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Saegusa, Jun; Yanagisawa, Kayo; Hasumi, Atsushi; Shimizu, Takenori; Uchida, Yoshiaki*
Radiation Physics and Chemistry, 137, p.210 - 215, 2017/08
Times Cited Count：1 Percentile：10.62(Chemistry, Physical)Following the Fukushima Daiichi Nuclear Power Plant (NPP) accident, large-scale radiation monitoring and environmental clean-up activities have been conducted throughout the Fukushima region. Outside air temperatures there reach 40
C in summer and -20C in winter, which are beyond the quoted range of many radiation survey instruments. For the purpose, temperature performances of four types of portable Japanese survey instruments which are widely used in Fukushima were experimentally investigated with a temperature-controlled chamber.
Sanada, Yukihisa; Nishizawa, Yukiyasu; Yamada, Tsutomu; Ikeda, Kazutaka*; Matsui, Masashi*; Tsuchida, Kiyofumi; Sato, Yoshiharu; Hirayama, Hirokatsu; Takamura, Yoshihide; Nishihara, Katsuya; et al.
JAEA-Research 2013-049, 129 Pages, 2014/03
JAEA-Research-2013-049.pdf:15.5MB
By the nuclear disaster of Fukushima Daiichi Nuclear Power Plant (NPP), Tokyo Electric Power Company (TEPCO), caused by the East Japan earthquake and the following tsunami occurred on March 11, 2011, a large amount of radioactive materials was released from the NPP. In recent years, technologies for autonomous unmanned helicopters (AUHs) have been developed and applied to natural disasters. In expectation of the application of the AUHs to aerial radiation monitoring, we had developed a remote radiation monitoring system. Then, we measured the radiation level by using unmanned helicopter in soil contaminated areas by radioactive cesium emitted from the NPP to evaluate ambient dose-rate distribution around the areas and to investigate the decontamination effect by the measurements before and after decontamination treatment. Here, we reports on the measurement technique and the result.
Shikaze, Yoshiaki; Tanimura, Yoshihiko; Saegusa, Jun; Tsutsumi, Masahiro; Uchida, Yoshiaki*; Yoshizawa, Michio; Harano, Hideki*; Matsumoto, Tetsuro*; Mizuhashi, Kiyoshi
JAEA-Review 2010-065, JAEA Takasaki Annual Report 2009, P. 158, 2011/01
no abstracts in English
Uchida, Yoshiaki*; Suzuki, Katsuaki*; Tamura, Rui*; Ikuma, Naohiko*; Shimono, Satoshi*; Noda, Yohei; Yamauchi, Jun*
Journal of the American Chemical Society, 132(28), p.9746 - 9752, 2010/06
Times Cited Count：51 Percentile：75.43(Chemistry, Multidisciplinary)An anisotropic and inhomogeneous magnetic interaction (the average spin-spin interaction constant, 
0) was observed in the various liquid crystalline (LC) phases of racemic and nonracemic all-organic radical LC compounds. We discussed how the LC superstructures induced the magnetic interaction to operate in the LC phases in terms of spin-spin dipole and exchange interactions by means of VT-EPR spectroscopy. The magnitude of the magnetic interaction depended on the type of LC phase, or the superstructure. Furthermore, these radical LC droplets floating on water were commonly attracted to a permanent magnet and moved freely under the influence of this magnet, whereas the crystallized particles of the same compounds never responded to the magnet. The response of the LC droplets to the magnet also varied depending on the type of LC phase, that is, the extent of the magnetic interaction.
Uchida, Yoshiaki*; Ikuma, Naohiko*; Tamura, Rui*; Shimono, Satoshi*; Noda, Yohei; Yamauchi, Jun*; Aoki, Yoshio*; Nohira, Hiroyuki*
Journal of Materials Chemistry, 18(25), p.2950 - 2952, 2008/07
Times Cited Count：44 Percentile：75.78(Chemistry, Physical)We found out an unusual intermolecular magnetic interaction in the liquid-crystalline (LC) state of an all-organic radical compound on surface of water (73 C); the magnetic interaction actually allows the LC droplet on water to be attracted by a weak permanent magnet, whereas the crystalline phase did not respond to the magnet.
Shikaze, Yoshiaki; Tanimura, Yoshihiko; Saegusa, Jun; Tsutsumi, Masahiro; Yamaguchi, Yasuhiro; Uchida, Yoshiaki*
Radiation Protection Dosimetry, 126(1-4), p.163 - 167, 2007/08
Times Cited Count：3 Percentile：25.51(Environmental Sciences)For neutron energy more than 20 MeV, the international standard of the calibration fields and techniques has not been established. Therefore, by using the quasi-monoenergetic neutron irradiation field of 40-90 MeV at TIARA of JAEA Takasaki, we are developing the calibration field. Here we evaluated the properties of the neutron field, where neutrons were produced in the nuclear reaction of the Li target with 45, 50 and 70 MeV protons. We investigated the neutron beam profile at different distance from the target by using the imaging plates with a polyethylene converter to measure the recoil protons produced in the converter. From the results, properties of the neutron beam profile were found as follows: (1) Irradiation field area was fixed geometrically by the distance from the target and the diameter of the collimator exit; (2) The beam intensity within the irradiation field was in inverse proportion to the square of the distance from the target. Also, we measured the peak energy and energy spectrum of neutron through TOF method by using organic liquid scintillation detector. Then we evaluated the energy spectra of the scattered neutrons at various positions outside the irradiation field through unfolding method. The FORIST unfolding code and the response of SCINFUL-QMD code were used here. From the neutron energy spectra obtained in the different method mentioned above, peak fluence for on-beam position was evaluated comparing with the results in previous evaluation of the neutron field at TIARA.
Kamiyama, Takashi*; Seki, Naoki*; Iwasa, Hirokatsu*; Uchida, Tsutomu*; Ebinuma, Takao*; Narita, Hideo*; Igawa, Naoki; Ishii, Yoshinobu; Bennington, S. M.*; Kiyanagi, Yoshiaki*
Physica B; Condensed Matter, 385-386(1), p.202 - 204, 2006/11
Times Cited Count：7 Percentile：35.12(Physics, Condensed Matter)no abstracts in English
Kato, Tomoko; Suzuki, Yuji*; Makino, Hitoshi; Uchida, Masahiro; Naito, Morimasa; Wakasugi, Keiichiro*; Takahashi, Yoshiaki*
JNC TN1400 2005-024, 14 Pages, 2005/08
JNC-TN1400-2005-024.pdf:0.67MB
Biosphere assessment is positioned as part of an important factor in safety assessment to convert nuclide release rates into surface environment to measures of effect for human, such as radiation dose. In general, a lot of data are handled in the biosphere assessment, and they are based on the feature of specific site. Therefore, it is reasonable to screen parameters in order to manage the limited resource and develop the biosphere assessment effectively. JNC and NUMO established
Uchida, Yoshiaki*; Saegusa, Jun; Kajimoto, Yoichi; Tanimura, Yoshihiko; Shimizu, Shigeru; Yoshizawa, Michio
JAERI-Tech 2005-012, 31 Pages, 2005/03
JAERI-Tech-2005-012.pdf:4.58MB
no abstracts in English
TiShibayama, Tamaki*; Nakamichi, Masaru*; Uchida, Munenori*; Kawamura, Hiroshi; Kinoshita, Hiroshi*; Kiyanagi, Yoshiaki*; Takahashi, Heishichiro*; Nomura, Naoyuki*
JAERI-Conf 2004-006, p.216 - 219, 2004/03
no abstracts in English
Shikaze, Yoshiaki; Tanimura, Yoshihiko; Saegusa, Jun; Tsutsumi, Masahiro; Yamaguchi, Yasuhiro; Uchida, Yoshiaki*
no journal, ,
no abstracts in English
Seki, Naoki*; Kamiyama, Takashi*; Kiyanagi, Yoshiaki*; Iwasa, Hirokatsu*; Hiraga, Fujio*; Uchida, Tsutomu*; Igawa, Naoki; Yamauchi, Hiroki; Ishii, Yoshinobu; Ebinuma, Takao*; et al.
no journal, ,
no abstracts in English
Noda, Yohei; Koizumi, Satoshi; Hashimoto, Takeji; Shimono, Satoshi*; Baba, Masaaki*; Yamauchi, Jun*; Ikuma, Naohiko*; Uchida, Yoshiaki*; Tamura, Rui*; Iima, Yoshio*
no journal, ,
Recently, the chiral paramagnetic liquid crystals (LCs) were synthesized, whose spin sources are fixed in their rigid core. Their responses to an electric and magnetic fields are attractive topics. In general, LC molecules align with the rubbing direction on the oriented film of the LC cell. By far, by use of this surface stabilization effect on LC cell surface, we have developed this potential method of the EPR measurement with rotating the oriented LC cell sample. More recently, the chiral paramagnetic LC showing ferroelectricity was synthesized. We will report the EPR investigation of the orientation change of the ferroelectric LC in response to the switching of an applied electric field. It was shown by the EPR measurement that with no electric field, the LC molecules directed nearly uniformly along the rubbing direction on the cell surface, on the other hand, with electric field (24V), the LC molecules largely tilted from the normal line of the smectic layer.
Matsuoka, Toshiyuki; Yamanaka, Yoshiaki; Asamori, Koichi; Amano, Kenji; Niizato, Tadafumi; Ota, Kunio; Shigeta, Naotaka; Marui, Atsunao*; Uchida, Toshihiro*
no journal, ,
no abstracts in English
Onuki, Shun*; Shinohara, Yoshiaki*; Sutrisna, F.*; Utsumi, Michiaki*; Uchida, Hirohisa*; Matsumura, Yoshihito*; Abe, Hiroshi
no journal, ,
The ion irradiation treatment improved the hydrogen absorption rate. The irradiation of electron beam to the LaNi
Al
hydrogen storage alloy surface was performed bye the dose of 1 
10
e
/cm
, at 1 MeV and 2 MeV of acceleration energy, in vacuum at 2 Pa and atmospheric pressure in air. Electron beam irradiated sample was found to induce a higher absorption rate than that of the un-irradiated one. The maximum value of the hydrogen absorption rate was obtained in the sample irradiated by 2 MeV electron beam in the vacuum condition. X-ray Photoelectron Spectra (XPS) of the samples indicate that composition of oxide layer by electron beam irradiation. The electron beam irradiation was found as an effective way to enhance the rate of the initial activation of the hydrogen absorption of La-Ni alloy.
Shikaze, Yoshiaki; Tanimura, Yoshihiko; Saegusa, Jun; Tsutsumi, Masahiro; Uchida, Yoshiaki*; Yoshizawa, Michio; Harano, Hideki*; Matsumoto, Tetsuro*; Mizuhashi, Kiyoshi
no journal, ,
no abstracts in English
Yoneda, Yasuhiro; Nishihata, Yasuo; Abe, Hiroshi; Uchida, Hirohisa*; Matsumura, Yoshihito*; Takeuchi, Mitsuaki*; Tanakamaru, Tempei*; Shinohara, Yoshiaki*
no journal, ,
The material group that is called smart materials of ferroelectrics, magneto-strictive materials, shape-memory alloys, and hydrogen-storage materials can control physical properties by the elastic strain caused in the crystal. Because the irradiation by the ion beam and the electron beam can efficiently change the elastic strain in the crystal, it is efficient measures to the characteristic modification of a smart material. In this study group, pair-distribution function (PDF) was applied as an new visualization techniques of the crystallographic structure of the irradiation material. It examined whether the irradiation effect of smart materials was extractive by the PDF analysis.
NiSe
, 4Tsuchida, Shun*; Hirose, Yusuke*; Sekikawa, Takuya; Ono, Yoshiaki*; Settai, Rikio*
no journal, ,
Exciton insulators have the property that the entire crystal becomes an insulator due to the collective behavior of electrons and holes bound together in the crystal, and they are beginning to attract attention as a new physical property. In this study, we focused on TaNiSe, which is one of the excitonic insulator candidates, but its synthesis itself is difficult and its physical properties have not yet been clarified. Furthermore, when titanium is substituted for tantalum (M = Ti), the electrical resistivity of the sample with composition ratio x less than 0.06 is semiconducting, while the electrical resistivity of the high-temperature phase behaves metallic when x = 0.06 or higher. The phase transition shown in this study may be a new insight into the realization of excitonic insulators.
NiSe
Tsuchida, Shun*; Hirose, Yusuke*; Sekikawa, Takuya; Ono, Yoshiaki*; Settai, Rikio*
no journal, ,
Excitonic insulators have the property that the entire crystal becomes an insulator due to the collective behavior of electrons and holes bound together in the crystal, and they have begun to attract attention as a new physical property. In this study, we focused on TaNiSe, which is one of the excitonic insulator candidates, but its synthesis itself is difficult and its physical properties have not yet been clarified. The electrical resistivity of M=Ti, Zr, and Hf at low temperatures is 5 to 6 orders of magnitude lower than that of the parent material. Furthermore, when titanium is substituted for tantalum (M=Ti), the electrical resistivity of samples with composition ratio x less than 0.06 is semiconducting, while the electrical resistivity of the high temperature phase behaves metallic when x = 0.06 or higher. The phase transition shown in this study may be a new insight into the realization of excitonic insulators.
NiSe, 5Tsuchida, Shun*; Hirose, Yusuke*; Sekikawa, Takuya; Ono, Yoshiaki*; Settai, Rikio*
no journal, ,
Exciton insulators have the property that the entire crystal becomes an insulator due to the collective behavior of electrons and holes bound together in the crystal, and are attracting attention as a novel physical property. In this study, we succeeded in growing an element-substituted sample (Ta1-xMx)NiSe (M=Ti, Zr, Hf) and found that the electrical resistivity of the high-temperature phase of the sample with a Ti content of 0.06 or more exhibits a metallic behavior. The electrical resistivity of the high-temperature phase behaves metallurgically for samples with a titanium (Ti) content of 0.06 or more. This is in contrast to the pressure effect, which changes from an insulator to a metallic phase discontinuously. Therefore, we also report the results of the electrical resistivity measurement under pressure of (Ta1-xTix)NiSe, in which the element substitution effect and the pressure effect exist simultaneously. The phase transition shown in this study is a new insight into the realization of excitonic insulators.
