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Kofu, Maiko; Kawamura, Seiko; Murai, Naoki; Ishii, Rieko*; Hirai, Daigoro*; Arima, Hiroshi*; Funakoshi, Kenichi*
Physical Review Research (Internet), 6(1), p.013006_1 - 013006_9, 2024/01
Haraga, Tomoko; Saito, Shingo*
Bunseki Kagaku, 70(12), p.671 - 679, 2021/12
We developed highly sensitive capillary electrophoresis-laser-induced fluorescence detection methods for lanthanide (Ln) and actinide (An) ions with small sample volume and low emission of waste, by which the radiation risk can be minimized. Specifically, determination of Nd ion in spent nuclear fuel, effective separation between Am and Cm ion, and specific detection of UO in real radioactive samples were achieved by molecular design of fluorescence probes composed of an aminocarboxylate chelating moiety, a fluorophore and a spacer, and unique separation mode based on dynamic ternary complexation. We found that there are appropriate combination of probe and ternary complexation for detection and separation of each Ln and An ions. For example, acyclic and macrocyclic hexadentate is suitable for Ln, Am and Cm, and planer tetradentate with electron system is specific for UO, with ppt-sub ppt level detection.
Metoki, Naoto
Kotai Butsuri, 55(7), p.285 - 296, 2020/07
Electron states are the main theme of "solid-state physics", which is essential for microscopic understanding of multipoles and superconductivity, etc. Rare earths (4) and actinides (5) provide variety of interesting states realized with competing interactions between the increasing number of electrons. Since crystal field splitting of many-body electron system is smaller than the bandwidth, (1) high resolution experiments are needed, (2) essentially no clear spectrum with well defined peaks is expected in itinerant Ce and U compounds, and (3) Np and Pu is strictly regulated. Therefore, systematic research on magnetic excitations by neutron scattering experiments of localized compounds and rare earth iso-structural reference is useful. We describe the electron states of heavy electron compounds NpPdAl and actinide and rare earth based iso-structural family.
Ikeura, Hiromi*; Sekiguchi, Tetsuhiro
Japanese Journal of Applied Physics, 58(SI), p.SIIC04_1 - SIIC04_4, 2019/08
Times Cited Count:0 Percentile:0(Physics, Applied)The electronic structure of the unoccupied conduction band of polycrystalline chloroaluminum phthalocyanine was investigated by X-ray absorption spectroscopy (XAS) near the Cl K-edge. XAS spectra were recorded in total electron yield (TEY) and partial Auger electron yield (AEY) modes. Partial AEY spectra were measured using normal and spectator Cl KLL Auger yields as a function of photon energy. Although the TEY spectrum showed a broad shape; that was difficult to deconvolute curve fitting, the normal and spectator AEY spectra clearly showed that *(Cl-Al) transition splits into two competitive peaks attributed to the core excitons (localized with a core hole) and conduction band (delocalized without a core hole). The existence of a band-like peak in the Cl K-edge XAS is evidence that the Cl axial ligand participates in forming the conduction band. Thus, band-like electron transport is expected to occur in the oligomer-like (-Al-Cl-Al-) site.
Kurosaki, Yuzuru*; Yokoyama, Keiichi
Universe (Internet), 5(5), p.109_1 - 109_15, 2019/05
Times Cited Count:0 Percentile:0.01(Astronomy & Astrophysics)Regarding rovibrational transitions of diatomic alkali haride molecules, optimal waveform of laser electric field was calculated on the basis of the optimal control theory. In this study, we implemented the polarizability term into the Hamiltonian, which defines the field-molecule interaction. As a result, we obtained waveforms causing both one- and two-photon processes in a relatively high electric field regime, while waveforms causing only one-photon process was observed in a weak filed regime as well as the previous study. These results imply that the effect of two-photon process is successfully taken into account in the optimal control theory calculation. Now we can expect more reliable calculation even for strong laser field.
Takahashi, Fumiaki
Genshiryoku No Ima To Ashita, p.106 - 109, 2019/03
The Atomic Energy Society of Japan has planned to publish a document for public, entitled "Current and tomorrow of atomic energy, -Experiences from the accident at the Tokyo Electronic Power Company Fukushima Dai-ichi NPPs-". The documents give us basics and usages of radiations, in addition to nuclear power plants and the accident at TEPCO Fukushima Dai-ichi NPPs. This manuscript explains interactions and penetrations in material for -rays, -rays, -rays and neutrons. In addition, exposure characteristics that is determined by properties of radiations are expressed here. This manuscript also explains characteristics in internal exposure and countermeasures of radiation protection following the TEPCO accident for Iodine-131 and Cesium-137.
Tomiyasu, Keisuke*; Ito, Naoko*; Okazaki, Ryuji*; Takahashi, Yuki*; Onodera, Mitsugi*; Iwasa, Kazuaki*; Nojima, Tsutomu*; Aoyama, Takuya*; Ogushi, Kenya*; Ishikawa, Yoshihisa*; et al.
Advanced Quantum Technologies (Internet), 1(3), p.1800057_1 - 1800057_7, 2018/12
Spin-state transition, also known as spin crossover, plays a key role in diverse systems. In theory, the boundary range between the low- and high-spin states is expected to enrich the transition and give rise to unusual physical states. However, no compound that realizes a nearly degenerate critical range as the ground state without requiring special external conditions has yet been experimentally identified. This study reports that the Sc substitution in LaCoO3 destabilizes its nonmagnetic low-spin state and generates an anomalous paramagnetic state accompanied by the enhancement of transport gap and magneto-lattice-expansion as well as the contraction of Co-O distance with the increase of electron site transfer. These phenomena are not well described by the mixture of conventional low- and high-spin states, but by their quantum superposition occurring on the verge of a spin-state transition.
Ikeuchi, Kazuhiko*; Nakajima, Kenji; Kawamura, Seiko; Kajimoto, Ryoichi; Wakimoto, Shuichi; Suzuki, Kensuke*; Fujita, Masaki*
AIP Advances (Internet), 8(10), p.101318_1 - 101318_5, 2018/10
Times Cited Count:0 Percentile:0(Nanoscience & Nanotechnology)By means of inelastic neutron scattering, we measured magnetic excitations in a sizable single crystal of LaSrCuAlO, which is an Al-substituted system of the heavily hole-doped cuprate system LaSrCuO with an effective concentration of holes of = 0.25.
Sako, Hiroyuki
JPS Conference Proceedings (Internet), 17, p.063004_1 - 063004_2, 2017/07
N*, baryon excited states have been studied for a long time, but many of high mass states have not been found yet. Recent theoretical studies clarified that channels have large contributions to these high mass states. Therefore we have proposed an experiment at J-PARC (E45) to measure reactions. In this presentation, we will show the overview of the experiment and current status of detector developments.
Nishinaka, Ichiro; Yokoyama, Akihiko*; Washiyama, Koshin*; Maeda, Eita*; Watanabe, Shigeki; Hashimoto, Kazuyuki; Ishioka, Noriko; Makii, Hiroyuki; Toyoshima, Atsushi; Yamada, Norihiro*; et al.
Journal of Radioanalytical and Nuclear Chemistry, 304(3), p.1077 - 1083, 2015/06
Times Cited Count:9 Percentile:60.64(Chemistry, Analytical)Production cross sections of astatine isotopes At in the 29-57 MeV Li induced reaction with Pb target have been measured by - and -ray spectrometry. Excitation functions of production cross sections have been compared with a statistical model calculation to study the reaction mechanism of Li + Pb. Considerably small experimental cross sections of At and At compared with the calculation were clearly observed at incident energies higher than 44 MeV, indicating that the effects of breakup reaction play a role. A chemical separation of astatine from an irradiated lead target has been studied with a dry-distillation method. A complementary way to produce astatine isotopes has been developed.
Kai, Takeshi; Yokoya, Akinari; Ukai, Masatoshi*; Watanabe, Ritsuko
Radiation Physics and Chemistry, 108, p.13 - 17, 2015/03
Times Cited Count:25 Percentile:89.99(Chemistry, Physical)Role of secondary electrons on DNA damage have not been understood sufficiently because there still exists a lack of cross section of rotational and phonon excitation in the liquid phase for precise simulation of the electron behavior. We calculated cross sections, stopping powers, and energy loss rates for the excitations in liquid water. The values for rotation are less by three orders of magnitude than those in the gas phase, while the values for phonon are close to those reported for amorphous ice. Thermalization process has so far been estimated from an assumption that the energy loss rates do not depend strongly on the energy below 1 eV. However, we found that the energy loss rates depend significantly on the energy. This fact indicates that the thermalization time will be longer than the previously estimated time, and we predict that thermalization process strongly involve in subsequent hydrated and chemical processes. The data set provide here is expected to useful to make the role of the secondary electrons on DNA damage much clear.
Itakura, Ryuji
Reza Kenkyu, 43(3), p.136 - 137, 2015/03
Recently, technique of pulsed electron beam generation combined with ultrafast laser technology has been developed for realization of time-resolved measurements. A variety of methods such as an electron gun with a photo-cathode and an optical gating of a CW electron beam are proposed and demonstrated. We will compiles topical papers on frontier of pulsed electron beam for research on photoexcited dynamics in one volume of "The Review of Laser Engineering". This paper is a preface for describing the aim and contents of this special volume.
Sugai, Hiroyuki; Matsunami, Noriaki*; Fukuoka, Osamu*; Sataka, Masao; Kato, Teruo; Okayasu, Satoru; Shimura, Tetsuo*; Tazawa, Masato*
Nuclear Instruments and Methods in Physics Research B, 250(1-2), p.291 - 294, 2006/09
Times Cited Count:15 Percentile:70.56(Instruments & Instrumentation)We have investigated the effects on electrical properties of Al-doped ZnO (AZO) semiconductor films induced by high-energy heavy ion. The AZO films with c-axis on SiO glass substrate were prepared by a RF-sputter-deposition method at 400 C. Rutherford backscattering spectroscopy shows that the Al/Zn composition and the film thickness are 4 % and 0.3 m. We find that the conductivity monotonically increases from 1.510 to 810 S/cm with increasing the fluence up to 410/cm, as already been observed for 100 keV Ne irradiation. The fluence of 100 keV Ne at which the conductivity takes its maximum is 310/cm (7 dpa). The dpa of 100 MeV Xe at 410/cm is estimated as 0.008. Hence, the conductivity increase by 100 MeV Xe ion is ascribed to the electronic excitation effects.
Ishikawa, Norito; Yamamoto, Shunya; Chimi, Yasuhiro
Nuclear Instruments and Methods in Physics Research B, 250(1-2), p.250 - 253, 2006/09
Times Cited Count:42 Percentile:92.74(Instruments & Instrumentation)Electronic excitation effects on TiO thin films with anatase structure irradiated with 230MeV Xe ions have been studied by means of X-ray diffraction method. X-ray diffraction intensity shows exponential decrease as a function of ion-fluence, indicating that tracks having about 10nm diameter are introduced by the irradiation. Rutile structured TiO was also irradiated and exhibited different damage behavior from that of anatase one. We demonstrated that X-ray diffraction meathod is one of the powerful tool to investigate track structure.
Fukuoka, Osamu*; Matsunami, Noriaki*; Tazawa, Masato*; Shimura, Tetsuo*; Sataka, Masao; Sugai, Hiroyuki; Okayasu, Satoru
Nuclear Instruments and Methods in Physics Research B, 250(1-2), p.295 - 299, 2006/09
Times Cited Count:24 Percentile:83(Instruments & Instrumentation)We have investigated the effects on electrical and optical properties of Al-doped ZnO (AZO) semiconductor films induced by high-energy heavy ion. The AZO films with c-axis on SiO glass substrate were prepared by a RF-sputter-deposition method at 400 C. Rutherford backscattering spectroscopy shows that the Al/Zn composition and the film thickness are 4 % and 0.3 m. No appreciable change was observed in optical transparency. We find that the conductivity monotonically increases from 1.510 to 810 S/cm with increasing the fluence up to 410/cm, as already been observed for 100 keV Ne irradiation. The fluence of 100 keV Ne at which the conductivity takes its maximum is 310/cm (7 dpa). The dpa of 100 MeV Xe at 410/cm is estimated as 0.008. Hence, the conductivity increase by 100 MeV Xe ion is ascribed to the electronic excitation effects.
Kaneko, Koji; Metoki, Naoto; Bernhoeft, N.*; Matsuda, Tatsuma; Haga, Yoshinori; Yasuda, Takashi*; Takeuchi, Tetsuya*; Settai, Rikio*; Onuki, Yoshichika
Journal of the Physical Society of Japan, 75(Suppl.), p.177 - 179, 2006/08
no abstracts in English
Chimi, Yasuhiro; Iwase, Akihiro*; Ishikawa, Norito; Kobiyama, Mamoru*; Inami, Takashi*; Kambara, Tadashi*; Okuda, Shigeo*
Nuclear Instruments and Methods in Physics Research B, 245(1), p.171 - 175, 2006/04
Times Cited Count:16 Percentile:72.85(Instruments & Instrumentation)We have studied effects of irradiation with energetic particles on defect accumulation in nanocrystalline gold (nano-Au). The specimens of nano-Au foil (3-5 m thickness) with various grain sizes (23-156 nm) are prepared by the gas deposition method and subsequent thermal annealings. Irradiations of the specimens with 60-MeV C ions, 3.54-GeV Xe ions or 2.0-MeV electrons are performed at low temperature. The defect accumulation behavior is observed by measuring the electrical resistivity change during irradiation. Through an analysis of defect accumulation behavior, cross-sections for defect production, , and annihilation, , in nano-Au increase monotonically as the grain size decreases. These results are considered to be caused by the existence of a large volume fraction of the regions near grain boundaries in nano-Au where the threshold energy for atomic displacements, E, becomes lower than in polycrystalline gold. The possibility of electronic excitation effects in nano-Au is also discussed.
Fukuzumi, Masafumi*; Chimi, Yasuhiro; Ishikawa, Norito; Suzuki, Motohiro*; Takagaki, Masafumi*; Mizuki, Junichiro; Ono, Fumihisa*; Neumann, R.*; Iwase, Akihiro*
Nuclear Instruments and Methods in Physics Research B, 245(1), p.161 - 165, 2006/04
Times Cited Count:17 Percentile:74.61(Instruments & Instrumentation)We have performed swift heavy ion irradiations in Fe-50at.%Rh alloys at room temperature. Before and after the irradiations, the magnetic properties and the lattice structure are measured using Superconducting QUantum Interference Device (SQUID) and X-Ray Diffractometer (XRD), respectively. We have also performed X-ray Magnetic Circular Dichroism (XMCD) measurement near the Fe K-edge at the synchrotron radiation facility, SPring-8, to examine the irradiation-induced ferromagnetic state near the specimen surface. We have found that the swift heavy ion irradiations induce the ferromagnetic state in Fe-50at.%Rh alloy below the antiferromagnetism-ferromagnetism transition temperature of the unirradiated alloy and the lattice expasion by 0.3%. For the specimens irradiated with swift heavy ions, we observe the XMCD spectra correponding to ferromagnetisim, which depend on the mass of irradiating ions and/or irradiation fluence. Effects of energy loss through electronic excitation and elastic collisions on lattice and magnetic structures of Fe-Rh alloy are discussed.
Yamamoto, Tomokazu*; Shimada, Mikio*; Yasuda, Kazuhiro*; Matsumura, Sho*; Chimi, Yasuhiro; Ishikawa, Norito
Nuclear Instruments and Methods in Physics Research B, 245(1), p.235 - 238, 2006/04
Times Cited Count:13 Percentile:65.83(Instruments & Instrumentation)We have investigated the microstructure change and atomic disordering process in magnesium aluminate spinel, MgO AlO with =1.1 and 2.4, irradiated with swift heavy ions of 200-MeV Xe and 350-MeV Au. Transmission electron microscopy techniques of bright-field (BF) and high-resolution (HR) imaging, as well as high angular resolution electron channeling X-ray spectroscopy (HARECXS) are employed in quantitative analysis of irradiation-induced structural change. Ion tracks show columnar dark contrast of 4-7 nm in diameter at the incident surface in BF images. Strong strain contrast often arises among plural ion tracks formed closely. Clear lattice fringes are observed in HR images even inside the ion tracks. It indicates that the spinel crystals are not amorphized but partially disordered along the ion tracks. Quantitative HARECXS analysis shows that cation disordering progresses with ion fluence. It is revealed that the disordered regions are extended over 122 nm in diameter along the ion tracks.
Akagi, Hiroshi; Fukazawa, Hiroshi; Yokoyama, Keiichi; Yokoyama, Atsushi
Journal of Chemical Physics, 123(18), p.184305_1 - 184305_7, 2005/11
Times Cited Count:21 Percentile:57.25(Chemistry, Physical)Vibrationally excited HOD in the fourth overtone state of the OD-stretching mode (5) has been photodissociated by ultraviolet photolysis at ca. 243.1 nm. Branching ratio between the OH- and OD-bond dissociation channels has been determined by detecting the H and D atoms. The OD-bond dissociation is the dominant channel, with the yield of H atom generated by the photolysis being below the detection limit.