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Rapp, L.*; Matsuoka, Takeshi*; Firestein, K. L.*; Sagae, Daisuke*; Habara, Hideaki*; Mukai, Keiichiro*; Tanaka, Kazuo*; Gamaly, E. G.*; Kodama, Ryosuke*; Seto, Yusuke*; et al.
Physical Review Research (Internet), 6(2), p.023101_1 - 023101_18, 2024/04
It is generally known that irradiating a solid surface with a laser pulse of ultra-relativistic intensity generates a plasma on the surface, which in turn creates an ultrahigh pressure inside. In this study, the crystal structure analysis of high-pressure phases generated inside silicon single-crystals irradiated by this laser was performed using the diffraction system at the Stress and Imaging apparatus of BL22XU, which is a JAEA-BL. The results obtained confirm the existence of high-pressure phases that silicon is said to possess: body-centered, rhombohedral, hexagonal, and tetragonal phases in the interior. We can get the results that the crystal structure of silicon polymorphs of being include body-centered, rhombohedral, hexagonal-diamond, tetragonal exists. In the future, we will accumulate data and apply them to control the internal structure, strength, and functionality of materials.
Yamamoto, Kazami; Kinsho, Michikazu; Hayashi, Naoki; Saha, P. K.; Tamura, Fumihiko; Yamamoto, Masanobu; Tani, Norio; Takayanagi, Tomohiro; Kamiya, Junichiro; Shobuda, Yoshihiro; et al.
Journal of Nuclear Science and Technology, 59(9), p.1174 - 1205, 2022/09
Times Cited Count：7 Percentile：72.25(Nuclear Science & Technology)In the Japan Proton Accelerator Research Complex, the purpose of the 3 GeV rapid cycling synchrotron (RCS) is to accelerate a 1 MW, high-intensity proton beam. To achieve beam operation at a repetition rate of 25 Hz at high intensities, the RCS was elaborately designed. After starting the RCS operation, we carefully verified the validity of its design and made certain improvements to establish a reliable operation at higher power as possible. Consequently, we demonstrated beam operation at a high power, namely, 1 MW. We then summarized the design, actual performance, and improvements of the RCS to achieve a 1 MW beam.
Shobuda, Yoshihiro; Saha, P. K.; Hotchi, Hideaki; Harada, Hiroyuki; Takayanagi, Tomohiro; Tamura, Fumihiko; Tani, Norio; Togashi, Tomohito; Toyama, Takeshi*; Watanabe, Yasuhiro; et al.
Proceedings of 8th International Particle Accelerator Conference (IPAC '17) (Internet), p.2946 - 2949, 2017/05
no abstracts in English
Hayashi, Naoki; Harada, Hiroyuki; Horino, Koki; Hotchi, Hideaki; Kamiya, Junichiro; Kinsho, Michikazu; Saha, P. K.; Shobuda, Yoshihiro; Takayanagi, Tomohiro; Tani, Norio; et al.
Proceedings of 4th International Particle Accelerator Conference (IPAC '13) (Internet), p.3833 - 3835, 2014/07
no abstracts in English
Saha, P. K.; Harada, Hiroyuki; Hayashi, Naoki; Horino, Koki; Hotchi, Hideaki; Kinsho, Michikazu; Takayanagi, Tomohiro; Tani, Norio; Togashi, Tomohito; Ueno, Tomoaki; et al.
Physical Review Special Topics; Accelerators and Beams, 16(12), p.120102_1 - 120102_11, 2013/12
Times Cited Count：4 Percentile：32.18(Physics, Nuclear)Takayanagi, Tomohiro; Ueno, Tomoaki; Togashi, Tomohito; Harada, Hiroyuki*; Saha, P. K.; Hotchi, Hideaki; Kinsho, Michikazu; Kamiya, Junichiro; Watanabe, Masao; Yoshimoto, Masahiro; et al.
Proceedings of 2009 Particle Accelerator Conference (PAC '09) (DVD-ROM), p.1507 - 1509, 2009/05
The shift bump-magnets, which give a constant bump field in a horizontal plane during injection, comprise four magnets connected in series. However, the total integrated magnetic field over the four magnets is not zero because of the magnetic field interferences with the neighboring quadrupole magnets. So the gap of each magnet was adjusted by inserting thin insulators into the splitting plane of the side yoke so that the field integration becomes zero. The closed orbit distortion due to the field imbalances was then confirmed to be less than 1 mm. Another four paint bump-magnets are connected to their own power supplies, separately. The excitation of each magnet is calibrated by using the beam so that the created bump orbit satisfies the position and inclination at the injection point, and there are no orbit distortions outside the injection area.
Suemitsu, Maki*; Yamamoto, Yoshihisa*; Togashi, Hideaki*; Enta, Yoshiharu*; Yoshigoe, Akitaka; Teraoka, Yuden
Journal of Vacuum Science and Technology B, 27(1), p.547 - 550, 2009/02
Times Cited Count：4 Percentile：29.43(Engineering, Electrical & Electronic)Initial oxidation processes of the Si(110) surface and the chemical bonding states of silicon atoms in the initial oxides have been investigated by using real-time synchrotron-radiation photoemission spectroscopy. Time evolutions of the Si
(
=1-4) components in the Si 2
spectrum indicates that the Si
component always overwhelms the Si
component during the oxidation up to one monolayer. This is in sharp contrast to the Si(001) surface where Si is always larger than Si. The dominance of the Si component is related to presence of two types of bonds on the Si(110) surface and to their possible different reactivity against insertion of oxygen atoms.
2 surfaceYamamoto, Yoshihisa*; Togashi, Hideaki*; Kato, Atsushi*; Takahashi, Yuya*; Konno, Atsushi*; Teraoka, Yuden; Yoshigoe, Akitaka; Asaoka, Hidehito; Suemitsu, Maki*
Applied Surface Science, 254(19), p.6232 - 6234, 2008/07
Times Cited Count：4 Percentile：21.05(Chemistry, Physical)The room temperature adsorbed state of oxygen molecules on Si(110)-162 surface and the structural change after a mild annealing has been investigated by synchrotron radiation photoemission spectroscopy. As a result, despite the very small dosage of oxygen, Si
and Si components already appear in addition to Si
. This is likely to be caused by a selective adsorption of O
molecules into the vicinity of already oxidized sites. After annealing, we found that binding energy of Si and Si increase and approach to their corresponding peak positions of a thermally-grown oxide, and this increase indicates relaxation of the Si-O bond length and Si-O-Si bond angle of metastable oxygen atoms.
Yamamoto, Yoshihisa*; Togashi, Hideaki*; Konno, Atsushi*; Matsumoto, Mitsutaka*; Kato, Atsushi*; Saito, Eiji*; Suemitsu, Maki*; Teraoka, Yuden; Yoshigoe, Akitaka
Shingaku Giho, 108(80), p.65 - 70, 2008/06
The growth process of thermal oxides on Si(110) surface and the development of their interfacial bonding structures have been investigated by using real-time synchrotron radiation photoemission spectroscopy. As a result, it was clarified that the Si component in the Si 2p core-level spectra is always much higher than that of Si for 0-1 mono-layer (ML) oxides on Si(110) surface. Observations on the time-evolution of the O 1s core-level spectrum indicates that the autocatalytic-reaction model proposed for the Si(001) oxidation can be also applicable to the Si(110) oxidation.
Yamamoto, Yoshihisa*; Togashi, Hideaki*; Kato, Atsushi*; Suemitsu, Maki*; Narita, Yuzuru*; Teraoka, Yuden; Yoshigoe, Akitaka
Materials Research Society Symposium Proceedings, Vol.1074, p.36 - 40, 2008/00
In this study, we have investigated the bonding structure of ultrathin oxide films on Si(110) surface by real-time SR-PES experiments. Experiments were conducted at surface chemistry end-station settled at BL23SU in SPring-8. The oxidation temperature was 813 K and the O pressure was 1.110
Pa. As a result, we found that one of the surface core-level shifts in Si 2p spectrum, related to the 1st and the 2nd layer Si atoms, decreases rapidly, coincident with the rapid initial development of the O1s spectrum. This indicates high reactivity of the Si(110)-162 reconstructed surface with oxygen molecules.
2 surface by scanning tunneling microscopyTogashi, Hideaki*; Takahashi, Yuya*; Kato, Atsushi*; Konno, Atsushi*; Asaoka, Hidehito; Suemitsu, Maki*
Japanese Journal of Applied Physics, Part 1, 46(5B), p.3239 - 3243, 2007/05
Times Cited Count：13 Percentile：46.40(Physics, Applied)On Si(110) surface, the hole mobility is enhanced as compared with that on Si(001) surface. This surface is also to be used in the next-generation three-dimensional devices. We conducted scanning-tunneling-microscopy (STM) observation on the initial oxidation of Si(110)-162 surface. The present result suggests less occurrence of etching under the oxidation condition. There is a possibility to form an abrupt oxide/Si interface on the Si(110) surface.
2 surfaces by O 1s photoemission spectroscopy using synchrotron radiationSuemitsu, Maki*; Kato, Atsushi*; Togashi, Hideaki*; Konno, Atsushi*; Yamamoto, Yoshihisa*; Teraoka, Yuden; Yoshigoe, Akitaka; Narita, Yuzuru*; Enta, Yoshiharu*
Japanese Journal of Applied Physics, Part 1, 46(4B), p.1888 - 1890, 2007/04
Times Cited Count：12 Percentile：44.00(Physics, Applied)Initial oxidation of Si(110) surface has been investigated by using real-time X-ray photoemission spectroscopy. The time evolution of the O 1s spectrum shows occurrence of rapid oxidation just after the introduction of the oxygen molecules, which is evidenced by the considerable peak intensity corresponding to oxygen exposure of as low as 1.5L (1L=1.3310
Pa s). This initial oxide is dominated by a state with a relatively low binding energy, which is gradually replaced by a state with a relatively high binding energy with the increase of the oxygen exposure, resulting in the low-KE shift of the O 1s peak. Comparison with previously reported O 1s spectra from dry-oxidized Si(111) surface suggests oxidation at or around the adatoms of Si(110)-162 clean surface as a likely oxidation state for this low-binding-energy peak.
2Suemitsu, Maki*; Togashi, Hideaki*; Kato, Atsushi*; Takahashi, Yuya*; Konno, Atsushi*; Yamamoto, Yoshihisa*; Teraoka, Yuden; Yoshigoe, Akitaka; Asaoka, Hidehito
Materials Research Society Symposium Proceedings, Vol.996, p.19 - 25, 2007/00
From its high hole mobility, as well as its inevitable usage as an active layer in multi-gated FETs, Si(110) surface is expected to play a crucial role in the next generation CMOS devices. We have investigated the initial oxidation of Si(110) surface by using SR-XPS and STM. Reflecting its atomistic structure of the 162 reconstruction, initial oxidation of Si(110) surface shows a unique behavior which is not observed on other surfaces like (111) and (001).
Suemitsu, Maki*; Kato, Atsushi*; Togashi, Hideaki*; Konno, Atsushi*; Yamamoto, Yoshihisa*; Teraoka, Yuden; Yoshigoe, Akitaka; Narita, Yuzuru*
Shingaku Giho, 106(108), p.61 - 63, 2006/06
no abstracts in English
2 surface by photoemission spectroscopySuemitsu, Maki*; Kato, Atsushi*; Togashi, Hideaki*; Konno, Atsushi*; Yamamoto, Yoshihisa*; Teraoka, Yuden; Yoshigoe, Akitaka; Enta, Yoshiharu*; Narita, Yuzuru*
ECS Transactions, 3(2), p.311 - 316, 2006/00
Initial thermal oxidation of Si(110) surface has been investigated by using real-time X-ray photoemission spectroscopy with synchrotron radiation. The Si(110) initial oxidation is characterized by presence of a rapid oxidation just after the introduction of gaseous oxygen molecules. Peak separation of the O1s photoemission spectra suggests the presence of at least two distinct oxidation sites on the surface, which may reflect the complicated surface structure of the Si(110)-162 reconstruction.
1 studied by scanning tunneling microscopyTogashi, Hideaki*; Asaoka, Hidehito; Yamazaki, Tatsuya; Suemitsu, Maki*
Japanese Journal of Applied Physics, Part 2, 44(45), p.L1377 - L1380, 2005/10
Times Cited Count：3 Percentile：13.55(Physics, Applied)no abstracts in English
1 surfaceTogashi, Hideaki*; Suemitsu, Maki*; Asaoka, Hidehito; Yamazaki, Tatsuya
no journal, ,
no abstracts in English
2 surfaceTogashi, Hideaki*; Takahashi, Yuya*; Kato, Atsushi*; Konno, Atsushi*; Suemitsu, Maki*; Asaoka, Hidehito
no journal, ,
no abstracts in English
2 surfacesYamamoto, Yoshihisa*; Togashi, Hideaki*; Konno, Atsushi*; Kato, Atsushi*; Narita, Yuzuru*; Suemitsu, Maki*; Teraoka, Yuden; Yoshigoe, Akitaka
no journal, ,
no abstracts in English
2 by real-time photoemission spectroscopy, 2Kato, Atsushi*; Togashi, Hideaki*; Yamamoto, Yoshihisa*; Konno, Atsushi*; Narita, Yuzuru*; Suemitsu, Maki*; Teraoka, Yuden; Yoshigoe, Akitaka
no journal, ,
Initial oxidation processes of ultra-thin oxide layers on Si(110)-162 surfaces have not been studied yet. Making clear the chemical reaction mechanisms is, however, important for device fabrication. We observed time evolution of oxide coverage on the Si(110)-162 surface at room temperature. The O1s photoemission spectrum increased with increasing oxygen dose and the peak position shifted to higher binding energy side at oxygen pressure of 1.110 Pa. This peak shift is responsible to two kinds of peak components and their independent time evolutions. Time evolution of each component, behaviour of Si2p spectrum, and thermal stability of the surface reveal that the oxidation of Si(110) surface has different characters in compared with that of Si(100) surface. These facts can be understood on the basis of adatom clusters on the Si(110) surface.
