Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
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：6 Percentile：84.97(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.
Shimada, Hiroyuki*; Minami, Hirotake*; Okuizumi, Naoto*; Sakuma, Ichiro*; Ukai, Masatoshi*; Fujii, Kentaro; Yokoya, Akinari; Fukuda, Yoshihiro*; Saito, Yuji
Journal of Chemical Physics, 142(17), p.175102_1 - 175102_9, 2015/05
Times Cited Count：10 Percentile：38.6(Chemistry, Physical)Yamaoka, Shingo; Shimizu, Yuka*; Fukuda, Yoshihiro*; Shobu, Takahisa; Konishi, Hiroyuki
JAEA-Technology 2014-027, 21 Pages, 2014/08
JAEA-Technology-2014-027.pdf:28.95MB
At SPring-8 synchrotron radiation beamlines, it is essential to maintain a vacuum between the radiation source and the experimental station. This is achieved by using scroll pumps and turbo molecular pumps. However, scroll pump malfunctions have been reported at BL22XU. Since many of the pumps are located inside radiation-shielding hutches, malfunctions often go un-noticed. As a result, operations can continue despite the malfunction. To facilitate the early detection of scroll pump malfunctions, we have developed a "scroll pump operating status monitoring system (SCP-MS)". The system simultaneously measures motor current and vacuum pressure at the scroll pump. It is possible to monitor pumps from outside of the shielding hutch, something which was not possible until now. The (SCP-MS) has been installed to monitor scroll pumps in actual operation, to monitor the change of the motor current value and vacuum pressure. We report on the detail of the system.
Shimada, Hiroyuki*; Fukao, Taishi*; Minami, Hirotake*; Ukai, Masatoshi*; Fujii, Kentaro; Yokoya, Akinari; Fukuda, Yoshihiro*; Saito, Yuji
Journal of Chemical Physics, 141(5), p.055102_1 - 055102_8, 2014/08
Times Cited Count：16 Percentile：53.96(Chemistry, Physical)Shimada, Hiroyuki*; Fukao, Taishi*; Minami, Hirotake*; Ukai, Masatoshi*; Fujii, Kentaro; Yokoya, Akinari; Fukuda, Yoshihiro*; Saito, Yuji
Chemical Physics Letters, 591, p.137 - 141, 2014/01
Times Cited Count：9 Percentile：33.36(Chemistry, Physical)
-shell ionization by measuring X-ray absorption near edge structureFujii, Kentaro; Fukuda, Yoshihiro; Yokoya, Akinari
International Journal of Radiation Biology, 88(12), p.888 - 894, 2012/12
Times Cited Count：3 Percentile：24.98(Biology)Oka, Toshitaka; Yokoya, Akinari; Fujii, Kentaro; Fukuda, Yoshihiro; Ukai, Masatoshi*
Physical Review Letters, 109(21), p.213001_1 - 213001_5, 2012/11
Times Cited Count：12 Percentile：59.74(Physics, Multidisciplinary)no abstracts in English
Saito, Yuji; Fukuda, Yoshihiro; Takeda, Yukiharu; Yamagami, Hiroshi; Takahashi, Sunao*; Asano, Yoshihiro*; Hara, Toru*; Shirasawa, Katsutoshi*; Takeuchi, Masao*; Tanaka, Takashi*; et al.
Journal of Synchrotron Radiation, 19(3), p.388 - 393, 2012/05
Times Cited Count：101 Percentile：97.06(Instruments & Instrumentation)The soft X-ray beamline BL23SU at SPring-8 has undergone an upgrade with a twin-helical undulator of in-vacuum type to enhance the experimental capabilities of the end stations. The new light source with a fast helicity-switching operation allows not only the data throughput but also the sensitivity in X-ray magnetic circular dichroism (XMCD) to be improved. The operational performance and potential are described by presenting XMCD results of paramagnetic 
-US
measured with a 10 T superconducting magnet.
Yokoya, Akinari; Fujii, Kentaro; Fukuda, Yoshihiro; Ukai, Masatoshi*
Radiation Physics and Chemistry, 78(12), p.1211 - 1215, 2009/12
Times Cited Count：5 Percentile：35.97(Chemistry, Physical)To obtain detailed insights into the physicochemical mechanism of DNA damage induction, "in situ" measurement of electron paramagnetic resonance (EPR) signal from DNA constituent nucleobases, guanine and adenine, has been performed in a vacuum using monochromatic synchrotron soft X-rays. We found that short-lived unpaired electron species arise only during irradiation to the evaporated thin film on a surface. The EPR spectrum of the short-lived species significantly depends on the photon energy irradiated, and the spin concentration obtained from the EPR spectra shows a similar fine structure to the X-ray photoabsorption spectra. For the adenine sample, the spin concentration alters strikingly by water absorption on the sample surface. Trapping of photo- or Auger electrons into a newly generated potential in the nucleobases as the consequence of photoelectric effect is suggested as mechanisms of the induction of the short-lived species.
Kiriyama, Koji; Mitsui, Takaya; Fukuda, Yoshihiro
JAEA-Technology 2009-035, 24 Pages, 2009/07
JAEA-Technology-2009-035.pdf:4.07MB
Single crystal for experiment using by synchrotron radiation X-ray is needed to have high quality and performance as optics element. Therefore, quantitative estimation of performance of the single crystal must be done before the experiment. Precise X-ray optics system has been developed at JAEA/Quantum Beam Science Directorate/Synchrotron Radiation Unit at SPring-8. This system can measure small sample that is less than 0.01 mm in size, and have resolving ability of sample rotation that is less than 0.01 degree. And, scanning of sample, it is possible to measure distribution of quality at sample surface. For example, single crystal of FeBO
which was measured by this system have been installed in synchrotron radiation M
ssbauer spectroscopy using Doppler-shifted 14.4 keV single line 
Fe-Mssbauer radiation.
Fukuda, Yoshihiro; Takeda, Yukiharu; Okane, Tetsuo; Saito, Yuji; Kobayashi, Keisuke*
JAEA-Technology 2007-007, 23 Pages, 2007/03
JAEA-Technology-2007-007.pdf:16.03MB
We have introduced a "Nonstop absorption measurement system" into the XMCD station of BL23SU at SPring-8. This system allows us to shorten the measuring time by about 1/10 in comparison to conventional one. We report on the detail of the system.
Fukuda, Yoshihiro; Saito, Yuji; Yokoya, Akinari; Teraoka, Yuden
JAEA-Technology 2007-002, 35 Pages, 2007/03
JAEA-Technology-2007-002.pdf:3.89MB
JAEA(Japan Atomic Energy Agency) have newly introduced refocusing toroidal mirrors to upgrade a surface chemistry and biophysical spectroscopy stations of BL23SU (JAEA Actinide Science) in SPring-8. We demonstrate significant improvements in the efficiency of experiments. We report on the detail of the systems.
Takeda, Yukiharu; Okane, Tetsuo; Saito, Yuji; Fukuda, Yoshihiro; Yamagami, Hiroshi
no journal, ,
no abstracts in English
Yokoya, Akinari; Fujii, Kentaro; Fukuda, Yoshihiro; Ukai, Masatoshi*
no journal, ,
In order to clarify the photoelectric effect of nitrogen and oxygen atom on DNA damage induction and succeeding mutation induction, unpaired electron species produced in DNA and nucleobases have been studied using an electron paramagnetic resonance (EPR) spectrometer. Thin films of calf thymus DNA and evaporated thymine and cytosine bases were irradiated in the EPR cavity installed in vacuum chamber connected to a soft X-ray beamline in SPring-8 (BL23SU) with synchrotron soft X-rays around nitrogen and oxygen K-edge. Short-lived EPR signals were observed only during irradiation. The photon energy dependences of the yield of these short-lived species arising in nucleobase films are very similar to those of fine structure of photoabsorption spectra (XANES), though that for DNA film is different from XANES of DNA. The origin of these short-lived species will be discussed.
Takeda, Yukiharu; Fukuda, Yoshihiro; Okane, Tetsuo; Saito, Yuji; Kobayashi, Keisuke*; Yamagami, Hiroshi
no journal, ,
no abstracts in English
Oka, Toshitaka; Yokoya, Akinari; Fujii, Kentaro; Fukuda, Yoshihiro; Ukai, Masatoshi*
no journal, ,
In order to clarify the physicochemical mechanism of DNA damage induction due to the excitation/ionization of inner-shell electron in DNA constituent atoms, we have developed an X-band EPR spectrometer system at a synchrotron soft X-ray beamline (BL23SU) in SPring-8. In the present work, we obtained the "in situ" EPR spectra of thymine, cytosine and DNA in XANES regions around K-edge of oxygen and nitrogen during the soft X-ray irradiation. The soft X-ray energy dependence of the spin concentration of nucleobase films show similar fine structures to the XANES spectra. However, the short-lived EPR signal intensity of the DNA significantly increases above the oxygen K-shell ionizing threshold energy. These results suggest that the induction processes of the unpaired electron are different for a DNA molecule and particular nucleobases. The hydrated water which strongly bond to the DNA exists even in vacuum may be plays an important role in the induction of unpaired electron.
Oka, Toshitaka; Yokoya, Akinari; Fukuda, Yoshihiro; Fujii, Kentaro
no journal, ,
no abstracts in English
Saito, Yuji; Fukuda, Yoshihiro; Takeda, Yukiharu; Hara, Toru*; Shirasawa, Katsutoshi*; Takeuchi, Masao*; Kitamura, Hideo*
no journal, ,
The SPring-8 BL23SU (JAEA Actinide Science beamline) has been upgraded by the replacement of the original APPLE-2 type undulator with a twin helical undulator using in-vacuum devices. Recently, polarization switching between beams of opposite helicity at 1 Hz has reached operational status. The test results clearly show that the new light source is very well suited for the measurement of precision X-ray absorption, magnetic circular dichroism, spectra, as well as element-specifc hysteresis loops.
Oka, Toshitaka; Yokoya, Akinari; Fukuda, Yoshihiro; Fujii, Kentaro
no journal, ,
no abstracts in English
Fujii, Kentaro; Kobayashi, Eiichi*; Sugaya, Yuki*; Oka, Toshitaka; Fukuda, Yoshihiro; Yokoya, Akinari; Okajima, Toshihiro*
no journal, ,
no abstracts in English
