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CNguyen, B. V. C.*; Murakami, Kenta*; Chena, L.*; Phongsakorn, P. T.*; Chen, X.*; Hashimoto, Takashi; Hwang, T.*; Furusawa, Akinori; Suzuki, Tatsuya*
Nuclear Materials and Energy (Internet), 39, p.101639_1 - 101639_9, 2024/06
Ariyoshi, Gen; Obayashi, Hironari; Sasa, Toshinobu
Journal of Nuclear Science and Technology, 59(9), p.1071 - 1088, 2022/09
Times Cited Count：1 Percentile：29.26(Nuclear Science & Technology)Electromagnetic induction method is one of the effective techniques for local velocity measurement in heavy liquid metals. Ricou and Vives' probe and Von Weissenfluh's probe are famous instrumentations using a permanent magnet. However, sensitivity and measurement volume of the probes show unexpected variation since demagnetization of the magnet is occurred by temperature increase up to the Curie temperature. In this study, electromagnetic probe incorporating a miniature electromagnet was newly developed to overcome such unexpected variation. The diameter and the length of the sensor was 6 mm and 155 mm, respectively. The sensitivity and the measurement volume of the probe were assessed by measurement of local velocity of flowing mercury in a square channel. To clarify the validity for the measured velocity profiles, numerical velocity profiles were calculated and compared with experiment. And the validity for the measured velocity profiles were confirmed by calculated result.
6 rod bundleHan, X.*; Shen, X.*; Yamamoto, Toshihiro*; Nakajima, Ken*; Sun, Haomin; Hibiki, Takashi*
International Journal of Heat and Mass Transfer, 144, p.118696_1 - 118696_19, 2019/12
Times Cited Count：15 Percentile：64.13(Thermodynamics)Xiao, Y.*; Shen, X.*; Miwa, Shuichiro*; Sun, Haomin; Hibiki, Takashi*
Konsoryu Shimpojiumu 2018 Koen Rombunshu (Internet), 2 Pages, 2018/08
In order to develop constitutive equations of two-fluid model in rod bundle flow channels, experiments of adiabatic air-water upward two-phase flow in 66 rod bundle flow channel were performed. Local flow parameters such as void fraction, interfacial area concentration (IAC) and so on were measured by a double-sensor optical probe. The area-averaged void fraction and IAC data were compared with the predictions from a drift-flux model and an IAC correlation.
Oka, Hiroshi; Tanno, Takashi; Otsuka, Satoshi; Yano, Yasuhide; Kaito, Takeji
Nuclear Materials and Energy (Internet), 16, p.230 - 237, 2018/08
Times Cited Count：4 Percentile：38.11(Nuclear Science & Technology)Shen, X.*; Schlegel, J. P.*; Hibiki, Takashi*; Nakamura, Hideo
Nuclear Engineering and Design, 333, p.87 - 98, 2018/07
Times Cited Count：11 Percentile：34.62(Nuclear Science & Technology)Shen, X.*; Sun, Haomin; Deng, B.*; Hibiki, Takashi*; Nakamura, Hideo
International Journal of Heat and Fluid Flow, 67(Part A), p.168 - 184, 2017/10
Times Cited Count：17 Percentile：62.14(Thermodynamics)An experimental study on upward bubbly air-water flows in a vertical large-diameter square duct have been performed by mainly using four-sensor probes. Local measurements of interfacial area concentration (IAC), void fraction, 3D bubble velocity vector and bubble diameter at 3 axial positions were conducted. Although the interfacial area transport equation (IATE) and its bubble coalescence and breakup models have already played an important role in predicting the IAC in general two-phase flow fields, they are mainly developed based on the two-phase flow experimental data taken in round pipes or small diameter channels. To confirm their usability in large-diameter square duct, this study has evaluated the 1D one-group IATE with its 6 sets of bubble coalescence and breakup models with the presently-obtained database. It was found the relative error between the best prediction and the database was 25%.
Shen, X.*; Sun, Haomin; Deng, B.*; Hibiki, Takashi*; Nakamura, Hideo
Proceedings of 17th International Topical Meeting on Nuclear Reactor Thermal Hydraulics (NURETH-17) (USB Flash Drive), 14 Pages, 2017/09
An experimental study on the upward bubbly air-water flows in a vertical large-diameter square duct have been performed by using four-sensor probes. The four-sensor probe were applied in the local measurements at 3 axial positions along the flow direction to obtain interfacial area concentration, 3-D bubble velocity vector and bubble diameter. The obtained void fraction, interfacial area concentration, 3-D bubble velocity vector and bubble diameter provided valuable insight into the flow structure and will serve as a valuable database to develop the mechanistic models for interfacial area transport equation sources and sinks.
Shen, X.*; Schlegel, J. P.*; Hibiki, Takashi*; Nakamura, Hideo
Proceedings of 2017 Japan-US Seminar on Two-Phase Flow Dynamics (JUS 2017), 6 Pages, 2017/06
Oka, Hiroshi; Tanno, Takashi; Otsuka, Satoshi; Yano, Yasuhide; Uwaba, Tomoyuki; Kaito, Takeji; Onuma, Masato*
Nuclear Materials and Energy (Internet), 9, p.346 - 352, 2016/12
Times Cited Count：21 Percentile：88.55(Nuclear Science & Technology)Shen, X.*; Sun, Haomin; Deng, B.*; Hibiki, Takashi*; Nakamura, Hideo
Progress in Nuclear Energy, 89, p.140 - 158, 2016/05
Times Cited Count：23 Percentile：89.61(Nuclear Science & Technology)An experimental study was performed on the local structure of upward air-water two-phase flow in a vertical large diameter square duct by using a four-sensor probe. The four-sensor probe method classifying spherical and non-spherical bubbles was applied as a key measurement way to obtain local parameters such as 3-D bubble velocity vector, bubble diameter and interfacial area concentration. Both the local void fraction and interfacial area concentration indicated radial core-peak and wall-peak distributions at low and high liquid flow rates respectively. The 2 components of the bubble velocity vector in the cross-section revealed that there exists a rotating secondary flow in the octant symmetric triangular area and the magnitude of the rotating secondary flow increases with the liquid flow rate. Some of constitutive correlations of drift-flux model and interfacial area concentration are reviewed to study their predictabilities against the present data.
Hata, Koji*; Niunoya, Sumio*; Aoyagi, Kazuhei; Fujita, Tomoo
Dai-44-Kai Gamban Rikigaku Ni Kansuru Shimpojiumu Koenshu (CD-ROM), p.319 - 324, 2016/01
Long-term monitoring and EDZ (Excavated Damage Zone) evaluation is carried out by this multi-optical measurement probe in the depth of 350m vertical shaft of Horonobe Underground Research Center project of the Japan Atomic Energy Agency. We have developed a multi-optical measurement probe incorporating an optical AE sensor, an optical water pressure sensor and an optical temperature sensor. Result of the measurement of AE, water pressure and temperature, it was made clear the influence of the shaft excavation. And from the source location analysis, it was found EDZ was less than 1.5m from shaft wall.
Amemiya, Hiroshi*; Uehara, Kazuya
Japanese Journal of Applied Physics, Part 1, 45(1A), p.247 - 249, 2006/01
Times Cited Count：4 Percentile：17.05(Physics, Applied)A method for detecting the separatrix surface in the edge plasma in Tokamak is presented. Two sets of double probes whose front surfaces are shifted by a small distance are mounted and the difference of the currents is measured using a differential amplifier. When the separatrix surface reaches the probes, a current increment appears in the differential amplifier, giving a signal of the arrival of the separatrix. Procedures of obtaining plasma parameters including the ion temperature are described.
Shibamoto, Yasuteru
JAERI-Research 2005-016, 127 Pages, 2005/08
JAERI-Research-2005-016.pdf:4.54MB
no abstracts in English
Amemiya, Hiroshi*; Wada, Motoi*; Toyoda, Hirotaka*; Nakamura, Keiji*; Ando, Akira*; Uehara, Kazuya; Oyama, Koichiro*; Sakai, Osamu*; Tachibana, Kunihide*
Purazuma, Kaku Yugo Gakkai-Shi, 81(7), p.482 - 525, 2005/07
This article is asked to write by the Japan Society of Plasma Science and Nuclear Fusion Research. The probe diagnostics in fusion plasma is explaind for many readers of the Journal of Plasma and Fusion Research, who have much concerned on various aspects.In section one, the method to estimate the electron temperature and the density as well as the electron energy distribution function with the single probe is given. In section two, the method to estimate the ion temperature and the flow velocity with the double probe is given. The practical measurements are explained introducing the data obtained at JFT-2, JFT-2a and JFT-2M in JAERI tokamak.
Asakura, Nobuyuki; Takechi, Manabu; Oyama, Naoyuki; Nakano, Tomohide
Journal of Nuclear Materials, 337-339, p.712 - 716, 2005/03
Times Cited Count：14 Percentile：67.75(Materials Science, Multidisciplinary)Fast sampling diagnostics such as Langmuir probes and magnetic pick-up coils were developed in JT-60U. ELM radial expansion was important to understand the heat and particle load on the first wall. Enhancement and radial expansion of the SOL plasma just after ELM were investigated at Low-Field-Side and High-Field-Side. Ion saturation current (
) profile was described by two-exponential fit (i.e. 1st and 2nd lgi). Enhancement of the particle flux was different in poloidal location: particle flux profile became very flat, in particular, at HFS. Radial expansion speed at LFS was evaluated in the range of 1-3 km/s. ELM plasma flux in LFS and HFS divertors was investigated. Fast changes of js and floating potential (Vf) were measured. Large negative Vf was observed and durations of the negative js and Vf were 
100 ms, which was shorter than heat deposition (250 ms). The large negative js and Vf near both strike-points suggested fast electron deposition rather than thermal electric current. Influence of the divertor sheath on the heat deposition time is discussed.
Kawashima, Hisato; Uehara, Kazuya; Nishino, Nobuhiro*; Kamiya, Kensaku; Tsuzuki, Kazuhiro; Bakhtiari, M.; Nagashima, Yoshihiko*; Ogawa, Hiroaki; Hoshino, Katsumichi; Suzuki, Sadaaki; et al.
Purazuma, Kaku Yugo Gakkai-Shi, 80(11), p.907 - 908, 2004/11
A comparison of divertor heat load between ELMy and "High Recycling Steady" (HRS) H-mode was carried out by fast measurements of the two dimensional 
emission, and the divertor electron temperature and ion saturation current on JFT-2M. They brought an attractive feature of HRS H-mode that the heat load was reduced to the level on time average that for ELMy H-mode, being able to avoid the severe heat load during pulsed ELM event. It was also indicated that the HRS H-mode was dominated by an enhancement of particle transport, whereas both heat and particle transport increased abruptly at ELM event.
Kamiya, Kensaku; Miura, Yukitoshi; Ido, Takeshi*; Hamada, Yasuji*
Review of Scientific Instruments, 74(9), p.4206 - 4208, 2003/09
Times Cited Count：0 Percentile：0.01(Instruments & Instrumentation)no abstracts in English
Meigo, Shinichiro; Noda, Fumiaki*; Fujimori, Hiroshi*; Ikeda, Yujiro
Proceedings of ICANS-XVI, Volume 3, p.967 - 976, 2003/07
In J-PARC project, spallation target is irradiated by 3 GeV proton beam of 1 MW. Due to hands on maintenance for the proton beam lines, loss of proton beam is limited less than 1 W/m. Since it is difficult to predict the phase space distribution of the proton beam, we decided that the beam line have to be larger acceptance for 324 
mrad, which is determined by the collimator located in the synchrotron. Distortion of proton beam is caused by the by the instability of angle at the extraction of 3-GeV synchrotron, miss alignment of the magnet, and un-uniformity of the magnet field. In this study, the distortion is calculated. In order to fit the conditions, the stability of extraction angles should be kept smaller than 0.2 mrad. As for the magnetic field, it is found that the uniformity should be kept better 5x10
and 2x10
for bending and quadruple magnets, respectively. It is also found the error of alignments should be limited smaller than 1.0 mm and 1.0 mrad.
Shibamoto, Yasuteru; Sagawa, Jun*; Kukita, Yutaka*; Nakamura, Hideo
Konsoryu, 17(2), p.171 - 179, 2003/06
A bifunctional probe was developed for simultaneous, high-speed measurement of local temperature and phase of fluid at the same place. It was designed for application to water/melt multi-phase experiments involving transient boiling of water on the surface of molten metal. An unsheathed thermocouple (TC) of a small wire diameter was used for phase detection, that is distinction of melt/water/vapor phase, as well as for temperature measurement of each phase. The phase was detected by measuring the electric impedance between the TC and the ground. A 100-kHz AC signal was imposed on the TC wire for this purpose. The AC signal was filtered out from the temperature signal before it was amplified. With the first design of low-pass filter (LPF), however, a large noise was induced in the temperature signal every time the TC was grounded electrically by contact with molten metal. This problem was overcome by redesigning the LPF. The final design succeeded in measuring the quick movements of interface and the temperature changes in the individual phases in a water-melt-vapor multiphase flow.
