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293 results on '"Yonehara H"'

1. Timing System of SPring-8 Booster Synchrotron

Author

Hosoda, N., Ohshima, T., Aoki, T., Asaka, T., Ego, H., Fukami, K., Kawashima, Y., Ohashi, Y., Takashima, T., and Yonehara, H.

Subjects
Physics - Accelerator Physics
Abstract

The timing system of SPring-8 booster synchrotron generates various timing signals concerning beam injection, acceleration from 1 GeV to 8 GeV and ejection. We have improved the timing system of the synchrotron giving it better stability and flexibility. This improvement results the other merits of advanced operations, for example, storing electron beam in the synchrotron, changing the injection cycle from 1 Hz to the slower frequency to increase the RF knock-out (RF-KO) operation period and ejecting the low energy beam during ramping up., Comment: International Conference on Accelerator and Large Experimental Physics Control Systems San Jose, California, November 27-30, 2001, (TUAP046), 3 pages, PDF genarated by MS-Word2000 on Windows98

Published
2001

4. DC septum magnets and their leakage field effects on an electron beam in the SPring-8 storage ring

Author

Tsumaki, K., Shimada, T., Kajimoto, K., Yonehara, H., and Kumagai, N.

Subjects
Electron beams -- Usage, Superconducting magnets -- Electric properties, Business, Electronics, Electronics and electrical industries
Abstract

A study is conducted to fabricate improved DC septum magnets that have smaller leakage field for continuous beam injection. After reducing the leakage fields, the orbit changes during injection are less than the beam sizes, which satisfied the requirements for continuous beam injection.

Published
2004

9. Natural radiation exposures for cave residents in China

Author

Tokonami, S., primary, Sun, Q., additional, Akiba, S., additional, Ishikawa, T., additional, Furukawa, M., additional, Zhuo, W., additional, Hou, C., additional, Zhang, S., additional, Narazaki, Y., additional, Yonehara, H., additional, and Yamada, Y., additional

Published
2005
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14. The JCO criticality accident at Tokai-mura, Japan: an overview of the sampling campaign and preliminary results

Author

Komura, K, Yamamoto, M, Muroyama, T, Murata, Y, Nakanishi, T, Hoshi, M, Takada, J, Ishikawa, M, Takeoka, S, Kitagawa, K, Suga, S, Endo, S, Tosaki, N, Mitsugashira, T, Hara, M, Hashimoto, T, Takano, M, Yanagawa, Y, Tsuboi, T, Ichimasa, M, Ichimasa, Y, Imura, H, Sasajima, E, Seki, R, Saito, Y, Kondo, M, Kojima, S, Muramatsu, Y, Yoshida, S, Shibata, S, Yonehara, H, Watanabe, Y, Kimura, S, Shiraishi, K, Ban-nai, T, Sahoo, S.K, Igarashi, Y, Aoyama, M, Hirose, K, Uehiro, T, Doi, T, Tanaka, A, and Matsuzawa, T

Published
2000
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16. Distribution of uranium, thorium and some stable trace and toxic elements in human hair and nails in Niska Banja Town, a high natural background radiation area of Serbia (Balkan Region, South-East Europe)

Author

Sahoo, Sarata Kumar, Žunić, Zora S., Kritsananuwat, Rawiwan, Zagrodzki, P., Bossew, Peter, Veselinović, Nenad, Mishra, S., Yonehara, H., Tokonami, S., Sahoo, Sarata Kumar, Žunić, Zora S., Kritsananuwat, Rawiwan, Zagrodzki, P., Bossew, Peter, Veselinović, Nenad, Mishra, S., Yonehara, H., and Tokonami, S.

Abstract

Human hair and nails can be considered as bio-indicators of the public exposure to certain natural radionuclides and other toxic metals over a long period of months or even years. The level of elements in hair and nails usually reflect their levels in other tissues of body. Nigka Banja, a spa town located in southern Serbia, with locally high natural background radiation was selected for the study. To assess public exposure to the trace elements, hair and nail samples were collected and analyzed. The concentrations of uranium, thorium and some trace and toxic elements (Mn, Ni, Cu, Sr, Cd, and Cs) were determined using inductively coupled plasma mass spectrometry (ICP-MS). U and Th concentrations in hair varied from 0.0002 to 0.0771 mu g/g and from 0.0002 to 0.0276 mu g/g, respectively. The concentrations in nails varied from 0.0025 to 0.0447 mu g/g and from 0.0023 to 0.0564 mu/g for U and Th, respectively. We found significant correlations between some elements in hair and nails. Also indications of spatial clustering of high values could be found. However, this phenomenon as well as the large variations in concentrations of heavy metals in hair and nail could not be explained. As hypotheses, we propose possible exposure pathways which may explain the findings, but the current data does not allow testing them. Crown Copyright (C) 2015 Published by Elsevier Ltd. All rights reserved.

Published
2015

34. Effect of radon measurement methods on dose estimation

Author

Kavasi, N., primary, Kobayashi, Y., additional, Kovacs, T., additional, Somlai, J., additional, Jobbagy, V., additional, Nagy, K., additional, Deak, E., additional, Berhes, I., additional, Bender, T., additional, Ishikawa, T., additional, Tokonami, S., additional, Vaupotic, J., additional, Yoshinaga, S., additional, and Yonehara, H., additional

Published
2011
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37. Test Study for Generation of Short Pulsed Synchrotron Radiation by Kicker Magnet in SPring-8 Storage Ring

Author

Mitsuda, C., primary, Fukami, K., additional, Kobayashi, K., additional, Masaki, M., additional, Mochihashi, A., additional, Nakanishi, T., additional, Oishi, M., additional, Schimizu, J., additional, Shimosaki, Y., additional, Shoji, M., additional, Soutome, K., additional, Tamura, K., additional, Yonehara, H., additional, Ohshima, T., additional, Garrett, R., additional, Gentle, I., additional, Nugent, K., additional, and Wilkins, S., additional

Published
2010
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41. NATURAL RADIOACTIVITYAND RADON EXHALATION RATES IN MAN-MADE TILES USEDAS BUILDING MATERIALS IN JAPAN.

Author

Iwaoka, K., Hosoda, M., Suwankot, N., Omori, Y., Ishikawa, T., Yonehara, H., and Tokonami, S.

Subjects
ATMOSPHERIC radon, NATURAL radioactivity, CONSTRUCTION materials, BACKGROUND radiation, RADON, CHEMICAL ecology
Abstract

Man-made tiles frequently used in Japan were collected, and activity concentrations and radon (222Rn) exhalation rates in these tiles were measured. Dose estimations for inhabitants living in houses built using these tiles were also carried out. The activity concentrations of 226Ra, 228Ra and 40K in the man-made tiles were 31-170, 35-110 and 260-980 Bq kg-1, respectively. The 222Rn exhalation rates in the tiles were 8.8-21 µBq m-2 s-1. The ranges of experimental activity concentrations and 222Rn exhalation rates were almost identical to those of natural rocks used as typical building materials in Japan. The maximum value of effective dose to inhabitants living in houses built with the man-made tiles was 0.14 mSv y-1, which is lower than the reference level range (1-20 mSv y-1) for abnormally high levels of natural background radiation published in the ICRP Publication 103. [ABSTRACT FROM AUTHOR]

Published
2015
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46. Test Study for Generation of Short Pulsed Synchrotron Radiation by Kicker Magnet in SPring-8 Storage Ring.

Author

Mitsuda, C., Fukami, K., Kobayashi, K., Masaki, M., Mochihashi, A., Nakanishi, T., Oishi, M., Schimizu, J., Shimosaki, Y., Shoji, M., Soutome, K., Tamura, K., Yonehara, H., and Ohshima, T.

Subjects
PHYSICS experiments, SYNCHROTRON radiation, ELECTRON beams, MAGNETS, X-rays
Abstract

A shorter pulse of synchrotron radiation is desired to measure a fast dynamic process exploration with a better resolution by material structure physics users. Among many complex schemes proposed for this purpose, we tested a simple scheme which makes use of a head-tail oscillation of a circulating electron beam with a small beam emittance. We have developed a new kicker magnet system which generated a short pulsed horizontal field of about 4.19 mT in 1.4 μs pulse width with 1 Hz repetition. With this new developed kicker magnet system, we observed a bunch profile which leaned impressively between head and tail position by a visible light streak camera. Then we succeeded in achieving the shorter X-ray pulse width than the original one after a vertical slit being sliced by ∼6 times. The observed X-ray pulse width was 7.38±2.35 ps in FWHM. [ABSTRACT FROM AUTHOR]

Published
2010
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48. Photonuclear reaction data and γ-ray sources for astrophysics.

Author

Fülöp, Zsolt, Gyürky, György, Somorjai, Endre, Utsunomiya, H., Goko, S., Toyokawa, H., Ohgaki, H., Soutome, K., Yonehara, H., Goriely, S., Mohr, P., and Fülöp, Zs.

Abstract

Direct determination of photoneutron cross sections of astrophysical importance has recently become possible with use of quasi-monochromatic γ beams produced in laser Compton backscattering (LCS) from relativistic electrons at AIST. The astrophysics to be discussed with the photodisintegration cross section are both stellar and big bang nucleosyntheses regarding the production of p-process and s-process nuclei as well as light elements. Synchrotron radiations from a 10 tesla superconducting wiggler (SCW) at SPring-8 serve as an ideal photon source to determine photoreaction rates. This paper covers the latest cross section measurements with the LCS photon beams and a feasibility study of determining (γ,x) (x = n, p, α) reaction rates with the SCW radiation. [ABSTRACT FROM AUTHOR]

Published
2006
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