60 results on '"Atsushi Hatakeyama"'
Search Results
2. Optical and spin-selective time-of-flight measurement of light-induced desorption of Rb from Fe $$_3$$ 3 O $$_4$$ 4 surfaces
- Author
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Kanta Asakawa, Naoki Tanabe, Taizo Kawauchi, Katsuyuki Fukutani, and Atsushi Hatakeyama
- Subjects
Medicine ,Science - Abstract
Abstract Light-induced desorption of Rb atoms from a ferrimagnetic Fe $$_3$$ 3 O $$_4$$ 4 (001) surface was studied using a spin-selective optical method, which provides information on the spin polarization, velocity distribution, and amount of the desorbed atoms. The results showed that the intensity of the desorption of Rb from Fe $$_3$$ 3 O $$_4$$ 4 (001) induced by ultraviolet (UV) light irradiation was smaller than the detection limit at coverages lower than the threshold coverage at which the desorption rate began to increase. Moreover, the average magnetic quantum number of the desorbed atoms was smaller than that of electrons at the Fermi level of the Fe $$_3$$ 3 O $$_4$$ 4 (001) surface. These indicate that the light-induced desorption of Rb from an Fe $$_3$$ 3 O $$_4$$ 4 (001) surface occurs only in the high-coverage region in which the desorbing atoms are not in contact with the Fe $$_3$$ 3 O $$_4$$ 4 surface, and that the desorption does not involve spin transfer.
- Published
- 2023
- Full Text
- View/download PDF
3. Detection of radiation torque exerted on an alkali-metal vapor cell
- Author
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Atsushi Hatakeyama, Runa Yasuda, Yutaka Goto, Natsumi Chikakiyo, Takahiro Kuroda, and Yugo Nagata
- Subjects
Physics ,QC1-999 - Abstract
We have developed a torsion balance to detect the rotation of a cell containing spin-polarized gaseous atoms to study angular momentum transfer from gaseous atoms to solid. A cesium vapor cell was hung from a thin wire in a vacuum chamber, and irradiated from the bottom with circularly polarized light tuned to the D2 transition to polarize cesium atoms in the cell. By varying the light helicity at the resonance frequency of the torsion balance, we induced forced rotational oscillation of the cell and detected radiation torque exerted on the cesium vapor cell through the cesium atoms inside. The torque was particularly large when both hyperfine levels of cesium atoms were optically pumped with application of a longitudinal magnetic field. Further detailed study will provide new insights into spin-transfer processes at the gas-solid interface.
- Published
- 2019
- Full Text
- View/download PDF
4. Optical and magnetic properties of a transparent garnet film for atomic physics experiments
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Mari Saito, Ryoichi Tajima, Ryota Kiyosawa, Yugo Nagata, Hiroyuki Shimada, Takayuki Ishibashi, and Atsushi Hatakeyama
- Subjects
Physics ,QC1-999 - Abstract
We investigated the optical and magnetic properties of a transparent magnetic garnet with a particular focus on its applications to atomic physics experiments. The garnet film used in this study was a magnetically soft material that was originally designed for a Faraday rotator at optical communication wavelengths in the near infrared region. The film had a thickness of 2.1 μm and a small optical loss at a wavelength of λ=780 nm resonant with Rb atoms. The Faraday effect was also small and, thus, barely affected the polarization of light at λ=780 nm. In contrast, large Faraday rotation angles at shorter wavelengths enabled us to visualize magnetic domains, which were perpendicularly magnetized in alternate directions with a period of 3.6 μm. We confirmed the generation of an evanescent wave on the garnet film, which can be used for the optical observation and manipulation of atoms on the surface of the film. Finally, we demonstrated a magnetic mirror for laser-cooled Rb atoms using the garnet film.
- Published
- 2016
- Full Text
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5. Light-induced Desorption of Alkali-metal Atoms as a Source of Laser-cooled Atoms
- Author
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Atsushi Hatakeyama
- Subjects
Materials science ,law ,Desorption ,Light induced ,Alkali metal ,Photochemistry ,Laser ,law.invention - Published
- 2020
6. Magnetism of Al$_x$Fe$_{2-x}$GeO$_5$ with Andalusite Structure
- Author
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Kazuo Kakimoto, Saki Takada, Hiroto Ohta, Yuya Haraguchi, Masato Hagihala, Shuki Torii, Takashi Kamiyama, Hiroyuki Mitamura, Masashi Tokunaga, Atsushi Hatakeyama, and Hiroko Aruga Katori
- Subjects
Condensed Matter - Materials Science ,Condensed Matter - Strongly Correlated Electrons ,Strongly Correlated Electrons (cond-mat.str-el) ,General Physics and Astronomy ,Materials Science (cond-mat.mtrl-sci) ,FOS: Physical sciences - Abstract
The magnetism of Al$_x$Fe$_{2-x}$GeO$_5$ from $x$ = 0.09 to $x$ = 0.91 with andalusite structure was examined. The magnetic properties of Al$_x$Fe$_{2-x}$GeO$_5$ at low temperatures were found to be weak ferromagnetic-like state for $x$ $$ 0.3. The small spontaneous magnetization that appears in the weak ferromagnetic-like phase would be due to the presence of Dzyaloshinsky-Moriya interaction or to the difference in the magnitude of the magnetic moment of Fe$^{3+}$ in the octahedral and trigonal bipyramidal sites. The appearance of the spin-glass phase indicates that the dilution of Fe ions by Al ions in Al$_x$Fe$_{2-x}$GeO$_5$ causes the competition between ferromagnetic and antiferromagnetic interactions. The $x$ dependence of the site occupancy of Fe ions suggests that Fe$_2$GeO$_5$ with andalusite structure cannot be synthesized., Comment: 19 pages, 14 figure
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- 2022
- Full Text
- View/download PDF
7. Output current ripple reduction of LED driver using ceramic‐capacitor‐input circuit and buck‐boost converter
- Author
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Mitsuhiro Kadota, Atsushi Hatakeyama, Keiji Wada, and Hiroyuki Shoji
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Reduction (complexity) ,business.industry ,Interface circuits ,Computer science ,Ripple ,Electrical engineering ,Buck–boost converter ,Energy Engineering and Power Technology ,Led driver ,Electrical and Electronic Engineering ,Current (fluid) ,business ,Ceramic capacitor - Published
- 2019
8. Quantum sensing of the electron electric dipole moment using ultracold entangled Fr atoms
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M Sato, Kenichi Harada, Bindiya Arora, K. S. Tanaka, T. Aoki, R Sreekantham, Takeshi Inoue, H. Nagahama, Y. Ichikawa, Y. Torii, T Nakashita, S Nagase, K. Nakamura, H Ikeda, M Ohtsuka, H. Ueno, Taku J. Sato, Anders Kastberg, Yasuhiro Sakemi, K Yamane, Hirokazu Kawamura, N Okamoto, N. Ozawa, T. Hayamizu, B. K. Sahoo, H. Haba, A Takamine, Atsushi Hatakeyama, A. Uchiyama, Yuji Matsuda, Institut de Physique de Nice (INPHYNI), Centre National de la Recherche Scientifique (CNRS)-Université Côte d'Azur (UCA)-Université Nice Sophia Antipolis (... - 2019) (UNS), and COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)
- Subjects
Physics ,Optical lattice ,Atom interferometer ,Physics and Astronomy (miscellaneous) ,[PHYS.PHYS.PHYS-ATOM-PH]Physics [physics]/Physics [physics]/Atomic Physics [physics.atom-ph] ,Materials Science (miscellaneous) ,Quantum limit ,Quantum sensor ,Measure (physics) ,Quantum entanglement ,7. Clean energy ,01 natural sciences ,Electron electric dipole moment ,Atomic and Molecular Physics, and Optics ,010305 fluids & plasmas ,[PHYS.QPHY]Physics [physics]/Quantum Physics [quant-ph] ,0103 physical sciences ,Physics::Atomic Physics ,Electrical and Electronic Engineering ,Atomic physics ,010306 general physics ,Quantum ,ComputingMilieux_MISCELLANEOUS - Abstract
We propose a method to measure the electron electric dipole moment (eEDM) using ultracold entangled francium (Fr) atoms trapped in an optical lattice, yielding an uncertainty below the standard quantum limit. Among the alkali atoms, Fr offers the largest enhancement factor to the eEDM. With a Fr based experiment, quantum sensing using quantum entangled states could enable a search for the eEDM at a level below 10−30 ecm. We estimate statistical and systematic errors attached to the proposed measurement scheme based on this quantum sensing technique. A successful quantum sensing of the eEDM could enable the exploration of new physics beyond the standard model of particle physics.
- Published
- 2021
9. Measurement of the temperature dependence of dwell time and spin relaxation probability of Rb atoms on paraffin surfaces using a beam-scattering method
- Author
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Kanta Asakawa, Yutaro Tanaka, Kenta Uemura, Norihiro Matsuzaka, Kunihiro Nishikawa, Yuki Oguma, Hiroaki Usui, and Atsushi Hatakeyama
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Atomic Physics (physics.atom-ph) ,FOS: Physical sciences ,Physics - Atomic Physics - Abstract
The scattering of Rb atoms on an anti-relaxation coating was studied. No significant change in the spin relaxation probability of Rb atoms by single scattering from a tetracontane surface was observed by cooling the film from 305 to 123 K. The mean surface dwell time was estimated using a time-resolved method.Delay-time spectra, from which mean surface dwell times can be estimated, were measured at 305, 153, and 123 K, with a time window of $9.3\times 10^{-5}$ s. The increase in mean surface dwell time with cooling from 305 to 123 K was smaller than $4.4\times 10^{-6}$ s, which is significantly smaller than the value expected from the mean dwell time at room temperature measured using the Larmor frequency shift. These results can be explained by assuming a small number of scattering components, with a mean surface dwell time at least three orders of magnitude longer than the majority component.
- Published
- 2021
10. Fundamental Physics with Cooled Radioactive Atoms
- Author
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Hirokazu Kawamura, Kenichi Harada, A. Uchiyama, Masatoshi Itoh, Junji Hisano, Yoshiro Takahashi, Takatoshi Aoki, Yasuhiro Sakemi, S. Ito, Atsushi Hatakeyama, and Takeshi Inoue
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Physics ,Fundamental physics ,Atomic physics - Published
- 2021
11. Characterization of a double torsion pendulum used to detect spin-induced torque based on Beth's experiment
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Atsushi Hatakeyama and Runa Yasuda
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Physics ,Angular momentum ,Quantum Physics ,Photon ,Classical Physics (physics.class-ph) ,FOS: Physical sciences ,Physics - Classical Physics ,Noise (electronics) ,Vibration ,Quantum electrodynamics ,Torsion pendulum clock ,Torque ,Sensitivity (control systems) ,Spin (physics) ,Quantum Physics (quant-ph) ,Instrumentation ,Optics (physics.optics) ,Physics - Optics - Abstract
We characterized a double torsion pendulum system, including measurements of the photon-spin-induced torque. Our experimental strategy was similar to that used in Beth's experiment, which was performed in 1936 to measure photon-spin-induced torque using forced oscillation caused by polarization modulation of light incident on a suspended object. Through simple passive isolation of the suspended object from external vibration noise, the achieved torque sensitivity was 2 x 10^{-17} N m in a measurement time of 10^4 s, which is close to the thermal noise limit and one order smaller than the minimum torque measured in Beth's experiment. The observed spin-induced torque exerted on the light-absorbing optics is consistent with the angular momentum transfer of hbar per photon., 13 pages, 6 figures. Major revision. Journal accepted manuscript
- Published
- 2021
12. Detection of radiation torque exerted on an alkali-metal vapor cell
- Author
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Yugo Nagata, Takahiro Kuroda, Yutaka Goto, Natsumi Chikakiyo, Runa Yasuda, and Atsushi Hatakeyama
- Subjects
Angular momentum ,Materials science ,Atomic Physics (physics.atom-ph) ,General Physics and Astronomy ,FOS: Physical sciences ,02 engineering and technology ,Radiation ,01 natural sciences ,Physics - Atomic Physics ,0103 physical sciences ,Irradiation ,Physics::Atomic Physics ,Hyperfine structure ,Circular polarization ,010302 applied physics ,Quantum Physics ,021001 nanoscience & nanotechnology ,Torsion spring ,lcsh:QC1-999 ,Magnetic field ,Condensed Matter - Other Condensed Matter ,Vacuum chamber ,Atomic physics ,0210 nano-technology ,Quantum Physics (quant-ph) ,lcsh:Physics ,Other Condensed Matter (cond-mat.other) - Abstract
We have developed a torsion balance to detect the rotation of a cell containing spin-polarized gaseous atoms to study angular momentum transfer from gaseous atoms to solid. A cesium vapor cell was hung from a thin wire in a vacuum chamber, and irradiated from the bottom with circularly polarized light tuned to the $D_2$ transition to polarize cesium atoms in the cell. By varying the light helicity at the resonance frequency of the torsion balance, we induced forced rotational oscillation of the cell and detected radiation torque exerted on the cesium vapor cell through the cesium atoms inside. The torque was particularly large when both hyperfine levels of cesium atoms were optically pumped with application of a longitudinal magnetic field. Further detailed study will provide new insights into spin-transfer processes at the gas-solid interface., Comment: 11 pages, 4 figures; v2: 12 pages, 4 figures. Corrected for a typo in Fig.2(a) in the journal version. Figures 3 and 4 were revised from v1. Some comments and references were also added to v1
- Published
- 2019
- Full Text
- View/download PDF
13. Scattering of an alkali-metal atomic beam on anti-spin-relaxation coatings
- Author
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Atsushi Hatakeyama, Kazane Okuma, Naota Sekiguchi, and Hiroaki Usui
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Condensed Matter::Quantum Gases ,Physics ,Diffraction ,Spin polarization ,Atomic Physics (physics.atom-ph) ,Scattering ,FOS: Physical sciences ,Film temperature ,chemistry.chemical_element ,02 engineering and technology ,Crystal structure ,021001 nanoscience & nanotechnology ,Alkali metal ,01 natural sciences ,Molecular physics ,Physics - Atomic Physics ,Rubidium ,Condensed Matter::Materials Science ,chemistry ,Condensed Matter::Superconductivity ,0103 physical sciences ,Physics::Atomic Physics ,Knudsen number ,010306 general physics ,0210 nano-technology - Abstract
We performed scattering experiments using a rubidium (Rb) atomic beam on paraffin films and measured the angular and velocity distributions of scattered atoms. The paraffin films were prepared in various ways and characterized by atomic force microscopy and X-ray diffraction. The films exhibited various roughnesses and crystal structures. The paraffin films preserved the spin polarization of the scattered atoms. The measured angular distributions of all prepared films were consistent with Knudsen's cosine law. The velocity distributions were well fitted by Maxwell's distribution, characterized by a temperature much closer to the film temperature than to the atomic-beam temperature. We therefore concluded that the Rb atoms were well thermalized with the paraffin films via single scattering events., 18 pages, 10 figures, to be submitted to Physical Review A
- Published
- 2018
14. Francium: Tool for Fundamental Symmetry Investigations
- Author
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A. Uchiyama, Tomohiro Hayamizu, Takahiro Aoki, Kenichi Harada, Hirokazu Kawamura, Takatoshi Aoki, K. Kato, Yasuhiro Sakemi, Atsushi Hatakeyama, Umakanth Dammalapati, Takeshi Inoue, Masatoshi Itoh, Sako Ito, and K. Sakamoto
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Theoretical physics ,Chemistry ,chemistry.chemical_element ,Atomic physics ,Symmetry (physics) ,Francium - Published
- 2017
15. Spectroscopic study of a diffusion-bonded sapphire cell for hot metal vapors
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Atsushi Hatakeyama, Takumi Sato, Naota Sekiguchi, and Kiyoshi Ishikawa
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Materials science ,Absorption spectroscopy ,Atomic Physics (physics.atom-ph) ,Physics::Instrumentation and Detectors ,Diffusion ,Analytical chemistry ,FOS: Physical sciences ,chemistry.chemical_element ,Physics::Optics ,01 natural sciences ,Chemical reaction ,010305 fluids & plasmas ,Rubidium ,Physics - Atomic Physics ,Optics ,0103 physical sciences ,Tube (fluid conveyance) ,Electrical and Electronic Engineering ,010306 general physics ,Engineering (miscellaneous) ,Glass tube ,business.industry ,Atomic and Molecular Physics, and Optics ,chemistry ,Sapphire ,business ,Diffusion bonding - Abstract
Characteristics of a diffusion-bonded sapphire cell for optical experiments with hot metal vapors were investigated. The sapphire cell consisted of sapphire-crystal plates and a borosilicate-glass tube, which were bonded to each other by diffusion bonding without any binders or glues. The glass tube was attached to a vacuum manifold using the standard method applied in glass processing, filled with a small amount of Rb metal by chasing with a torch, and then sealed. The cell was baked at high temperatures and optical experiments were then performed using rubidium atoms at room temperature. The sapphire cell was found to be vacuum tight, at least up to 350$^{\circ}$C, and the sapphire walls remained clear over all temperatures. From the optical experiments, the generation of a background gas was indicated after baking at 200$^{\circ}$C. The background gas pressure was low enough to avoid pressure broadening of absorption lines but high enough to cause velocity-changing collisions of Rb atoms. The generated gas pressure decreased at higher temperatures, probably due to chemical reactions., 5 pages, 4 figures, \copyright 2017 Optical Society of America. One print or electronic copy may be made for personal use only. Systematic reproduction and distribution, duplication of any material in this paper for a fee or for commercial purposes, or modifications of the content of this paper are prohibited
- Published
- 2017
16. Magnetic resonance of rubidium atoms passing through a multi-layered transmission magnetic grating
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S. Kurokawa, Atsushi Hatakeyama, and Y. Nagata
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Physics ,Frequency band ,Atomic Physics (physics.atom-ph) ,chemistry.chemical_element ,Resonance ,Physics::Optics ,FOS: Physical sciences ,02 engineering and technology ,Grating ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,Molecular physics ,Atomic and Molecular Physics, and Optics ,Physics - Atomic Physics ,Rubidium ,Magnetic field ,Magnetization ,Laser linewidth ,chemistry ,0103 physical sciences ,Physics::Atomic Physics ,010306 general physics ,0210 nano-technology ,Spectroscopy - Abstract
We measured the magnetic resonance of rubidium atoms passing through periodic magnetic fields generated by two types of multilayered transmission magnetic grating. One of the gratings reported here was assembled by stacking four layers of magnetic films so that the direction of magnetization alternated at each level. The other grating was assembled so that the magnetization at each level was aligned. For both types of grating, the experimental results were in good agreement with our calculations. We studied the feasibility of extending the frequency band of the grating and narrowing its resonance linewidth by performing calculations. For magnetic resonance precision spectroscopy, we conclude that the multi-layered transmission magnetic grating can generate periodic fields with narrower linewidths at higher frequencies when a larger number of layers is assembled at a shorter period length. Moreover, the frequency band of this type of grating can potentially achieve frequencies of up to hundreds of PHz., Comment: 5 pages, 8 figures
- Published
- 2017
- Full Text
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17. Application of IOR technology to a heavy-oil reservoir in the cold production
- Author
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Shinichi Hamamoto, Noriaki Shimokata, Atsushi Hatakeyama, and Akira Igarashi
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Petroleum engineering ,Environmental science ,Production (economics) ,Heavy oil reservoir - Published
- 2014
18. Development of a Dual Isotope Co-Magnetometer Using Laser Cooled Rubidium Toward Electron Electric Dipole Moment Measurement Using Francium
- Author
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Yasuhiro Sakemi, Takeshi Inoue, Kenichi Harada, A. Uchiyama, Takatoshi Aoki, Atsushi Hatakeyama, Masatoshi Itoh, Yoshiro Takahashi, K. S. Tanaka, and Hirokazu Kawamura
- Subjects
Physics ,History ,Magnetometer ,chemistry.chemical_element ,Laser ,Electron electric dipole moment ,Computer Science Applications ,Education ,law.invention ,Francium ,Rubidium ,chemistry ,law ,Dual isotope ,Atomic physics - Published
- 2019
19. Hydrocarbon Gas EOR to a Sandstone Reservoir in Rang Dong Field, Offshore Vietnam
- Author
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Aiko Nishizaki, Nguyen Chu Chuyen, Yohei Kawahara, Mutsuto Takagi, and Atsushi Hatakeyama
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chemistry.chemical_classification ,Hydrocarbon ,Petroleum engineering ,chemistry ,Submarine pipeline ,Geology - Published
- 2013
20. Non-negligible collisions of alkali atoms with background gas in buffer-gas-free cells coated with paraffin
- Author
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Atsushi Hatakeyama and Naota Sekiguchi
- Subjects
Alkali atoms ,Work (thermodynamics) ,Materials science ,Physics and Astronomy (miscellaneous) ,Atomic Physics (physics.atom-ph) ,Mean free path ,Buffer gas ,General Engineering ,Analytical chemistry ,FOS: Physical sciences ,General Physics and Astronomy ,chemistry.chemical_element ,02 engineering and technology ,Sense (electronics) ,021001 nanoscience & nanotechnology ,Spin relaxation time ,01 natural sciences ,Physics - Atomic Physics ,Rubidium ,chemistry ,0103 physical sciences ,010306 general physics ,0210 nano-technology - Abstract
We measured the rate of velocity-changing collisions (VCCs) between alkali atoms and background gas in buffer-gas-free anti-relaxation-coated cells. The average VCC rate in paraffin-coated rubidium vapor cells prepared in this work was $1 \times 10^{6}$ s$^{-1}$, which corresponds to $\sim 1$ mm in the mean free path of rubidium atoms. This short mean free path indicates that the background gas is not negligible in the sense that alkali atoms do not travel freely between the cell walls. In addition, we found that a heating process known as "ripening" increases the VCC rate, and also confirmed that ripening improves the anti-relaxation performance of the coatings., Comment: 5 pages, 4 figures
- Published
- 2016
21. The Challenge of Tight Sand Reservoir Development by Hydraulic Fracturing in Offshore Vietnam
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Kenji Hagiwara, Atsushi Hatakeyama, Shota Nakatsuka, Doan Manh Hung, Yohei Kawahara, and Yasuto Ariga
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Hydraulic fracturing ,Petroleum engineering ,Submarine pipeline ,Geology - Published
- 2012
22. RSOsPR10 Expression in Response to Environmental Stresses is Regulated Antagonistically by Jasmonate/Ethylene and Salicylic Acid Signaling Pathways in Rice Roots
- Author
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Noriko Ishii, Kentaroh Shimaya, Teruhiko Terakawa, Teruya Komano, Yuji Kamiya, Kaoru Takeuchi, Takashi Okamoto, Michael Riemann, Atsuko Gyohda, Atsushi Hatakeyama, Peter Nick, Makiko Tominaga, Madoka Kawakatsu, Yusuke Jikumaru, Tomokazu Koshiba, Makoto Hashimoto, Akira Endo, and Takeshi Nishimura
- Subjects
Salinity ,Physiology ,Mutant ,Cyclopentanes ,Plant Science ,Plant Roots ,chemistry.chemical_compound ,Plant Growth Regulators ,Gene Expression Regulation, Plant ,Stress, Physiological ,Plant defense against herbivory ,Oxylipins ,Jasmonate ,Transcription factor ,Plant Proteins ,Regulation of gene expression ,Chemistry ,Jasmonic acid ,Oryza ,Cell Biology ,General Medicine ,Ethylenes ,Cell biology ,Biochemistry ,RNA, Plant ,Mutation ,Signal transduction ,Salicylic Acid ,Salicylic acid ,Signal Transduction ,Transcription Factors - Abstract
Plant roots play important roles not only in the absorption of water and nutrients, but also in stress tolerance. Previously, we identified RSOsPR10 as a root-specific pathogenesis-related (PR) protein induced by drought and salt treatments in rice. Transcripts and proteins of RSOsPR10 were strongly induced by jasmonate (JA) and the ethylene (ET) precursor 1-aminocyclopropane-1-carboxylic acid (ACC), while salicylic acid (SA) almost completely suppressed these inductions. Immunohistochemical analyses showed that RSOsPR10 strongly accumulated in cortex cells surrounding the vascular system of roots, and this accumulation was also suppressed when SA was applied simultaneously with stress or hormone treatments. In the JA-deficient mutant hebiba, RSOsPR10 expression was up-regulated by NaCl, wounding, drought and exogenous application of JA. This suggested the involvement of a signal transduction pathway that integrates JA and ET signals in plant defense responses. Expression of OsERF1, a transcription factor in the JA/ET pathway, was induced earlier than that of RSOsPR10 after salt, JA and ACC treatments. Simultaneous SA treatment strongly inhibited the induction of RSOsPR10 expression and, to a lesser extent, induction of OsERF1 expression. These results suggest that JA/ET and SA pathways function in the stress-responsive induction of RSOsPR10, and that OsERF1 may be one of the transcriptional factors in the JA/ET pathway.
- Published
- 2011
23. An integrated approach combining tracer injection/monitoring and other surveillance application for reservoir management in Rang Dong basement reservoir
- Author
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Nguyen Chu Chuyen, Ooi Kiam Chai, and Atsushi Hatakeyama
- Subjects
geography ,geography.geographical_feature_category ,Radioactive tracer ,Petroleum engineering ,Water injection (oil production) ,Aquifer ,Produced water ,law.invention ,law ,TRACER ,Fluid dynamics ,Reservoir modeling ,Seawater ,Geology - Abstract
Rang Dong basement reservoir is a granitic naturally fractured reservoir. Unlike carbonate fractured system, basement matrix porosity is negligible. The storage and production are dominated by the fracture system. After primary depletion, water injection was commenced to further improve the oil recovery and production of the reservoir. Water injection in fractured reservoir is particularly challenging as it is very much dependant on the fracture connectivity, geometry and orientation. To manage the water injection strategy of the basement reservoir, a thorough understanding of the fluid flow is crucial. Therefore, radioactive tracer injection/monitoring were employed in different part of the field to obtain information on fluid path.Tracer injection/monitoring have been established as a proven and efficient technology to obtain information on well-to-well communication, heterogeneities and fluid dynamics. However, interpretation may in some cases not straight forward, therefore integration with other types of reservoir and production data are important to get a consistent and accurate interpretation.This paper demonstrates an integrated approach where it combined tracer injection/monitoring with other surveillance application for well planning and reservoir management. One of the surveillance is the monitoring of the water chemical composition through regular sampling and analysis of produced water. This method serves as the tracking of movement of formation/aquifer water and injected seawater. Another analysis involves the monitoring of produced water isotopes. Oil finger printing is also used as another source of information to be combined into the overall interpretation. Oil finger printing is used to identify any reservoir compartmentalization, reservoir extent and connectivity. Other reservoir data and applications used are well production performance, well pressure transient analyses, material balance analyses and etc.This paper documents some actual examples where the tracer injection/monitoring analyses integrated with all available information were used to derive at actual well planning or reservoir management strategy that was eventually applied in the field.
- Published
- 2010
24. Velocity-selective sublevel resonance of atoms with an array of current-carrying wires
- Author
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Atsushi Hatakeyama
- Subjects
Physics ,Range (particle radiation) ,Zeeman effect ,Physics and Astronomy (miscellaneous) ,Field (physics) ,Atomic Physics (physics.atom-ph) ,Oscillation ,Emphasis (telecommunications) ,General Engineering ,FOS: Physical sciences ,General Physics and Astronomy ,Resonance ,Physics - Atomic Physics ,Magnetic field ,symbols.namesake ,symbols ,Physics::Atomic Physics ,Atomic physics ,Doppler effect - Abstract
Resonance transitions between the Zeeman sublevels of optically-polarized Rb atoms traveling through a spatially periodic magnetic field are investigated in a radio-frequency (rf) range of sub-MHz. The atomic motion induces the resonance when the Zeeman splitting is equal to the frequency at which the moving atoms feel the magnetic field oscillating. Additional temporal oscillation of the spatially periodic field splits a motion-induced resonance peak into two by an amount of this oscillation frequency. At higher oscillation frequencies, it is more suitable to consider that the resonance is mainly driven by the temporal field oscillation, with its velocity-dependence or Doppler shift caused by the atomic motion through the periodic field. A theoretical description of motion-induced resonance is also given, with emphasis on the translational energy change associated with the internal transition., Comment: 7 pages, 3 figures, final version
- Published
- 2008
25. [Untitled]
- Author
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Akinobu Shiroyama, Atsushi Hatakeyama, Akira Suto, Kenji Kobayashi, Yoshihiro Nishida, and Masayuki Saito
- Subjects
Fishery ,Oceanography ,Geography ,Evaluation methods ,General Medicine - Published
- 2008
26. Doubly-resonant coherent excitation of HCI planar channeled in a Si crystal
- Author
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Y Nakano, S. Masugi, Ken-ichiro Komaki, C. Kondo, Yasunori Yamazaki, E. Takada, Atsushi Hatakeyama, Toshiyuki Azuma, T. Muranaka, and T. Murakami
- Subjects
Crystal ,History ,Planar ,Chemistry ,Ionization ,Resonance ,Atomic physics ,Excitation ,Computer Science Applications ,Education ,Ion - Abstract
We investigated resonant coherent excitation of H-like Ar17+ and He-like Ar16+ ions planar channeled in a Si crystal under the V-type and ladder-type double resonance conditions. In both cases, we observed distinct enhancement in the ionized fraction of the transmitted ions when the double resonance conditions were satis.ed. In the ladder-type configuration, the enhancement indicates that the doubly-excited 2p2 state of He-like Ar16+was produced through doubly-resonant coherent excitation.
- Published
- 2007
27. Measurement of the Hyperfine Splitting of Alkali Atoms in Superfluid Helium for Laser Spectroscopy of Atoms with Unstable Nuclei
- Author
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Hazuki Shirai, Tomoya Sato, Shuichiro Kojima, Yuta Ebara, Tohru Kobayashi, Hideki Ueno, Miki Hayasaka, Takahiro Suzuki, Yuichi Ichikawa, Takashi Wakui, T. Fujita, Xiaofei Yang, Koichiro Asahi, Atsushi Hatakeyama, Takeshi Furukawa, Y. Mitsuya, Hitoshi Odashima, K. Imamura, Yuichi Ohtomo, and Yukari Matsuo
- Subjects
Alkali atoms ,Chemistry ,Atomic physics ,Spectroscopy ,Hyperfine structure ,Superfluid helium-4 - Published
- 2015
28. Development of Laser Light Sources for Trapping Radioactive Francium Atoms Toward Tests of Fundamental Symmetries
- Author
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Kenichi Imai, Masatoshi Itoh, Kenichi Harada, Takatoshi Aoki, Hirokazu Kawamura, T. Murakami, S. Ando, Tomohiro Hayamizu, A. Uchiyama, T. Ishikawa, Tomotsugu Wakasa, Hidetomo Yoshida, S. Ezure, Kichiji Hatanaka, Atsushi Hatakeyama, Takahiro Aoki, K. Kato, Takeshi Inoue, Yasuhiro Shimizu, Yasuhiro Sakemi, H. Arikawa, and Tomoya Sato
- Subjects
Physics ,Cyclotron ,chemistry.chemical_element ,Trapping ,Polarization (waves) ,Laser ,Rubidium ,law.invention ,Francium ,chemistry ,law ,Atomic physics ,Spectroscopy ,Hyperfine structure - Published
- 2015
29. Study of 11Be structure through β-delayed decays from polarized 11Li
- Author
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Atsushi Hatakeyama, M. Yagi, H. Yano, Yoshikazu Hirayama, K. P. Jackson, C. D. P. Levy, H. Izumi, Tadashi Shimoda, and Hiroari Miyatake
- Subjects
Physics ,Nuclear and High Energy Physics ,Decay scheme ,Spins ,Excited state ,media_common.quotation_subject ,Neutron ,Atomic physics ,Beta decay ,Delayed neutron ,Asymmetry ,Coincidence ,media_common - Abstract
The excited states in the light neutron-rich nucleus 11Be have been studied through the β-delayed neutron- and γ-decays from spin-polarized 11Lig.s.. The level scheme and decay scheme of 11Be∗ are established from the β–γ, β–n and β–n–γ coincidences, and the spins and parities for 7 levels in 11Be are firmly assigned from the β-decay asymmetries measured in coincidence with the delayed radiations. The neutron-spectroscopic factors of the levels in 11Be are also determined. Some of the levels show good accord with predictions by the anti-symmetrized molecular dynamics (AMD) theory, which predicts various types of 2α-cluster states in the rotational bands and a single α-cluster state.
- Published
- 2005
30. Relaxation of Cs atomic polarization at surface coatings characterized by X-ray photoelectron spectroscopy
- Author
-
Tomohito Shimizu, Kazuki Meguro, Takemasa Moriya, Hideki Nakazawa, Atsushi Hatakeyama, Toshihiro Niwano, and Kotaro Kushida
- Subjects
Condensed Matter - Materials Science ,Materials science ,Physics and Astronomy (miscellaneous) ,Silicon ,Atomic Physics (physics.atom-ph) ,Annealing (metallurgy) ,General Engineering ,Analytical chemistry ,technology, industry, and agriculture ,Materials Science (cond-mat.mtrl-sci) ,FOS: Physical sciences ,General Physics and Astronomy ,chemistry.chemical_element ,Oxygen ,Spectral line ,Physics - Atomic Physics ,Carbon film ,chemistry ,X-ray photoelectron spectroscopy ,Caesium ,Spin relaxation - Abstract
Paraffin coatings on glass slides were investigated through both X-ray photoelectron spectroscopy (XPS) and spin relaxation measurement for cesium (Cs) vapor. The components of the glass substrate, such as silicon (Si) and oxygen (O), existed in the XPS spectra of the coated slides, indicating the imperfection of the prepared paraffin coatings. The substrate was not observed after the annealing of the coatings in Cs vapor, which is known as a `ripening' process for spin relaxation measurement. We found a general trend that effective anti-spin relaxation performance requires high paraffin and low Cs coverage on the surface. We also examined a type of diamond-like carbon (DLC) film, anticipating the effect of anti-spin relaxation; our attempts have failed to date., 6 pages, 6 figures. v2: an extra figure generated in the first submission has been removed. v3: Final author version for publication on JJAP
- Published
- 2014
31. An effective method for trapping ion beams in superfluid helium for laser spectroscopy experiments
- Author
-
T. Shinozuka, T. Sonoda, Takashi Wakui, Hideki Ueno, S. Nishimura, Miki Hayasaka, Xiaofei Yang, Yoko Ishibashi, Y. Mitsuya, M. Nishimura, H. Fujita, Yuta Ebara, Yukari Matsuo, Takeshi Furukawa, Y. Kondo, Kenichiro Yoneda, Hazuki Shirai, K. Imamura, Michiharu Wada, Tohru Kobayashi, Yuichi Ichikawa, Koichiro Asahi, Atsushi Hatakeyama, T. Ito, and Tadashi Shimoda
- Subjects
Physics ,Spins ,QC1-999 ,chemistry.chemical_element ,Scintillator ,Laser ,Ion ,law.invention ,chemistry ,law ,Physics::Atomic Physics ,Atomic physics ,Spectroscopy ,Beam (structure) ,Helium ,Superfluid helium-4 - Abstract
A novel laser spectroscopy technique -“OROCHI” (Optical Radioisotopes Observation in Condensed Helium as Ion-catcher) has been proposed. This method aimed to investigate the structure of exotic nuclei systematically by measuring nuclear spins and moments. For in-situ laser spectroscopy of atoms in He II, a method to trap atoms precisely at the observation region of laser is highly needed. In this work, a setup composed of a degrader, two plastic scintillators and a photon detection system is further tested and verified for adjusting and checking the stopping position of 84–87 Rb beam. Details of the current setup, experimental results using this method are presented.
- Published
- 2014
32. Optical and magnetic properties of a transparent garnet film for atomic physics experiments
- Author
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Yugo Nagata, Hiroyuki Shimada, Mari Saito, Takayuki Ishibashi, Atsushi Hatakeyama, Ryoichi Tajima, and Ryota Kiyosawa
- Subjects
Materials science ,Magnetic domain ,Optical isolator ,Optical communication ,General Physics and Astronomy ,Physics::Optics ,01 natural sciences ,law.invention ,010309 optics ,Magnetic mirror ,symbols.namesake ,Condensed Matter::Materials Science ,Optics ,law ,Laser cooling ,0103 physical sciences ,Faraday effect ,010306 general physics ,Faraday rotator ,business.industry ,lcsh:QC1-999 ,Wavelength ,symbols ,Atomic physics ,business ,lcsh:Physics - Abstract
We investigated the optical and magnetic properties of a transparent magnetic garnet with a particular focus on its applications to atomic physics experiments. The garnet film used in this study was a magnetically soft material that was originally designed for a Faraday rotator at optical communication wavelengths in the near infrared region. The film had a thickness of 2.1 μm and a small optical loss at a wavelength of λ=780 nm resonant with Rb atoms. The Faraday effect was also small and, thus, barely affected the polarization of light at λ=780 nm. In contrast, large Faraday rotation angles at shorter wavelengths enabled us to visualize magnetic domains, which were perpendicularly magnetized in alternate directions with a period of 3.6 μm. We confirmed the generation of an evanescent wave on the garnet film, which can be used for the optical observation and manipulation of atoms on the surface of the film. Finally, we demonstrated a magnetic mirror for laser-cooled Rb atoms using the garnet film.
- Published
- 2016
33. Time Course of Leucine-induced 4E-BP1 and S6K1 Phosphorylation in the Liver and Skeletal Muscle of Rats
- Author
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Sachiyo Hirayama, Atsushi Hatakeyama, Fumiaki Yoshizawa, Takashi Nagasawa, Haruhito Sekizawa, and Kunio Sugahara
- Subjects
Male ,medicine.medical_specialty ,Time Factors ,Administration, Oral ,Medicine (miscellaneous) ,P70-S6 Kinase 1 ,Biology ,environment and public health ,Eukaryotic translation ,Leucine ,Internal medicine ,Eukaryotic initiation factor ,medicine ,Animals ,Phosphorylation ,Rats, Wistar ,Muscle, Skeletal ,Protein kinase A ,Nutrition and Dietetics ,Ribosomal Protein S6 Kinases ,Phosphotransferases ,Intracellular Signaling Peptides and Proteins ,Skeletal muscle ,Phosphoproteins ,Rats ,enzymes and coenzymes (carbohydrates) ,medicine.anatomical_structure ,Endocrinology ,Liver ,Ribosomal protein s6 ,Carrier Proteins - Abstract
The purpose of the current study was to assess the involvement of the branched-chain amino acid leucine in the regulation of translation initiation in the liver and to compare the time course of leucine action on the translation initiation in the liver and skeletal muscle of rats. The phosphorylation of the eukaryotic initiation factor (eIF)4E-binding protein 1 (4E-BP1) frees eIF4E and stimulates protein synthesis by accelerating translation initiation. Phosphorylation of the 70-kDa ribosomal protein S6 kinase (S6K) is thought to be involved in regulating the synthesis of certain ribosomal proteins and other selected proteins with polypyrimidine clusters near the transcription start site. Food-deprived (18 h) male rats were orally administered 135 mg/100 g body weight L-leucine and sacrificed at 0, 1, 3, or 6 h after administration. The oral administration of leucine resulted in an enhanced phosphorylation of 4E-BP1 and S6K1 in both the liver and skeletal muscle. A time-dependent change in the phosphorylation state of 4E-BP1 and S6K1 was more acute in the skeletal muscle than in the liver and closely paralleled the changes in plasma leucine concentration. Our results indicate that the primary mediator in 4E-BP1 phosphorylation and S6K1 phosphorylation by the oral administration of leucine is an increase in the plasma concentration of leucine. Furthermore, our findings suggest differential sensitivity in the tissue response to oral administration of leucine.
- Published
- 2001
34. Slow Spin Relaxation of Rb Atoms Confined in Glass Cells Filled with Dense4HeGas at 1.85 K
- Author
-
Albert Young, Tsutomu Yabuzaki, S. Hara, K. Oe, Atsushi Hatakeyama, J. Arai, and Kaiichiro Ota
- Subjects
Metal ,Spin–spin relaxation ,Optical pumping ,Materials science ,visual_art ,visual_art.visual_art_medium ,General Physics and Astronomy ,Electronic spin ,Cw laser ,Atomic physics ,Spin relaxation - Abstract
At temperatures below 2.1 K, long-lived gaseous Rb atoms in glass cells have been generated with a simple method: irradiating the cells, containing ${}^{4}\mathrm{He}$ gas and Rb metal, with a cw laser. The obtained atomic Rb density ( $\ensuremath{\sim}{10}^{8}{\mathrm{cm}}^{\ensuremath{-}3}$) decreases with a $1/e$ time constant of about 10 s at 1.85 K. We have performed optical pumping of the Rb atoms and measured the longitudinal electronic spin relaxation time at 1.85 K as well. For processes (such as Rb-He collisions) which do not remove the atomic Rb from the vapor, this relaxation time is found to be about $60\ifmmode\pm\else\textpm\fi{}15\mathrm{s}$.
- Published
- 2000
35. High Cycle Fatigue Strength and Fatigue Crack Properties of Semi-Liquid Die Casting Aluminum Alloys
- Author
-
Atsushi Hatakeyama, Takashi Matsumura, Yasuo Ochi, and Ryoichi Shibata
- Subjects
business.product_category ,Materials science ,Mechanical Engineering ,Metallurgy ,chemistry.chemical_element ,Fracture mechanics ,Fatigue limit ,Die casting ,Crack closure ,chemistry ,Mechanics of Materials ,Aluminium ,Casting (metalworking) ,Die (manufacturing) ,General Materials Science ,business ,Eutectic system - Abstract
Rotating bending fatigue tests were carried out on semi-liquid die casting aluminum alloys. Compared with the conventional casting, the semi-liquid die casting could reduce cast defects and porosities of casting aluminum alloys, and could miniatureize structrue size, therefore fatigue life of semi-liquid die casting aluminum alloys were expected to be improved. And fatigue crack initiation sites were alternative of cast defects and eutectic silicon particles. According to crack initiation sites, the crack initiation life varied, and crack propagation property depended on the form and the distribution of eutectic silicon particles. Therefore the fatigue strength of aluminum alloys was higher in turn of the semi-liquid die cast material that cracked from eutectic silicon particles, the same material that cracked from porosity and the conventional die cast material (AC 4CH). As a result, as to aluminum alloys, the fatigue life was estimated from the crack initiation life and the crack propagation life, and obtained fatigue life prediction gave good agreement with the experiment value.
- Published
- 2000
36. Dechlorination Treatment of Polyvinyl Chloride
- Author
-
Yoshishige Kato, Atsushi Hatakeyama, and Heiji Enomoto
- Subjects
Polyvinyl chloride ,chemistry.chemical_compound ,Waste management ,Chlorinated polyvinyl chloride ,Chemistry ,Medical waste ,Hydrothermal reaction - Abstract
ポリ塩化ビニル廃棄物の新しい処理方法として, 高温熱水中において脱塩素化を行う方法について検討した。その結果, 金属鉄あるいはアルカリの存在のもとに, 300℃の亜臨界高温熱水中では1時間程度の反応時間で, また250℃では20時間程度で, ほぼ100%の脱塩素化が可能であることがわかった。さらに, 金属鉄のみの存在下では主に置換反応による脱塩素化が進行し外見上高分子の分解反応の進行はほとんど認められず, 反応後には溶融固化した固体が得られること, および, アルカリのみの存在下では分解反応と脱塩素化反応が同時に進行し, 反応生成物のほとんどが水溶性あるいは非水溶性液体となり固体残さは極めて少ないことがわかった。また, 金属鉄とアルカリが共存する場合, 亜臨界では主に脱塩素化反応が進行し分解反応は抑制されるが, 超臨界では分解反応も速やかに進行する。本方法は, 感染性医療系廃棄物の施設内処理に要求される滅菌処理方法として「医療廃棄物処理ガイドライン」に沿ったものであり, プラスチック製医療系廃棄物の施設内処理方法としても有効と考えられる。
- Published
- 1995
37. Spin nutation induced by atomic motion in a magnetic lattice
- Author
-
Y. Shiraishi, Atsushi Hatakeyama, and Y. Kobayashi
- Subjects
Physics ,Angular momentum ,Atomic Physics (physics.atom-ph) ,Nutation ,Dephasing ,FOS: Physical sciences ,Magnetic lattice ,chemistry.chemical_element ,Atomic and Molecular Physics, and Optics ,Physics - Atomic Physics ,Rubidium ,chemistry ,Lattice (order) ,Atom ,Atomic physics ,Beam (structure) - Abstract
An atom moving in a spatially periodic field experiences a temporary periodic perturbation and undergoes a resonance transition between atomic internal states when the transition frequency is equal to the atomic velocity divided by the field period. We demonstrated that spin nutation was induced by this resonant transition in a polarized rubidium (Rb) atomic beam passing through a magnetic lattice. The lattice was produced by current flowing through an array of parallel wires crossing the beam. This array structure, reminiscent of a multiwire chamber for particle detection, allowed the Rb beam to pass through the lattice at a variety of incident angles. The dephasing of spin nutation was reduced by varying the incident angle., Comment: 11 pages, 4 figures, submitted to Phys. Rev. A
- Published
- 2010
38. Midkine and its clinical significance in endometrial carcinoma
- Author
-
Hitoshi Niikura, Shinya Ikematsu, Mitsuyo Matsumoto, Nobuo Yaegashi, Kenji Kadomatsu, K. Tanabe, Satoru Nagase, Shin Ichi Hayashi, Atsushi Hatakeyama, Kiyoshi Ito, and Tadao Takano
- Subjects
Oncology ,Cancer Research ,medicine.medical_specialty ,medicine.medical_treatment ,Enzyme-Linked Immunosorbent Assay ,Gastroenterology ,Metastasis ,Internal medicine ,Carcinoma ,Biomarkers, Tumor ,Medicine ,Humans ,Clinical significance ,Neoplasm Invasiveness ,Nerve Growth Factors ,Neoplasm Staging ,Midkine ,biology ,business.industry ,Growth factor ,Cancer ,General Medicine ,Middle Aged ,medicine.disease ,Prognosis ,Endometrial Neoplasms ,Lymphatic Metastasis ,biology.protein ,Immunohistochemistry ,Female ,business ,Carcinoma, Endometrioid ,Human cancer - Abstract
Midkine (MK) is a secreted heparin-binding growth factor. Several types of human cancer have increased MK expression with elevated serum levels. The purpose of this study was to determine whether MK was expressed in endometrial carcinoma and to evaluate the clinicopathological significance of serum MK in patients with endometrial carcinoma. Immunohistochemical expression of MK was evaluated in 85 endometrial carcinoma samples and 33 controls. MK expression was significantly higher in the carcinomas than in normal endometrium (P < 0.001). Interestingly, MK expression was highest at the margins of invasion and low in the superficial areas of the tumor samples. Using ELISA, we compared serum MK concentration in 120 endometrial carcinoma patients with the concentration in 46 patients with benign gynecologic tumors. Serum MK value in patients with cancer was significantly higher than that in the patients with benign diseases (P = 0.01). Patients with positive lymph node metastasis or recurrence, or cancer death, had a higher serum MK level (P = 0.008, P = 0.009, respectively). In conclusion, MK immunoreactivity in endometrial carcinoma is significantly higher than in normal endometrium. Additionally, preoperative serum MK levels are significantly correlated with prognosis and the presence of lymph node metastasis. Thus, MK may be a useful serum biomarker for identifying high risk patients of endometrial carcinoma.
- Published
- 2008
39. Measurement of a Long Electronic Spin Relaxation Time of Cesium Atoms in Superfluid Helium
- Author
-
H. Izumi, Yoshimitsu Fukuyama, T. Furukawa, Yukari Matsuo, Tadashi Shimoda, Atsushi Hatakeyama, and T. Kobayashi
- Subjects
Condensed Matter::Quantum Gases ,Physics ,Spin–lattice relaxation ,General Physics and Astronomy ,chemistry.chemical_element ,Electron ,Superfluidity ,chemistry ,Impurity ,Atom ,Physics::Atomic and Molecular Clusters ,Physics::Atomic Physics ,Atomic physics ,Spin (physics) ,Helium ,Superfluid helium-4 - Abstract
The longitudinal electronic spin relaxation time of Cs atoms optically polarized in superfluid helium (He II, 1.5 K) has been measured with special care to cope with a serious decrease in the number of Cs atoms in the observation region. This decrease, mainly caused by helium convection in introducing the atoms into He II by laser sputtering, was significantly reduced using a new atom implantation method. Combined with a careful correction for the number of atoms, we have determined the relaxation time to be 2.24(19) s or longer, roughly twice as long as that in solid He.
- Published
- 2006
40. Classification of Light-Induced Desorption of Alkali Atoms in Glass Cells Used in Atomic Physics Experiments
- Author
-
Markus Wilde, Atsushi Hatakeyama, and Katsuyuki Fukutani
- Subjects
Materials science ,Atomic Physics (physics.atom-ph) ,Ionic bonding ,FOS: Physical sciences ,Bioengineering ,Context (language use) ,Surfaces and Interfaces ,Substrate (electronics) ,Condensed Matter Physics ,Alkali metal ,Surfaces, Coatings and Films ,Physics - Atomic Physics ,Condensed Matter - Other Condensed Matter ,Electron transfer ,Mechanics of Materials ,Desorption ,Atom ,Ultraviolet light ,Physics::Atomic and Molecular Clusters ,Physics::Atomic Physics ,Atomic physics ,Biotechnology ,Other Condensed Matter (cond-mat.other) - Abstract
We attempt to provide physical interpretations of light-induced desorption phenomena that have recently been observed for alkali atoms on glass surfaces of alkali vapor cells used in atomic physics experiments. We find that the observed desorption phenomena are closely related to recent studies in surface science, and can probably be understood in the context of these results. If classified in terms of the photon-energy dependence, the coverage and the bonding state of the alkali adsorbates, the phenomena fall into two categories: It appears very likely that the neutralization of isolated ionic adsorbates by photo-excited electron transfer from the substrate is the origin of the desorption induced by ultraviolet light in ultrahigh vacuum cells. The desorption observed in low temperature cells, on the other hand, which is resonantly dependent on photon energy in the visible light range, is quite similar to light-induced desorption stimulated by localized electronic excitation on metallic aggregates. More detailed studies of light-induced desorption events from surfaces well characterized with respect to alkali coverage-dependent ionicity and aggregate morphology appear highly desirable for the development of more efficient alkali atom sources suitable to improve a variety of atomic physics experiments., 6 pages, 1 figure; minor corrections made, published in e-Journal of Surface Science and Nanotechnology at http://www.jstage.jst.go.jp/article/ejssnt/4/0/4_63/_article
- Published
- 2005
41. Motion-Induced Magnetic Resonance of Rb Atoms in a Periodic Magnetostatic Field
- Author
-
Yasunori Yamazaki, Ken-ichiro Komaki, Y. Enomoto, and Atsushi Hatakeyama
- Subjects
Physics ,Condensed Matter::Quantum Gases ,Zeeman effect ,Field (physics) ,Atomic Physics (physics.atom-ph) ,General Physics and Astronomy ,Resonance ,FOS: Physical sciences ,Electromagnetic radiation ,Magnetic field ,Physics - Atomic Physics ,symbols.namesake ,Excited state ,Atom ,symbols ,Physics::Atomic Physics ,Atomic physics ,Excitation - Abstract
We demonstrate that transitions between Zeeman-split sublevels of Rb atoms are resonantly induced by the motion of the atoms (velocity: about 100 m/s) in a periodic magnetostatic field (period: 1 mm) when the Zeeman splitting corresponds to the frequency of the magnetic field experienced by the moving atoms. A circularly polarized laser beam polarizes Rb atoms with a velocity selected using the Doppler effect and detects their magnetic resonance in a thin cell, to which the periodic field is applied with the arrays of parallel current-carrying wires., Comment: 4 pages, 4 figures; minor corrections, Ref. [9] removed, published in PRL
- Published
- 2005
- Full Text
- View/download PDF
42. The new beta-NMR facility at TRIUMF and applications in semiconductors
- Author
-
S. R. Kreitzman, R. F. Kiefl, G.D. Morris, Jak Chakhalian, Y. Hirayama, Richard Baartman, S. Daviel, W. A. MacFarlane, Zaher Salman, Kim H. Chow, Donald J. Arseneau, Atsushi Hatakeyama, E. Reynard, R. Poutissou, Bassam Hitti, P. Amaudruz, and C. D. P. Levy
- Subjects
Radioactive ion beams ,Materials science ,Meson ,business.industry ,Semiconductor materials ,Cyclotron ,Resonance ,Condensed Matter Physics ,Electronic, Optical and Magnetic Materials ,law.invention ,Nuclear physics ,Semiconductor ,Nuclear magnetic resonance ,law ,Electrical and Electronic Engineering ,business - Abstract
A new facililty for conducting beta-detected nuclear magnetic resonance (beta-NMR) investigations of condensed matter systems has recently been constucted at TriUniversity Meson Facility in Vancouver, Canada. The unique features of this new facility are described, and some preliminary results on Li-8(+) in GaAs are presented. (C) 2003 Elsevier B.V. All rights reserved.
- Published
- 2003
43. Atomic alkali-metal gas cells at liquid-helium temperatures: Loading by light-induced atom desorption
- Author
-
Katsunari Enomoto, Tsutomu Yabuzaki, N. Sugimoto, and Atsushi Hatakeyama
- Subjects
Condensed Matter::Quantum Gases ,Physics ,Liquid helium ,Transition temperature ,Evaporation ,Analytical chemistry ,chemistry.chemical_element ,Alkali metal ,Atomic and Molecular Physics, and Optics ,law.invention ,chemistry ,law ,Desorption ,Atom ,Physics::Atomic and Molecular Clusters ,Physics::Atomic Physics ,Irradiation ,Atomic physics ,Helium - Abstract
We have studied the loading of gaseous alkali-metal atoms into glass cells held at about 2 K by light-induced atom desorption (LIAD). In LIAD loading, the cell containing dense helium gas and a small amount of alkali metal is irradiated with cw laser light. This technique has two unique features to be investigated: alkali-metal atoms are desorbed, even by weak laser irradiation, from the cell walls not covered visibly with alkali metal, and loading efficiency is much higher below the superfluid transition temperature for the helium inside the cell than above this temperature. On the basis of extensive experimental studies for Rb presented in this paper, we give a consistent picture of the loading mechanism: alkali-metal atoms are optically desorbed from alkali-metal particles on the walls, then transported effectively into the cell volume by helium-gas flow produced by the continuous evaporation of the helium film, which is supplied by the superfluid-film flow on the walls from the bulk liquid helium at the bottom of the cell.
- Published
- 2002
44. Resonant Coherent Excitation of Hydrogenlike Fe25+ in a Ge crystal
- Author
-
Y Nakano, K Inoue, Eiichi Takada, K. Komaki, Yohta Nakai, C Watanabe, Atsushi Hatakeyama, Toshiyuki Azuma, T Masunaga, and T. Murakami
- Subjects
Crystal ,History ,Materials science ,Planar ,Germanium crystal ,Atomic physics ,Fluorescence ,Excitation ,Computer Science Applications ,Education ,Ion - Abstract
An extremely-thin Germanium crystal (0.8 μm-thick) has been firstly exploited in the resonant coherent excitation (RCE) experiment. The 460 MeV/u H-like Fe25+ ions were incident on the Ge crystal under the (220) planar channeling as well as non-channeling conditions. The RCE from 1s to 2p1/2 and 2p3/2 states were successfully observed as an enhancement of the x-ray fluorescence.
- Published
- 2014
45. Convoy electron emission following ionization of highly-charged ions excited by resonant coherent excitation
- Author
-
Y Nakano, S Ohtsuki, T. Murakami, Yoichi Nakai, Toshiyuki Azuma, Ken-ichiro Komaki, T Shindo, E. Takada, K Metoki, S Suda, and Atsushi Hatakeyama
- Subjects
History ,education.field_of_study ,Chemistry ,Population ,Resonance ,Electron ,Charged particle ,Computer Science Applications ,Education ,Ion ,Excited state ,Ionization ,Atomic physics ,education ,Excitation - Abstract
Projectile ionization of highly-charged Ar and Fe ions in the excited states passing relativistically fast through a thin crystalline foil was experimentally studied. We selectively controlled the population of the excited states of the projectiles, and their alignment by choosing a specific m-state through three-dimensional resonant coherent excitation technique by periodical electric fields in a crystalline. We measured energy-differential spectra of electron emission released from projectiles at zero degree. Under the resonance condition, we found an evident enhancement of the convoy electron yield, which reflects the electron momentum distribution of the initial bound state of the excited ions.
- Published
- 2012
46. Alignment of fast heavy ions using periodic crystal fields
- Author
-
Toshiyuki Azuma, K Metoki, K. Komaki, Atsushi Hatakeyama, Yasunori Yamazaki, Eiichi Takada, T. Murakami, Yohta Nakai, and Y Nakano
- Subjects
Crystal ,Physics ,History ,Field (physics) ,Linear polarization ,Excited state ,Atomic physics ,Anisotropy ,Charged particle ,Excitation ,Computer Science Applications ,Education ,Ion - Abstract
We demonstrate the alignment of H-like and He-like heavy ions by three-dimensional resonant coherent excitation in a thin crystalline target. The projectile ions experienced a linearly polarized oscillating field in a crystal and were excited to a specific magnetic substate, forming the aligned 2P state. We prepared the different directions of the aligned states and observed the anisotropy of deexcitation x-ray emission, which was in good agreement with theoretical estimates.
- Published
- 2009
47. Double K-shell excitation of He-like Ar16+and Li-like Ar15+ions using periodic crystal fields
- Author
-
Yasunori Yamazaki, T. Murakami, Y Nakano, Yohta Nakai, Atsushi Hatakeyama, Y Takano, Toshiyuki Azuma, K. Komaki, K Metoki, and Eiichi Takada
- Subjects
History ,Chemistry ,Electron shell ,Resonance ,Electron ,Charged particle ,Computer Science Applications ,Education ,Ion ,Crystal ,Excited state ,Physics::Atomic and Molecular Clusters ,Atomic physics ,Excitation - Abstract
We exploited the double resonance technique in three-dimensional resonant coherent excitation to the production of hollow He-like and Li-like heavy ions. The two K-shell electron were sequentially excited to the L-shell using two frequency components of the oscillating fields arising from the different arrays of atomic planes in a Si crystal.
- Published
- 2009
48. Initial state dependence of convoy electrons emitted from the excited ions by resonant coherent excitation
- Author
-
Yasunori Yamazaki, Y Nakano, Atsushi Hatakeyama, Yohta Nakai, K. Komaki, Eiichi Takada, Toshiyuki Azuma, K Metoki, and T. Murakami
- Subjects
History ,Chemistry ,Excited state ,Bound state ,Resonance ,Electron ,Atomic physics ,Ground state ,Charged particle ,Excitation ,Computer Science Applications ,Education ,Ion - Abstract
Convoy electrons emitted from 416 MeV/u heliumlike Ar16+ ions excited by three-dimensional resonant coherent excitation (3D-RCE) have been explored. The 1s electron in the ground state was excited to the 2p state by a periodic crystal field during the passage through a Si crystal and released into the continuum by collisions with target atoms to form a cusp-shaped peak in the energy distribution, referred to as convoy electron. Under the resonance condition, we found not only enhancement of the convoy electron yield but also significant narrowing in the energy distribution, reflecting the initial bound state momentum distribution of the excited ions. This suggests that RCE is well-suited to study fast ion collisions involving the specific excited state.
- Published
- 2009
49. Magnetic resonance of atoms passing through a magnetic lattice
- Author
-
Y Kobayashi and Atsushi Hatakeyama
- Subjects
Condensed Matter::Quantum Gases ,Larmor precession ,History ,Chemistry ,Resonance ,Magnetic lattice ,Laser pumping ,Magnetic susceptibility ,Computer Science Applications ,Education ,Magnetic field ,Paramagnetism ,Spin echo ,Physics::Atomic Physics ,Atomic physics - Abstract
We have observed magnetic resonance of Rb atoms passing through a periodic magnetic field produced by a stack of planar arrays of parallel current-carrying wires ("magnetic lattice"). The magnetic resonance occurs between the Zeeman-split sublevels of Rb atoms when the frequency of the field oscillation that the atoms experience equals the transition frequency. A pump laser polarizes Rb atoms with a specific velocity selected by the Doppler effect and a probe laser detects the magnetic resonance. The obtained narrowest resonance lines have widths mainly determined by the transit-time broadening.
- Published
- 2009
50. Resonant coherent excitation of Li-like Ar15+Ions in a Thin Si crystal
- Author
-
K. Komaki, Toshiyuki Azuma, T. Murakami, Yohta Nakai, Atsushi Hatakeyama, Y Nakano, Yasunori Yamazaki, Eiichi Takada, and T Inoue
- Subjects
History ,Materials science ,Nuclear Theory ,Computer Science Applications ,Education ,Ion ,Crystal ,symbols.namesake ,Planar ,Stark effect ,Vacancy defect ,Physics::Atomic and Molecular Clusters ,symbols ,Atomic physics ,Excitation - Abstract
We investigated resonant coherent excitation (RCE) of 445 MeV/u Li-like Ar15+ under the planar channeling and non-channeling conditions. The K-shell and L-shell excitations are observed as decreases in the survival fraction of the Ar15+ ions after passing through a thin Si crystal. RCE under the planar channeling condition provides the opportunity to study a strong static Stark effect on the Li-like system with K-shell or L-shell vacancy. Under the non-channeling conditions, the observed excitation energies and the reported theoretical calculations were in reasonable agreement.
- Published
- 2009
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