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Toyoda, Satoshi*; Yoshimura, Masashi*; Sumida, Hirosuke*; Mineoi, Susumu*; Machida, Masatake*; Yoshigoe, Akitaka; Yoshikawa, Akira*; Suzuki, Satoru*; Yokoyama, Kazushi*
Hoshako, 35(3), p.200 - 206, 2022/05
The present status of spatiotemporal depth profiling analysis of the multilayer stacked film interface based on Ambient Pressure X-ray Photoelectron Spectroscopy (APXPS) is presented. To begin with, depth profiles of the multilayer stacked film interfaces have been achieved by time-division Near Ambient Pressure Hard X-ray Angle-Resolved PhotoEmission Spectroscopy data. We then have promoted our methods to quickly perform peak fittings and depth profiling from time-division angle resolved AP-XPS data including spatial resolution, which enables us to realize spatiotemporal depth profiles of the interfaces under reaction conditions such as oxidation and reduction. In addition, it is found that the traditional maximum entropy method (MEM) combined with Jackknife averaging of sparse modeling is effective to perform dynamic measurement of depth profiles with high precision.
-ray spectrometer and its performance under intense 
Cs and 
Co radiation fieldsKaburagi, Masaaki; Shimazoe, Kenji*; Kato, Masahiro*; Kurosawa, Tadahiro*; Kamada, Kei*; Kim, K. J.*; Yoshino, Masao*; Shoji, Yasuhiro*; Yoshikawa, Akira*; Takahashi, Hiroyuki*
Nuclear Instruments and Methods in Physics Research A, 1010, p.165544_1 - 165544_9, 2021/09
Times Cited Count：0 Percentile：0.00(Instruments & Instrumentation)The number of nuclear facilities being decommissioned has been increasing worldwide, in particular following the accident of the Tokyo Electric Power Company Holdings' Fukushima Daiichi Nuclear Power Station in 2011. In these nuclear facilities, proper management of radioactive materials is required. Then, A -ray spectrometer with four segmentations using small volume CeBr
scintillators with a dimension of 
was developed. The four scintillators were coupled to a multi-anode photomultiplier tube specific to intense radiation fields. We performed the -ray exposure study under Cs and Co radiation fields. Under the Cs radiation field, the relative energy resolution at 1375 mSv/h was the relative energy resolution at 1375 mSv/h was 9.2
0.05%, 8.00.08%, 8.0
0.03%, and 9.00.04% for the four channels, respectively.
scintillator under intense -ray fields for nuclear decommissioningKaburagi, Masaaki; Shimazoe, Kenji*; Kato, Masahiro*; Kurosawa, Tadahiro*; Kamada, Kei*; Kim, K. J.*; Yoshino, Masao*; Shoji, Yasuhiro*; Yoshikawa, Akira*; Takahashi, Hiroyuki*; et al.
Nuclear Instruments and Methods in Physics Research A, 988, p.164900_1 - 164900_8, 2021/02
Times Cited Count：14 Percentile：79.54(Instruments & Instrumentation)An increasing number of nuclear facilities have been decommissioned worldwide following the 2011 accident of the TEPCO' Fukushima Daiichi Nuclear Power Station. During the decommissioning, radioactive materials have to be retrieved under proper management. In this study, a small cubic CeBr spectrometer with dimensions of 5 mm 
5 mm 5 mm was manufactured to perform -ray spectroscopy under intense -ray fields. Furthermore, thanks to a fast digital process unit and a customized photomultiplier, the device could perform -ray spectroscopy at dose rates of over 1 Sv/h. The energy resolution (FWHM) at 662 keV ranged from 4.4% at 22 mSv/h to 5.2% at 1407 mSv/h for a Cs radiation field. Correspondingly, at 1333 keV, it ranged from 3.1% at 26 mSv/h to 4.2% at 2221 mSv/h for a Co radiation field, which suggested to realize -ray assessment of 
Cs, Cs, Co, and 
Eu at dose rates of over 1 Sv/h.
measurement and analysis techniques in X-ray photoelectron spectroscopy; From NAP-HARPES to 4D-XPSToyoda, Satoshi*; Yamamoto, Tomoki*; Yoshimura, Masashi*; Sumida, Hirosuke*; Mineoi, Susumu*; Machida, Masatake*; Yoshigoe, Akitaka; Suzuki, Satoru*; Yokoyama, Kazushi*; Ohashi, Yuji*; et al.
Vacuum and Surface Science, 64(2), p.86 - 91, 2021/02
We have developed measurement and analysis techniques in X-ray photoelectron spectroscopy. To begin with, time-division depth profiles of gate stacked film interfaces have been achieved by NAP-HARPES (Near Ambient Pressure Hard X-ray Angle-Resolved Photo Emission Spectroscopy) data. We then have promoted our methods to quickly perform peak fittings and depth profiling from time-division ARPES data, which enables us to realize 4D-XPS analysis. It is found that the traditional maximum entropy method (MEM) combined with Jackknife averaging of sparse modeling in NAP-HARPES data is effective to perform dynamic measurement of depth profiles with high precision.
gamma-ray spectrometer suitable for the decommissioning of the Fukushima Daiichi Nuclear Power StationKaburagi, Masaaki; Shimazoe, Kenji*; Otaka, Yutaka*; Uenomachi, Mizuki*; Kamada, Kei*; Kim, K. J.*; Yoshino, Masao*; Shoji, Yasuhiro*; Yoshikawa, Akira*; Takahashi, Hiroyuki*; et al.
Nuclear Instruments and Methods in Physics Research A, 971, p.164118_1 - 164118_8, 2020/08
Times Cited Count：8 Percentile：56.07(Instruments & Instrumentation)(Al,Ga)
O
scintillator Compton camera mounted on an unmanned helicopterShikaze, Yoshiaki; Nishizawa, Yukiyasu; Sanada, Yukihisa; Torii, Tatsuo; Jiang, J.*; Shimazoe, Kenji*; Takahashi, Hiroyuki*; Yoshino, Masao*; Ito, Shigeki*; Endo, Takanori*; et al.
Journal of Nuclear Science and Technology, 53(12), p.1907 - 1918, 2016/12
Times Cited Count：43 Percentile：95.91(Nuclear Science & Technology)The Compton camera was improved for use with the unmanned helicopter. Increase of the scintillator array from 44 to 88 and expanse of the distance between the two layers contributed to the improvements of detection efficiency and angular resolution, respectively. Measurements were performed over the riverbed of the Ukedo river of Namie town in Fukushima Prefecture. By programming of flight path and speed, the areas of 65 m 60 m and 65 m 180 m were measured during about 20 and 30 minutes, respectively. By the analysis the air dose rate maps at 1 m height were obtained precisely with the angular resolution corresponding to the position resolution of about 10 m from 10 m height. Hovering flights were executed over the hot spot areas for 10-20 minutes at 5-20 m height. By using the reconstruction software the -ray images including the hot spots were obtained with the angular resolution same as that evaluated in the laboratory (about 10
).
-doped YAlO in the temperature range from 4.2 to 175 KYasumune, Takashi; Kurihara, Masakazu*; Maehata, Keisuke*; Ishibashi, Kenji*; Yoshikawa, Akira*
Nuclear Instruments and Methods in Physics Research A, 726, p.37 - 40, 2013/08
Times Cited Count：1 Percentile：10.68(Instruments & Instrumentation)Yb-doped yttrium-aluminum perovskites (YAP:Yb) are expected to be scintillator materials with high light yield and short scintillation decay time because of their charge transfer (CT) luminescence. Since the CT luminescence of Yb is strongly affected by thermal quenching, to use YAP:Yb as a scintillator material, it is necessary to measure the scintillation properties of YAP:Yb at low temperatures. Since it is difficult to detect scintillation light at low temperatures, scintillation properties of YAP:Yb characterized by irradiating with -rays or other radiation below 100 K have not been reported. We conducted measurements of the temperature dependence of emission wavelength spectrum of YAP:Yb by irradiating with 
-rays from a 
Sr/Y source in the temperature range from 4.2 K to 175 K. The emission peak at around 340-350 nm and 500-520 nm were observed in the emission wavelength spectra. The light yield of YAP:Yb was characterized by using an avalanche photodiode in detection of 662 keV -rays from a Cs source in the temperature range from 50 K to 175 K. The light yield increased with decreasing temperature and reached 11,000 photons/MeV at a temperature of 4.2 K.
Nagao, Keisuke*; Okazaki, Ryuji*; Nakamura, Tomoki*; Miura, Yayoi*; Osawa, Takahito; Bajo, Kenichi*; Matsuda, Shintaro*; Ebihara, Mitsuru*; Ireland, T.*; Kitajima, Fumio*; et al.
Science, 333(6046), p.1128 - 1131, 2011/08
Times Cited Count：148 Percentile：94.99(Multidisciplinary Sciences)A steroid surface materials record regolith processes and a history of cosmic-ray irradiation. Noble gas isotopes in three rocky grains from Itokawa have been determined. High concentrations of solar He, Ne, and Ar, as high as those in lunar soils, are released at variable temperatures from each sample. The isotopic compositions are essentially identical to those of solar wind but distinguishable in He relative abundance. These noble gas characteristics can be explained by repeated implantation and preferential loss of solar He by removal of weathered He-rich rim on the grain surface through friction among regolith grains on Itokawa. Residence time of regolith materials on Itokawa is alculated to be shorter than 10 Myr, suggesting that regolith materials of small asteroids would escape easily to space.
Sato, Susumu; Miura, Akihiko; Igarashi, Zenei*; Ikegami, Masanori*; Ueno, Akira; Sako, Hiroyuki; Morishita, Takatoshi; Yoshikawa, Hiroshi; Hasegawa, Kazuo; Kobayashi, Tetsuya
Proceedings of 6th Annual Meeting of Particle Accelerator Society of Japan (CD-ROM), p.298 - 300, 2010/03
no abstracts in English
Sato, Susumu; Miura, Akihiko; Tomisawa, Tetsuo; Sako, Hiroyuki; Morishita, Takatoshi; Ueno, Akira; Hasegawa, Kazuo; Yoshikawa, Hiroshi; Igarashi, Zenei*; Ikegami, Masanori*
Proceedings of 2009 Particle Accelerator Conference (PAC '09) (DVD-ROM), p.3591 - 3593, 2009/05
Ikegami, Masanori*; Lee, S.*; Akikawa, Hisashi*; Igarashi, Zenei*; Kondo, Yasuhiro; Okawa, Tomohiro; Ueno, Akira; Sako, Hiroyuki; Ao, Hiroyuki; Sato, Susumu; et al.
KEK Proceedings 2006-15 (CD-ROM), p.347 - 349, 2007/03
We plan to start the beam commissioning of J-PARC linac with reduced energy of 181 MeV in the end of this year. Detailed commissioning strategies for the linac and the succeeding beam transport line, to which we refer as L3BT or Linac-to-3-GeV-synchrotron Beam Transport, will be presented in this talk. The emphasis will be put on the commissioning procedures for two debuncher cavities and a transverse collimator system located in L3BT, because they are key elements in determining the final beam quality at the injection point to the succeeding 3-GeV synchrotron. The unique design and features of the collimator system are also presented.
Sato, Susumu; Tomisawa, Tetsuo; Hiroki, Fumio; Lee, S.*; Igarashi, Zenei*; Ikegami, Masanori*; Ueno, Akira; Kondo, Yasuhiro; Hasegawa, Kazuo; Toyama, Takeshi*; et al.
Proceedings of 1st Annual Meeting of Particle Accelerator Society of Japan and 29th Linear Accelerator Meeting in Japan, p.467 - 469, 2004/08
As a joint project of KEK and JAERI, a MW class of high intensity proton accelerator (J-PARC), consisting of Linac, 3 GeV-RCS, 50 GeV-MR, is under construction. For this accelerator, it is required to minimize the beam loss (typically, lower than0.1
1 W/m at the linac). To achieve the requirement, beam trajectory needs to be controlled with accuracy of some 100 
m. The first stage of the acceleration (up to 181 MeV during the first stage of construction) is done by linac. The beam position monitor (BPM) in the linac utilizes 4 stripline pickups (50 ohm) on the beam transportation chamber. In this paper, systematic calibration of the BPM is described.
Sato, Susumu; Igarashi, Zenei*; Lee, S.*; Tomisawa, Tetsuo; Hiroki, Fumio; Kishiro, Junichi; Ikegami, Masanori*; Kondo, Yasuhiro; Hasegawa, Kazuo; Ueno, Akira; et al.
Proceedings of 22nd International Linear Accelerator Conference (LINAC 2004), p.429 - 431, 2004/00
As a joint project of KEK and JAERI, a MW class of high intensity proton accelerator (J-PARC), consisting of Linac, 3 GeV-RCS, 50 GeV-MR, is under construction at Tokai, Japan. For this accelerator, it is required to minimize the beam loss (typically, lower than 0.11 W/m at the linac). To achieve the requirement, beam trajectory needs to be controlled with accuracy of some 100 micro-meter. The first stage of the acceleration (up to 181 MeV during the first stage of construction) is done by linac. The beam position monitor (BPM) in the linac utilizes 4 strip-line pickups (50 ohm) on the beam transportation chamber. In this paper, systematic calibration of the BPM is described.
; Yoshikawa, Shinji*; ; Ohshima, Hiroyuki
PNC TN9410 87-143, 357 Pages, 1987/10
SSC-L is a best estimate computer code for the whole plant system thermohydraulic analysis. It is applied to all the categories of accidents, i.e, protected accidents (PLOHS, PLOF, and LOPI) and unprotected accidents (ULOF, UTOP, ULOHS and ULOPI). The purpose of this study is to improve the capability of SSC-L so that it can be used for the safety evaluation of FBR system extensively with sufficient accuracy. Phenomenological models and system/component models are newly developed and added to SSC-L. A number of modules originally used in SSC-L are modified or replaced. As a result, the modifications are related to the most part of the computational modules in SSC-L. The following models, for example, are developed regarding the in-vessel and heat transport system termohydraulics such as: (a)modification of two-region upper plenum model, (b)multi-pressure point lower plenum model, (c)reactivity feedback effect for unprotected accident analysis, (d)whole core inter-subassembly heat transfer model, (e)modeling of heat losses through the piping wall, (f)decay heat removal systems, i.e., IRACS and DRACS, model, (g)more stable and accurate IHX heat transfer model, (h)modification of the pipe break model, etc. In addition, a graphic package for SSC is developed to display the computational results in the form of two dimensional time history. The improved SSC-L is applied to the analysis of various type of accidents and the effectiveness of the improvement is demonstrated. It is concluded that the first stage of the SSC-L development has been completed. This code is to be used as an effective computational tool for the safety analysis of Monju and larger scale FBR from the viewpoint of the whole plant behavior.
; ; Yoshikawa, Shinji*
PNC TN9410 87-113, 75 Pages, 1987/07
Loop-Version of Super System Code (SSC-L) has been applied to the analysis of natural circulation (NC) test from full power (100 MWt) in JOYO Mk-II core (irradiation core). The simulation using SSC-L covers 10,000 seconds of real time. The purposes of this study are to validate the computer program and to point out future works for improving the analytical accuracy. It has been found from this study that the computational results agree well with the experimental ones throughout the whole plant system. The difference between calculated and measured coolant temperatures is 15 degrees at fuel sub-assembly exits, and 20 degrees in the primary and secondary heat transport systems (HTSs) at most. Therefore, SSC-L can simulate thermohydraulic performance across the whole core region as well as in the primary and secondary HTSs with sufficient accuracy. These results indicate that computational models in SSC-L modified or developed so far are valid, and the code is applicable to larger scale FBRs. The difference between the computational and measured results has been examined, and sensitive parameters are identified based on the uncertainty analysis. The following future works have been pointed out for improving the accuracy of the analysis further; (1)two-dimensional representation of upper and/or lower plena, (2)refinement in the correlation of friction pressure losses at the fuel SAs in NC condition, (3)evaluation of the flow resistance of main coolant pump in NC condition.
Yoshikawa, Shinji*; Maekawa, I.*; ; Ninokata, Hisashi
PNC TN941 85-58, 60 Pages, 1985/03
An interactive use has been made of the plant-wide system dynamics code SSC-L and the multi-dimensional analysis code COMMIX-1A to simulate the natural circulation test of the experimental fast reactor JOYO. Investigative sensitivity studies are presented which depict the effect and relative importance of various parameters on the whole core natural circulation performances including the inter-subassembly heat transfer, pressure distribution at the core exit plane, cross flow through the gap between the core exit plane and the flow straightener and the multi-dimensional upper- and lower-plenum thermohydraulics. The results from the current modeling of SSC-L, neglecting most of the above effects, have confirmed its potential to predict with sufficient accuracy the system response under the natural circulation condition by providing the inter-subassembly heat transfer model.
; Yoshikawa, Shinji*; Ninokata, Hisashi;
PNC TN941 84-134, 42 Pages, 1984/10
Natural circulation test conducted in the experimental reactor JOYO with its breeding core has been analyzed using the plant dynamics analysis code SSC-L. In order to perform this analysis, DHX model has been developed and added to the code. The whole plant of JOYO has been simulated and the following results has been obtained: (1)Good agreement has been obtained with respect to the primary flow rate and the peak of subassembly outlet temperature. (2)The coolant temperature at the top of subassembly is very sensitive to the modelings of primary pump frictional torque and the gap conductance before the temperature reaches the peak value. (3)Under the quasi-steady state condition after the temperature has passed its peak value, the secondary loop flow rate controls the heat removal rate through IHX and gives significant effects on the primary coolant flow rate, thus, the coolant behavior in the core. (4)The ratio of the decay power to fission power dominates the in-core coolant behavior both in short term and long term transients. As stated above, the coolant behavior is found to be very sensitive to the parameters which possess relatively large uncertainties. Therefore, it is concluded that the further sensitivity study is needed to give the quantitative upper and lower bounds of the estimates.
; ; ; ; ;
JAERI-M 84-044, 51 Pages, 1984/03
no abstracts in English
Okubo, Minoru; ; ; ; ; ; ; ;
Nihon Genshiryoku Gakkai-Shi, 20(3), p.195 - 206, 1978/03
Times Cited Count：3no abstracts in English
