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and P
of alkali atomsItakura, Ryuji
no journal, ,
We propose a method for measuring the spectral phase of attosecond pulses by means of angle-resolved photoelectron spectroscopy of alkali atoms in the 2P state. A coherent superposition of 
P and P allows us to observe the quantum beat, whose phase offset is measured as a function of photoelectron energy. The formulation derived in this study elucidates that the phase offset is straightforwardly utilized for measuring the spectral phase of attosecond laser pulses.
Sasaki, Akira; Sunahara, Atsushi*; Nishihara, Katsunobu*; Nishikawa, Takeshi*; Koike, Fumihiro*; Tanuma, Hajime*
no journal, ,
no abstracts in English
Tanimura, Yoshihiko; Saegusa, Jun; Yoshizawa, Michio
no journal, ,
no abstracts in English
Onoda, Shinobu; Hirao, Toshio; Hishiki, Shigeomi; Oshima, Takeshi
no journal, ,
no abstracts in English
Iwamoto, Naoya; Onoda, Shinobu; Hishiki, Shigeomi; Oshima, Takeshi; Murakami, Makoto*; Nakano, Itsuo*; Kawano, Katsuyasu*
no journal, ,
no abstracts in English
Ozu, Akira; Esaka, Fumitaka
no journal, ,
The phase contrast microscopy method is widely used for the measurement of indoor asbestos particles as a standard and conventional technique. However, it is still pointed out that accuracy of the measurement is insufficient because of the difficulty of visual discrimination of asbestos particles from other particles on the microscope. Therefore, we have developed a novel method to discriminate asbestos particles from the other particles by using laser-induced fluorescence spectroscopy. When ultra-violet (266 nm) laser light was applied to asbestos (chrysotile) and the other substance (rock-wool, plaster, etc.), broad fluorescence spectrums over the wavelength range 350 to 700 nm were observed from all substances including the asbestos. It was found that the fluorescence intensity of the other substance at 400-450 nm relative to that at 500 nm differs from that of asbestos. This method is expected to be available for the discrimination of asbestos on the several measurement techniques.
Yamauchi, Toshihiko; Nakagaki, Keita; Kanno, Yoshinori*; Kobayashi, Seiji*; Takemoto, Ryo*
no journal, ,
no abstracts in English
Morioka, Chiharu*; Sugimoto, Hiroki*; Sato, Shinichiro; Imaizumi, Mitsuru*; Oshima, Takeshi; Tajima, Michio*; Kibe, Koichi*
no journal, ,
no abstracts in English
2 surface and surface reconstructionTogashi, Hideaki*; Yamamoto, Yoshihisa*; Goto, Seiichi*; Takahashi, Yuya*; Nakano, Takuya*; Konno, Atsushi*; Suemitsu, Maki*; Asaoka, Hidehito; Yoshigoe, Akitaka; Teraoka, Yuden
no journal, ,
Initial oxidaion processes at Si(110)-162 clean surface with O
mokecules have been observed by real-time SR-XPS and STM methods. SR-XPS experiments were performed at BL23SU in SPring-8 and STM experiments were performed in JAEA Tokai research center. From comparison of oxygen uptake curves of Si(110)-162 with Si(001)-21, following conclusions were obtained. Rapid initial oxidation occured at the Si(110) surface and layer-by-layer oxidation was also took place. In-situ observation with STM revealed that the rapid initial oxidation was due to oxygen adsorption at pentagon-pair Si atoms on the topmost surface, at least 4 kinds of oxygen-adsorbed states, and the DD site was a condensed oxidation state.
2 and autocatalytic reaction modelYamamoto, Yoshihisa*; Togashi, Hideaki*; Konno, Atsushi*; Kato, Atsushi*; Suemitsu, Maki*; Teraoka, Yuden; Yoshigoe, Akitaka
no journal, ,
Ultra-thin oxide film formation processes at Si(110) surface have been studied via real-time photoemission spectroscopy with synchrotron radiation. Oxygen uptake curves were measured using integrated intensity of O1s photoemission peak. Information on oxidation schemes was obtained on the basis of the temperature dependence of the oxygen uptake curves. At oxygen pressure of 1.010
Pa, Langmuir type uptake curve was observed at 870 K whereas a sigmoidal curve was observed at 920 K. We concluded from analogies of Si(001) oxidation that randum adsorption took place at 870 K and two-demensional oxide island formation occured at 920 K.
pressure dependence of interfacial oxidation rateOgawa, Shuichi*; Yoshigoe, Akitaka; Ishizuka, Shinji*; Teraoka, Yuden; Takakuwa, Yuji*
no journal, ,
In this study, real-time XPS was applied to investigating the effect of the rapid O pressure increase on the interfacial oxidation rate in connection with the changes in stress (strain) at the SiO/Si(001) interface. The oxidation experiments were performed using the surface reaction analysis apparatus placed at the BL23SU of SPring-8. The photoelectron spectroscopy measurement of O1s and Si2p was performed during oxidation of a p-type Si(001) surface. When the Si surface was completely covered by the oxide, the O pressure was increased to enhance the interfacial oxidation. The O pressure and initial rate of interfacial reaction after O pressure increase shows the linear correlation and its gradient is obtained as 0.5. It is found that the O supply is not the limiting reaction of SiO/Si interface oxidation. Based on these results, an interfacial reaction model of oxygen and Si atoms is proposed.
N
film by SR-XPSHosoi, Takuji*; Kutsuki, Katsuhiro*; Okamoto, Gaku*; Harada, Makoto*; Yoshigoe, Akitaka; Teraoka, Yuden; Shimura, Takayoshi*; Watanabe, Heiji*
no journal, ,
After wet cleaning of p-Ge(001) by HF solution, the surface was anealed in an ultra-high vacuum and was nitrided using a large area nitrogen plasma apparatus in the conditions of surface temperature: 623 K, RF power: 50 W, nitrogen pressure:10.5 Torr, and reaction period: 30 min. The chemical bonding states and thermal decomposition processes of the nitide film was in-situ analyzed by synchrotron radiation photoemission spectroscopy. XPS spectra of clean Ge surface showed binding energies of Ge3d5/2 and 3/2 levels were 29.2 eV and 29.8 eV, respectively. The Ge surface nitrided by the high density plasma was oxidized by exposure to the air so that both components of nitride and oxide were observed by the SR-XPS before thermal anealing. GeO component was selectively removed by thermal anealing up to 773 K in the UHV condition. After that XPS spectra of pure GeN film could be observed. We concluded chemical shift of the nitrided Ge was 2.2 eV.
Sato, Shinichiro; Miyamoto, Haruki; Imaizumi, Mitsuru*; Shimazaki, Kazunori*; Morioka, Chiharu*; Kawano, Katsuyasu*; Oshima, Takeshi
no journal, ,
no abstracts in English
Kotaki, Hideyuki; Kando, Masaki; Daito, Izuru; Homma, Takayuki; Kameshima, Takashi; Kawase, Keigo; Chen, L.-M.; Fukuda, Yuji; Kiriyama, Hiromitsu; Kondo, Shuji; et al.
no journal, ,
no abstracts in English
Furukawa, Yusuke*; Murakami, Hidetoshi*; Saito, Shigeki*; Sarukura, Nobuhiko*; Nishimura, Hiroaki*; Mima, Kunioki*; Tanaka, Momoko; Nishikino, Masaharu; Yamatani, Hiroshi; Nagashima, Keisuke; et al.
no journal, ,
Zinc oxide (ZnO) has previously been reported to be a potential light-emitting diode materia. We measured the time-resolved emission spectrum of a ZnO crystal for extreme ultraviolet (EUV) laser excitation at 13.9 nm wavelength and compared with UV excitation case. The emission lifetime was determined to be 2.6 ns. This value was not changed even for ultraviolet laser excitation. In the context of the nanosecond regime in the EUV region, ZnO crystal promises to be a feasible scintillation material.
-ray irradiated N-channel 6H-SiC MOSFETsHishiki, Shigeomi; Iwamoto, Naoya; Oshima, Takeshi; Ito, Hisayoshi; Kojima, Kazutoshi*; Kawano, Katsuyasu*
no journal, ,
no abstracts in English
Miyamoto, Haruki; Sato, Shinichiro; Morioka, Chiharu*; Imaizumi, Mitsuru*; Oshima, Takeshi; Kawano, Katsuyasu*
no journal, ,
no abstracts in English
7 at 300KYoshigoe, Akitaka; Teraoka, Yuden
no journal, ,
The time evolution of adsorption states was investigated by O1s and Si2p real-time XPS for oxidation of Si(111)-77 at 300K under the O ambient. Experiments were performed at SUREAC2000 of BL23SU in SPring-8. Pure O gas was controlled to be 5.310
Pa and the O1s and Si2 XPS were measured alternatively by using synchrotron radiation (
670eV,
E200meV). We succeeded in observation of the close correlation of each oxidation states during the oxidation. The initial rates of Si
and ins is much larger than other components. Si
and Si
begin increasing around the dosage of the decrement of paul. The amount of paul is almost half of a maximum value at the decrease of Si and after then the difference of rates between Si and Si appears. The rates of decrement of Si, increment of both Si
and insx2-ad become loose after the disappearance of paul. The Si decreases at increasing insx2-ad again.
Shimojo, Takashi*; Kawai, Hiroaki*; Wakahara, Akihiro*; Okada, Hiroshi*; Sato, Shinichiro; Oshima, Takeshi
no journal, ,
no abstracts in English
-ray sensitivitySakasai, Kaoru; Iwamoto, Yosuke; Soyama, Kazuhiko
no journal, ,
no abstracts in English