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Amemiya, Kuniaki*; Nakazawa, Masaharu*; Ariyoshi, Masahiko; Ito, Keisuke
JNC TY9400 2004-008, 52 Pages, 2004/04
A new monitoring system of nuclear reactor plants by means of optical fiber Bragg gratings (FBGs) was developed which have sensitivity in temperature, distortion and vibration. The reflective wavelength of FBGs was not influenced by gamma-ray irradiation up to 1.4MGy and by exposure to fast neutrons in excess of 10 sup14 n/cm sup2. A temperature-insensitive vibration sensing system was constructed and operated with no trouble in gamma-ray environments up to 100kGy. Furthermore, a multiple point vibration sensing system was designed and constructed. The system was successfully demonstrated on a cooling system at the "Yayoi" reactor. Thus, we tried to apply the monitoring system to a primary loop area of JOYO to confirm the applicability of FBG sensors for the commercial power reactors. Although a correlation of sodium flow in side pipes and vibration measured by FBG sensors was found before starting of the reactor, it became impossible after starting operation of the reactor because of a decline of signal amplitude. Investigating the reason, it was mainly caused by significant transmission losses at the splicing point and there were no problems with FBG sensors. Various methods, for example, using a more powerful light source and changing the splicing method, may be used to improve it in the future.
Katagiri, Masaki; Sakasai, Kaoru; Matsubayashi, Masahito; Takahashi, Hiroyuki*; Nakazawa, Masaharu*
Nuclear Instruments and Methods in Physics Research A, 513(1-2), p.374 - 378, 2003/11
Times Cited Count:3 Percentile:27.64(Instruments & Instrumentation)no abstracts in English
Katagiri, Masaki; To, Kentaro; Sakasai, Kaoru; Matsubayashi, Masahito; Birumachi, Atsushi; Takahashi, Hiroyuki*; Nakazawa, Masaharu*
Applied Physics A, 74(Suppl.1), p.S1604 - S1606, 2002/12
Times Cited Count:6 Percentile:28.27(Materials Science, Multidisciplinary)no abstracts in English
To, Kentaro; Katagiri, Masaki; Sakasai, Kaoru; Matsubayashi, Masahito; Birumachi, Atsushi; Takahashi, Hiroyuki*; Nakazawa, Masaharu*
Applied Physics A, 74(Suppl.1), p.S1601 - S1603, 2002/12
Times Cited Count:6 Percentile:28.27(Materials Science, Multidisciplinary)no abstracts in English
Sakasai, Kaoru; Katagiri, Masaki; To, Kentaro; Takahashi, Hiroyuki*; Nakazawa, Masaharu*; Kondo, Yasuhiro*
Applied Physics A, 74(Suppl.1), p.S1589 - S1591, 2002/12
Times Cited Count:30 Percentile:71.74(Materials Science, Multidisciplinary)A phosphor material such as SrBPO:Eu
has been investigated for two-dimensional imaging for pulsed-neutron source. The authors found this phosphor itself shows photostimulated luminescence (PSL) by illumination of 635 nm laser light after neutron irradiation without adding any neutron sensitive materials such as Gd. The PSL intensity per neutron flux was proportional to E
, where E is neutron energy. The neutron sensitivity was increased by using enriched boron instead of natural boron. The S
/S
ratio of this phosphor using enriched boron was better than that of a commercially available imaging plate, where S
and S
are gamma and neutron sensitivities, respectively.
To, Kentaro; Katagiri, Masaki; Sakasai, Kaoru; Matsubayashi, Masahito; Birumachi, Atsushi; Takahashi, Hiroyuki*; Nakazawa, Masaharu*
Nuclear Instruments and Methods in Physics Research A, 485(3), p.571 - 575, 2002/09
Times Cited Count:2 Percentile:18.88(Instruments & Instrumentation)no abstracts in English
Nakazawa, Masaharu*; Takahashi, Hiroyuki*; Fukuda, Daiji*
JAERI-Tech 2002-019, 30 Pages, 2002/03
no abstracts in English
Katagiri, Masaki; Sakasai, Kaoru; Kishimoto, Maki; Nakamura, Tatsuya; To, Kentaro; Takahashi, Hiroyuki*; Nakazawa, Masaharu*
Nuclear Instruments and Methods in Physics Research A, 477(1-3), p.179 - 183, 2002/03
Times Cited Count:4 Percentile:29.31(Instruments & Instrumentation)no abstracts in English
Sakasai, Kaoru; Katagiri, Masaki; Nakamura, Tatsuya; To, Kentaro; Takahashi, Hiroyuki*; Nakazawa, Masaharu*
IEEE Transactions on Nuclear Science, 49(1), p.156 - 159, 2002/02
Times Cited Count:0 Percentile:0.01(Engineering, Electrical & Electronic)no abstracts in English
Kobayashi, Katsuhei*; Iguchi, Tetsuo*; Iwasaki, Shin*; Aoyama, Takafumi*; Shimakawa, Satoshi; Ikeda, Yujiro; Odano, Naoteru; Sakurai, Kiyoshi; Shibata, Keiichi; Nakagawa, Tsuneo; et al.
JAERI 1344, 133 Pages, 2002/01
The JENDL Dosimetry File 99 (JENDL/D-99) has been prepared for determinations of neutron flux/fluence and energy spectrum at specific neutron fields. This file contains data for 67 reactions with 47 nuclides. Cross sections for 33 major dosimetry reactions and their covariance data were simultaneously generated and the other 34 reaction data were mainly adopted from the first version, JENDL/D-91. The GMA code was mainly used for most of the evaluation procedures by referring the basic experimental data in EXFOR. The resultant data are given in the neutron energy region below 20 MeV in both of point-wise and group-wise files in the ENDF-6 format. In order to confirm reliability of the data, several integral tests have been carried out: comparison with the data in IRDF-90V2 and average cross sections measured in fission neutron fields, fast/thermal reactor spectra, DT neutron fields and Li(d,n) neutron fields. The contents of JENDL/D-99 and the results of the integral tests are described in this report. All of the dosimetry cross sections are shown in a graphical form in the Appendix.
Sakasai, Kaoru; Katagiri, Masaki; To, Kentaro; Takahashi, Hiroyuki*; Nakazawa, Masaharu*; Kondo, Yasuhiro*
2002 IEEE Nuclear Science Symposium Conference Record, Vol.1, p.455 - 459, 2002/00
Characteristics of a SrBPO:Eu
material have been investigated as a neutron storage phosphor. The authors found this phosphor shows photostimulated luminescence by illumination with 635 nm laser light after neutron irradiation. The neutron sensitivity was proportional to E
, where E is neutron energy. The S
/S
ratio of the phosphor using enriched boron was better than that of a commercially available imaging plate, where S
/ and S
are the gamma and neutron sensitivities, respectively. A collimated neutron beam image was clearly obtained with the phosphor sample by scanning focused laser light on it.
Katagiri, Masaki; Nakamura, Tatsuya; Okubo, Masataka*; Pressler, H.*; Takahashi, Hiroyuki*; Nakazawa, Masaharu*
AIP Conference Proceedings 605, p.177 - 180, 2002/00
no abstracts in English
Nakamura, Tatsuya; Katagiri, Masaki; Okubo, Masataka*; Pressler, H.*; Takahashi, Hiroyuki*; Nakazawa, Masaharu*
AIP Conference Proceedings 605, p.173 - 176, 2002/00
Periodical distribution of charge output in superconducting tunnel junction (STJ) having a structure of Nb/Al/AlO/Al/Nb with size of 200 x 200
was first observed by Low Temperature Scanning Synchrotron Microscope experiments. Two swelled parts were appeared in the distribution of charge output and the period of the swelled parts was about 100
. It is found that this distribution was occurred under the conditions; (1) the size of the STJ is more than twice of Josephson characteristic length and (2) a bias voltage applied to the device is more than 0.2mV of about the energy gap of the trapping layers. It was confirmed that this anomalous distribution of charge output significantly distorts the shape of the photo peak and degrades the energy resolution of the STJ detector.
Sakasai, Kaoru; Katagiri, Masaki; To, Kentaro; Takahashi, Hiroyuki*; Nakazawa, Masaharu*; Kondo, Yasuhiro*
Denki Gakkai Genshiryoku Kenkyukai Shiryo (NE-01-8), p.41 - 46, 2001/09
A phosphor material such as SrBPO:Eu
has been investigated for two-dimensional imaging for pulsed-neutron source. The authors found this phosphor itself shows photostimulated luminescence (PSL) by illumination of 635 nm laser light after neutron irradiation without adding any neutron sensitive materials such as Gd. The PSL intensity per neutron flux was proportional to E
, where E is neutron energy. The neutron sensitivity was increased by using enriched boron instead of natural boron. The S
/S
ratio of this phosphor using enriched boron was better than that of a commercially available imaging plate, where S
and S
are gamma and neutron sensitivities, respectively.
Sakasai, Kaoru; Katagiri, Masaki; To, Kentaro; Nakamura, Tatsuya; Takahashi, Hiroyuki*; Nakazawa, Masaharu*
Journal of the Physical Society of Japan, Vol.70, Supplement A, p.468 - 470, 2001/05
Times Cited Count:11 Percentile:56.39(Physics, Multidisciplinary)no abstracts in English
Katagiri, Masaki; Sakasai, Kaoru; Nakamura, Tatsuya; To, Kentaro; Takahashi, Hiroyuki*; Nakazawa, Masaharu*
Nuclear Instruments and Methods in Physics Research A, 461(1-3), p.207 - 209, 2001/04
Times Cited Count:3 Percentile:28.22(Instruments & Instrumentation)no abstracts in English
Sakasai, Kaoru; Katagiri, Masaki; To, Kentaro; Nakamura, Tatsuya; Takahashi, Hiroyuki*; Nakazawa, Masaharu*
JAERI-Conf 2001-002, p.639 - 644, 2001/03
no abstracts in English
To, Kentaro; Katagiri, Masaki; Sakasai, Kaoru; Nakamura, Tatsuya; Matsubayashi, Masahito; Takahashi, Hiroyuki*; Nakazawa, Masaharu*
JAERI-Conf 2001-002, p.627 - 638, 2001/03
no abstracts in English
Kishimoto, Maki; Nakamura, Tatsuya; To, Kentaro; Sakasai, Kaoru; Katagiri, Masaki; Takahashi, Hiroyuki*; Nakazawa, Masaharu*
Nihon Genshiryoku Gakkai-Shi, 43(2), p.168 - 181, 2001/02
Times Cited Count:1 Percentile:11.99(Nuclear Science & Technology)no abstracts in English
Sakasai, Kaoru; Katagiri, Masaki; Kishimoto, Maki; Nakamura, Tatsuya; To, Kentaro; Takahashi, Hiroyuki*; Nakazawa, Masaharu*
IEEE Transactions on Nuclear Science, 47(3), p.944 - 947, 2000/06
Times Cited Count:3 Percentile:29.70(Engineering, Electrical & Electronic)no abstracts in English