser, however, has one drawback, i.e. its oscillation wavelength is readily drifted by acoustic, electric and optical noise, and thus the laser without frequency stabilization is not suitable for the analysis. In this study, we have developed (1) the diode laser whose frequency is stabilized to an intense absorption line of Rb by Zeeman effect and (2) the stabilization system where diode lasers for 3-step ionization of Ca are locked to the Rb-stabilized laser using a Fabry-perot interferometer. Additionally, to evaluate overall frequency stability of the stabilization system, fluctuations in the photoion and fluorescence signals arising from 3-step RIMS of Ca were simultaneously observed.
Miyabe, Masabumi; Oda, Koichi*; Oba, Masaki; Kato, Masaaki; Wakaida, Ikuo; Watanabe, Kazuo
JAERI-Tech 2004-064, 33 Pages, 2004/10
In nuclear waste materials there are various radionuclides to which standard analytical techniques are difficult to be applied. We are developing an analytical technique where such nuclides are analyzed using multi-step resonance ionization mass spectrometry. In this study, we have developed an external cavity diode laser applicable to the analysis. The wavelength and output power dependence on injection current and temperature were investigated for various types of laser diodes. Based on the data, we have obtained a suitable condition to operate the ECDL in stable single-mode oscillation, so that a continuous scanning range of about 100 GHz was realized. Additionaly, to evaluate the bandwidth of the developed ECDL, we have performed Doppler-free spectroscopy. The reasonable agreement of the measured isotope shift and HFS splitting with the reported values demonstrated that the developed ECDL is applicable to a precise laser spectroscopy as well as a laser trace analysis.
Fukuda, Mitsuhiro; Ito, Hisayoshi; Oshima, Takeshi; Saido, Masahiro; Tanaka, Atsushi
Charged Particle and Photon Interactions with Matter, p.813 - 859, 2003/11
An ion beam has been widely applied to a variety of research fields of materials, space, and bio-sciences. Notable results, which were hard to obtain in applications of a ray and an electron beam, have been produced by the ion beam application. Ion beams interacting with matter have such superior properties as highly localized ionization and excitation, production of secondary particles, implantation of different atoms, and nuclear transmutation of constituent atoms. Skillful utilization of the ion beam properties makes remarkable progress in creation of new materials and precise investigation of matters. The ion beam irradiation research facility, TIARA, was established in 1993 at JAERI for extensive applications of ion beams. An accelerator complex provides light to heavy ion beams with a broad energy range from keV to GeV. Various ion beam technologies pioneering the ion beam applications have been developed at TIARA. In this paper, new applications of accelerated ion beams to material, space, and biological science and engineering carried out mainly at TIARA are reviewed.
Katayama, Atsushi; Furukawa, Katsutoshi; Watanabe, Kazuo
Bunseki Kagaku, 52(6), p.461 - 467, 2003/06
An imaging ion detection system was introduced to a time-of-flight mass spectrometer (TOFMS) in order to increase dynamic range in the isotope ratio measurements. The new detection system utilizes a position sensitive micro channel plate (MCP) with a phosphor plate and a CCD camera which records light spots on the MCP. Mass discriminated ion beams produced by laser resonance ionization were swept on the surface of MCP by a time-depended electric field located in front of the MCP. The resulting light spots were recorded as images by CCD camera. A mass spectrum was obtained from the images. The present method was applied to the isotope analysis of calcium. A dynamic range of more than 5 orders of magnitude was achieved.
Koizumi, Mitsuo; Osa, Akihiko; Oshima, Masumi; Sekine, Toshiaki; Wakui, Takashi*; Jin, W.*; Katsuragawa, H.*; Miyatake, Hiroari*; Ishida, Yoshihisa*
Nuclear Instruments and Methods in Physics Research B, 204(1-4), p.359 - 362, 2003/05
no abstracts in English
Tobita, Kenji; Kusama, Yoshinori; Shinohara, Koji; Nishitani, Takeo; Kimura, Haruyuki; Kramer, G. J.*; Nemoto, Masahiro*; Kondoh, Takashi; Oikawa, Toshihiro; Morioka, Atsuhiko; et al.
Fusion Science and Technology (JT-60 Special Issue), 42(2-3), p.315 - 326, 2002/09
Energetic particle experiments in JT-60U are summarized, mainly covering ripple loss and Alfven eigenmodes (AE modes). Significant loss was observed for 85 keV NBI ions and fusion-produced tritons increased when toroidal field ripple at the plasma surface, especially in reversed shear plasma. Measurement of hot spots on the first wall due to ripple loss confirmed agreement with code predictions, validating the modeling incorporated in an orbit-following Monte Carlo code. A variety of AE modes were destabilized in ICRF minority heating and negative-ion-based NBI (N-NBI) heating. Most of the observed modes are gap modes identified to be TAE, EAE and NAE. Interesting finding is pulsating modes accompanying frequency sweep, which were destabilized by N-NBI and sometimes induced a beam ion loss of up to 25%. Also presented are energetic particle issues in auxiliary heating with ICRF and N-NBI.
Ishikawa, Norito; Iwase, Akihiro; Chimi, Yasuhiro; Michikami, Osamu*; Wakana, Hironori*; Hashimoto, Takeo*; Kambara, Tadashi*; Mller, C.*; Neumann, R.*
Nuclear Instruments and Methods in Physics Research B, 193(1-4), p.278 - 282, 2002/06
Swift heavy ions with wide energy range of 80MeV-3.84GeV have been irradiated to EuBaCuO oxide superconductors, and the lattice parameter change due to elecronic excitation has been measured. In the high ion-velocity region, the change in lattice parameter per unit fluence varies as the 4th power of the electronic stopping power. However, in the low-velocity region, the deviation from the 4th power dependence is observed. The results are analyzed by using the primary ionization rate, and it is found that the results support that the Coulomb explosion triggers the atomic displacements.