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Endo, Shunsuke; Abe, Ryota*; Fujioka, Hiroyuki*; Ino, Takashi*; Iwamoto, Osamu; Iwamoto, Nobuyuki; Kawamura, Shiori*; Kimura, Atsushi; Kitaguchi, Masaaki*; Kobayashi, Ryuju*; et al.
European Physical Journal A, 60(8), p.166_1 - 166_10, 2024/08
Omer, M.; Shizuma, Toshiyuki*; Koizumi, Mitsuo; Taira, Yoshitaka*; Zen, H.*; Ogaki, Hideaki*; Hajima, Ryoichi
UVSOR-50, P. 37, 2023/08
no abstracts in English
Taira, Yoshitaka*; Endo, Shunsuke; Kawamura, Shiori*; Nambu, Taro*; Okuizumi, Mao*; Shizuma, Toshiyuki*; Omer, M.; Zen, H.*; Okano, Yasuaki*; Kitaguchi, Masaaki*
Physical Review A, 107(6), p.063503_1 - 063503_10, 2023/06
Times Cited Count:0 Percentile:0.01(Optics)no abstracts in English
Miyagawa, Reina*; Kamibayashi, Daisuke*; Nakamura, Hirotaka*; Hashida, Masaki*; Zen, H.*; Somekawa, Toshihiro*; Matsuoka, Takeshi*; Ogura, Hiroyuki*; Sagae, Daisuke*; Seto, Yusuke*; et al.
Scientific Reports (Internet), 12, p.20955_1 - 20955_8, 2022/12
Times Cited Count:0 Percentile:0.00(Multidisciplinary Sciences)We evaluated Laser-Induced Periodic Surface Structure (LIPSS) crystal structures using the stress imaging station at BL22XU of JAEA-BL on SPring-8. Crystallization of LIPPS was used different two types laser these are Ti:Sapphire laser (wavelength: 800 nm) and MIR-FEL (mid-infrared free electron laser, wavelength 11.4 m). These lasers are different in the laser pulse structure and the wavelength. We investigated on the effects of formed LIPSS crystallization using different kind of laser. Measured synchrotron X-ray energy is 30 keV and beam size is 20 m. Detector of diffracted X-ray is two-dimensional detector (PILATUS300K, DECTRIS). LIPSS formed using Ti:Sapphire laser has deformed structure with good crystallinity. LIPSS formed using MIR-FEL has dislocation or fault without structural stress. These results show depending on select of laser forming LIPPS structure. These information becomes important a point of the functional application of LIPSS.
Endo, Shunsuke; Shizuma, Toshiyuki*; Zen, H.*; Taira, Yoshitaka*; Omer, M.; Kawamura, Shiori*; Abe, Ryota*; Okudaira, Takuya*; Kitaguchi, Masaaki*; Shimizu, Hirohiko*
UVSOR-49, P. 38, 2022/08
Kajino, Mizuo*; Adachi, Koji*; Igarashi, Yasuhito*; Satou, Yukihiko; Sawada, Morihiro*; Sekiyama, Tsuyoshi*; Zaizen, Yuji*; Saya, Akane*; Tsuruta, Haruo*; Moriguchi, Yuichi*
Journal of Geophysical Research; Atmospheres, 126(1), p.e2020JD033460_1 - e2020JD033460_23, 2021/01
Times Cited Count:12 Percentile:72.30(Meteorology & Atmospheric Sciences)Fujimori, Kosuke*; Kitaura, Mamoru*; Taira, Yoshitaka*; Fujimoto, Masaki*; Zen, H.*; Watanabe, Shinta*; Kamada, Kei*; Okano, Yasuaki*; Kato, Masahiro*; Hosaka, Masahito*; et al.
Applied Physics Express, 13(8), p.085505_1 - 085505_4, 2020/08
Times Cited Count:5 Percentile:31.64(Physics, Applied)To clarify the existence of cation vacancies in Ce-doped GdAlGaO (Ce:GAGG) scintillators, we performed gamma-ray-induced positron annihilation lifetime spectroscopy (GiPALS). GiPAL spectra of GAGG and Ce:GAGG comprised two exponential decay components, which were assigned to positron annihilation at bulk and defect states. By an analogy with Ce:YAlO, the defect-related component was attributed to Al/Ga-O divacancy complexes. This component was weaker for Ce, Mg:GAGG, which correlated with the suppression of shallow electron traps responsible for phosphorescence. Oxygen vacancies were charge compensators for Al/Ga vacancies. The lifetime of the defect-related component was significantly changed by Mg co-doping. This was understood by considering aggregates of Mg ions at Al/Ga sites with oxygen vacancies, which resulted in the formation of vacancy clusters.
Amamoto, Ippei; Kobayashi, Hidekazu; Kitamura, Naoto*; Takebe, Hiromichi*; Mitamura, Naoki*; Tsuzuki, Tatsuya*; Fukayama, Daigen*; Nagano, Yuichi*; Jantzen, T.*; Hack, K.*
Journal of Nuclear Science and Technology, 53(10), p.1467 - 1475, 2016/10
Times Cited Count:4 Percentile:36.03(Nuclear Science & Technology)The iron phosphate glass (IPG) medium is known to be a high-efficiency glass medium, therefore we try to evaluate its applicability to immobilize sludge bearing radioactive nuclides arising from treatment of contaminated water at the stricken Fukushima Daiichi Nuclear Power Plant. For this study, many physical and chemical properties of target materials are necessary to evaluate the behaviours of IPG medium and its waste forms. Inevitably, it will entail the need for many and varied types of experiments to be carried out under high temperature. It is therefore rational to apply appropriate theoretical analysis first so as to reduce the number of experimental run. For this reason, some necessary thermodynamic values for theoretical analysis were estimated by CALPHAD approach followed by making up the calculated phase diagrams. By comparison with experimental results, they were found to be reliable for evaluating the behaviours of IPG medium and its waste forms.
Negm, H.*; Ogaki, Hideaki*; Daito, Izuru*; Hayakawa, Takehito; Zen, H.*; Kii, Toshiteru*; Masuda, Kai*; Hori, Toshitada*; Hajima, Ryoichi; Shizuma, Toshiyuki; et al.
Journal of Nuclear Science and Technology, 52(6), p.811 - 820, 2015/06
Times Cited Count:4 Percentile:32.74(Nuclear Science & Technology)The dependence of the nuclear resonance fluorescence (NRF) yield on the target thickness was studied. To this end, an NRF experiment was performed on U using a laser Compton back-scattering (LCS) -ray beam at the High Intensity -ray Source facility at Duke University.
Hoheisel, R.*; Gonzlez, M.*; Lumb, M.*; Scheiman, D.*; Messenger, S. R.*; Bailey, C. G.*; Lorentzen, J.*; Tibbits, T. N. D.*; Imaizumi, Mitsuru*; Oshima, Takeshi; et al.
IEEE Journal of Photovoltaics, 4(1), p.253 - 259, 2014/01
Times Cited Count:19 Percentile:61.64(Energy & Fuels)Analysis on the radiation response of solar cells with multi quantum wells (MQW) included in the quasi-intrinsic region between the emitter and the base layer is presented. We found that in the case of MQW devices, carrier removal (CR) effects are also observed. Experimental measurements and numerical simulations reveal that with increasing radiation dose, CR can cause the initially quasi-intrinsic background doping of the MQW region to become specifically n- or p-type. This can result in a significant narrowing and even the collapse of the electric field between the emitter and the base where the MQWs are located. The implications of the CR-induced modification of the electric field on the current-voltage characteristics and on the collection efficiency of carriers generated within the emitter, the MQW region, and the base are discussed for different radiation dose conditions. This paper concludes with a discussion of improved radiation hard MQW device designs.
Omer, M.*; Negm, H.*; Ogaki, Hideaki*; Daito, Izuru*; Hayakawa, Takehito; Bakr, M.*; Zen, H.*; Hori, Toshitada*; Kii, Toshiteru*; Masuda, Kai*; et al.
Nuclear Instruments and Methods in Physics Research A, 729, p.102 - 107, 2013/11
Times Cited Count:6 Percentile:43.64(Instruments & Instrumentation)The performance of LaBr (Ce) to measure nuclear resonance fluorescence (NRF) excitations is discussedin terms of limits of detection and in comparison with high-purity germanium (HPGe)detectors near the 2 MeV region where many NRF excitation levels from special nuclear materials are located. The NRF experiment was performed at the High Intensity Gamma-ray Source (HIGS) facility of Duke University. The incident -rays, of 2.12 MeV energy, hit a BC target to excite the B nuclei to the first excitation level. The statistical-sensitive non-linear peak clipping (SNIP) algorithm was implemented to eliminate theback ground and enhance the limits of detection for the spectra measured with LaBr (Ce). Both detection and determination limits were deduced from the experimental data.
Omer, M.*; Negm, H.*; Zen, H.*; Daito, Izuru*; Kii, Toshiteru*; Masuda, Kai*; Ogaki, Hideaki*; Hajima, Ryoichi; Shizuma, Toshiyuki; Hayakawa, Takehito; et al.
Japanese Journal of Applied Physics, 52(10), p.106401_1 - 106401_4, 2013/10
Times Cited Count:7 Percentile:30.49(Physics, Applied)A nuclear resonance fluorescence (NRF) experiment was performed on a U target with quasi-monochromatic -rays at the High Intensity Gamma-ray Source (HIGS) facility of Duke University using a 1733 keV resonant energy. A LaBr (Ce) detector array consisting of eight cylindrical detectors, each with a length of 7.62 cm and a diameter of 3.81 cm, was implemented in this measurement. Moreover, a high-purity germanium (HPGe) detector array consisting of four detectors, each of which has a relative efficiency of 60%, was used as the benchmark for the measurement taken using the LaBr (Ce) detector array. The integrated cross section of the NRF level, measured with LaBr (Ce) detectors, showed good agreement with the available data.
Gonzlez, M.*; Hoheisel, R.*; Lumb, M.*; Scheiman, D.*; Bailey, C. G.*; Lorentzen, J.*; Maximenko, S.*; Messenger, S. R.*; Jenkins, P. P.*; Tibbits, T. N. D.*; et al.
Proceedings of 39th IEEE Photovoltaic Specialists Conference (PVSC-39) (CD-ROM), p.3233 - 3236, 2013/06
The radiation response of multi quantum wall (MQW) triple junction and component cells was analyzed. Initial results show that for 1MeV electron irradiation the middle MQW cell governs the degradation of the triple junction. This is attributed the specific middle cell design, in particular the thick 0.98 m depletion region, and alternative, more radiation hard, designs are presented. Additionally, characterization studies, including dark IV, external quantum efficiency, electroluminescence, as well as defect characterization were investigated.
Bizen, Daisuke*; Nakao, Hironori*; Iwasa, Kazuaki*; Murakami, Yoichi*; Osakabe, Toyotaka; Fujioka, Jun*; Yasue, Toshio*; Miyasaka, Shigeki*; Tokura, Yoshinori*
Journal of the Physical Society of Japan, 81(2), p.024715_1 - 024715_6, 2012/02
Times Cited Count:6 Percentile:42.56(Physics, Multidisciplinary)The magnetic phase diagrams for VO ( = Y, Tb) were determined by low temperature and high pressure neutron-diffraction techniques. We found that the magnetic ground state in TbVO changes from -type spin ordering (-SO) to -type spin ordering (-SO) on application of pressure. The transition of the magnetic ground state also indicates that the ground state of the orbital ordering changes from -type orbital ordering (-OO) to -type orbital ordering (-OO). In YVO, the -SO and -OO phases set in simultaneously up to 6.2 GPa, and the disorder-[-SO, -OO] phase transition appears above 6 GPa. This is the first observation of a simultaneous spin and orbital order-disorder phase transition in perovskite-type transition-metal oxides MO. The [-SO, -OO] phase is strongly stabilized with increasing pressure, and both the covalency effect and the superexchange interaction play roles in this stabilization.
Ishii, Kenji; Ishihara, Sumio*; Murakami, Yoichi*; Ikeuchi, Kazuhiko*; Kuzushita, Kaori*; Inami, Toshiya; Owada, Kenji; Yoshida, Masahiro; Jarrige, I.; Tatami, Naka*; et al.
Physical Review B, 83(24), p.241101_1 - 241101_4, 2011/06
Times Cited Count:21 Percentile:64.19(Materials Science, Multidisciplinary)Sakanaka, Shogo*; Akemoto, Mitsuo*; Aoto, Tomohiro*; Arakawa, Dai*; Asaoka, Seiji*; Enomoto, Atsushi*; Fukuda, Shigeki*; Furukawa, Kazuro*; Furuya, Takaaki*; Haga, Kaiichi*; et al.
Proceedings of 1st International Particle Accelerator Conference (IPAC '10) (Internet), p.2338 - 2340, 2010/05
Future synchrotron light source using a 5-GeV energy recovery linac (ERL) is under proposal by our Japanese collaboration team, and we are conducting R&D efforts for that. We are developing high-brightness DC photocathode guns, two types of cryomodules for both injector and main superconducting (SC) linacs, and 1.3 GHz high CW-power RF sources. We are also constructing the Compact ERL (cERL) for demonstrating the recirculation of low-emittance, high-current beams using above-mentioned critical technologies.
Harris, R. D.*; Imaizumi, Mitsuru*; Walters, R. J.*; Lorentzen, J. R.*; Messenger, S. R.*; Tischler, J. G.*; Oshima, Takeshi; Sato, Shinichiro; Sharps, R. P.*; Fatemi, N. S.*
IEEE Transactions on Nuclear Science, 55(6), p.3502 - 3507, 2008/12
Times Cited Count:8 Percentile:48.77(Engineering, Electrical & Electronic)The performance of triple junction InGaP/GaAs/Ge solar cells have been studied following low temperature irradiation while using low intensity illumination. High energy electron and proton irradiations have been performed with cell characterization carried out in situ at the irradiation temperature with no intermediate temperature changes. As such, these conditions reflect those found for deep space, solar powered missions that are far from the sun. Cell characterization consisted of I-V measurements which permitted the extraction of the four principle solar cell parameters: short circuit current, open circuit voltage, maximum power, and fill factor. In addition, quantum efficiency measurements were made prior to and following the irradiations. The low temperature irradiations were followed by a room temperature anneal to determine if any subsequent recovery was present.
Walters, R. J.*; Harris, R. D.*; Imaizumi, Mitsuru*; Lorentzen, J. R.*; Messenger, S. R.*; Tischler, J. G.*; Oshima, Takeshi; Sato, Shinichiro; Sharps, R. P.*; Fatemi, N. S.*
Proceedings of the 8th International Workshop on Radiation Effects on Semiconductor Devices for Space Applications (RASEDA-8), p.105 - 108, 2008/12
The performance of triple junction InGaP/GaAs/Ge space solar cells was studied following high energy electron irradiation at low temperature. Cell characterization was carried out at the irradiation temperature while using low intensity illumination, and, as such, these conditions reflect those found for deep space, solar powered missions that are far from the sun. Cell characterization consisted of I-V measurements and quantum efficiency measurements. The low temperature irradiations caused substantial degradation that differs in some ways from that seen after room temperature irradiations. The short circuit current degrades more at low temperature while the open circuit voltage degrades more at room temperature. A room temperature anneal after the low temperature irradiation produced a substantial recovery in the degradation.
Jarrige, I.; Cai, Y. Q.*; Ishii, Hirofumi*; Hiraoka, Nozomu*; Bleuzen, A.*
Applied Physics Letters, 93(5), p.054101_1 - 054101_3, 2008/08
Times Cited Count:9 Percentile:36.34(Physics, Applied)Agui, Akane; Yoshigoe, Akitaka; Nakatani, Takeshi*; Matsushita, Tomohiro*; Saito, Yuji; Yokoya, Akinari; Tanaka, Hitoshi*; Miyahara, Yoshikazu*; Shimada, Taihei; Takeuchi, Masao*; et al.
Review of Scientific Instruments, 72(8), p.3191 - 3197, 2001/08
Times Cited Count:21 Percentile:71.54(Instruments & Instrumentation)no abstracts in English