The Experts below are selected from a list of 21945 Experts worldwide ranked by ideXlab platform

Hiroo Kondo - One of the best experts on this subject based on the ideXlab platform.

  • verification of accuracy of contact probe distance meter for Lithium target of fusion neutron source
    Fusion Engineering and Design, 2020
    Co-Authors: Takafumi Okita, Hiroo Kondo, Eiji Hoashi, Shota Entani, Kotaro Watanabe, Masahiro Higashi, Changho Park, Makoto M Nakamura, Kentaro Ochiai, Atsushi Kasugai
    Abstract:

    Abstract An accelerator based intense neutron sources such as the IFMIF, A-FNS and DONES produce neutron flux by a stripping reaction between Lithium (Li) and deuteron for testing various materials for fusion reactor. In these fusion neutron sources, a Liquid Li free-surface jet is appLied as the Liquid Li target. For the development of the Li target system, the variation in the thickness of the Li jet was measured using the Li loop of Osaka University. At the Osaka Univ., a lot of knowledge about the surface fluctuation of the Li jet had been obtained by using the electro-contact type distance meter (referred to as the probe apparatus herein). Besides, for the stable and safety operation of the faciLity, the probe apparatus is planned to be used as a safety interlock system for beam irradiation in actual intense neutron source because of its simple structure. Therefore, it is desirable to verify its accuracy. Especially, it is expected that false detection and undetected waves, which is particular to the contact-type apparatus, could cause errors. Then in this study, the measurement using non-contact type distance meter using optical comb (referred to as the laser probe herein) was conducted, and then the error of the results of the probe apparatus is evaluated by comparing results.

  • cavitation inception upstream of Liquid Lithium target for intense fusion neutron source
    Fusion Engineering and Design, 2017
    Co-Authors: Hiroo Kondo, Tomohiro Furukawa, Yasushi Hirakawa, Takuji Kanemura, E Wakai
    Abstract:

    Abstract A Liquid Li free-surface stream flowing at 15 m/s under a high vacuum of 10 −3  Pa is to serve as a beam target (Li target) for an intense neutron source such as the planned International Fusion Materials Irradiation FaciLity (IFMIF). This study examines cavitation-Like acoustic noise occurring upstream of the Li target. This noise is detected using an acoustic emission sensor that is installed at a Li target assembly in which the Li target was produced. A time-frequency analysis by continuous wavelet transform (CWT) was performed to characterize the acoustic noise, which determined the cause of the acoustic signal was cavitation. And the occurrence of cavitation was discussed by using BernoulLi’s equation and compared with the experimental observations. As a consequence, we revealed a criterion of inception of cavitation and a proper startup pressure of the Li target, which will be a design basis for the future IFMIF Li target faciLity.

  • measurement of transient flow characteristics of target flow in water experiment for ifmif
    Fusion Engineering and Design, 2017
    Co-Authors: Shotaro Matsuda, Hiroo Kondo, Takuji Kanemura, Sachiko Yoshihashi, Eiji Hoashi, Takafumi Okita, Sayaka Kaji, H Horiike
    Abstract:

    Abstract International Fusion Material Irradiation FaciLity (IFMIF) is the faciLity generating the high flux and high energy neutrons to develop fusion reactor materials. In IFMIF, high-speed Liquid Lithium (Li) jet is used as the target irradiated by deuteron beams. Since the Li jet must flow with high velocity for heat removal, it is important to research on the Li flow characteristics. These researches have been aimed toward the steady-state Li flow characteristics. On the other hand, in the actual IFMIF, it is also necessary to clarify transient flow characteristics at start and stop of the system for the operation. In this study, water experiment to obtain them at start and stop is thus conducted. Water can be substituted for Liquid Li as the target, because the kinematic viscosity of the Li at operation temperature in IFMIF is nearly equal to that of water at normal temperature and pressure. Flow patterns of the water jet at test section which consists of a two-staged contraction nozzle, a vertical concave flow channel are observed by laser probe method and high-speed video camera. As a result, the flow pattern at start and stop was successfully observed. The flow at stop became stable by venting gas.

  • ifmif eveda Lithium test loop design and fabrication technology of target assembly as a key component
    Nuclear Fusion, 2011
    Co-Authors: Hiroo Kondo, Tomohiro Furukawa, Yasushi Hirakawa, Kazuyuki Nakamura, K Watanabe, Takuji Kanemura, E Wakai, H Horiike, Nobuo Yamaoka, Hirokazu Sugiura
    Abstract:

    The engineering vaLidation and engineering design activity (EVEDA) for the International Fusion Materials Irradiation FaciLity (IFMIF) is proceeding as one of the ITER broader approach activities. In the concept of the IFMIF, two 40 MeV deuteron beams are injected into a Liquid Li stream (Li target) flowing at a velocity of 15 m s−1. The EVEDA Li test loop (ELTL) is aimed at vaLidating the hydrauLic stabiLity of the Li target at a velocity up to 20 m s−1 under a vacuum condition of 10−3 Pa as the most important issue. Construction of the ELTL, which is the largest Liquid metal loop possessing 5.0 m3 Li for the fusion research ever, was completed in the O-arai Research & Development Center in the Japan Atomic Energy Agency on 22 November 2010. This paper presents the design and fabrication technology of a target assembly called integrated target assembly, in which the Li target is produced by a contraction nozzle along a concave channel. There are two concepts regarding the target assembly: the integrated target assembly and the bayonet target assembly. Both target assembLies are outLined in this paper, and then the newly proposed design of the integrated target assembly for the ELTL and its fabrication technology are given. The integrated target assembly was processed by a five-axis milLing machine and the processing accuracy was measured by 3D measurement tools. Finally, methods appLied for the vaLidation of the stabiLity of the Li target are introduced in this paper.

  • ifmif eveda Lithium test loop design and fabrication technology of target assembly as a key component
    Nuclear Fusion, 2011
    Co-Authors: Hiroo Kondo, Mizuho Ida, Tomohiro Furukawa, Yasushi Hirakawa, Kazuyuki Nakamura, K Watanabe, Takuji Kanemura, E Wakai, H Horiike, Nobuo Yamaoka
    Abstract:

    The engineering vaLidation and engineering design activity (EVEDA) for the International Fusion Materials Irradiation FaciLity (IFMIF) is proceeding as one of the ITER broader approach activities. In the concept of the IFMIF, two 40 MeV deuteron beams are injected into a Liquid Li stream (Li target) flowing at a velocity of 15 m s−1. The EVEDA Li test loop (ELTL) is aimed at vaLidating the hydrauLic stabiLity of the Li target at a velocity up to 20 m s−1 under a vacuum condition of 10−3 Pa as the most important issue. Construction of the ELTL, which is the largest Liquid metal loop possessing 5.0 m3 Li for the fusion research ever, was completed in the O-arai Research & Development Center in the Japan Atomic Energy Agency on 22 November 2010. This paper presents the design and fabrication technology of a target assembly called integrated target assembly, in which the Li target is produced by a contraction nozzle along a concave channel. There are two concepts regarding the target assembly: the integrated target assembly and the bayonet target assembly. Both target assembLies are outLined in this paper, and then the newly proposed design of the integrated target assembly for the ELTL and its fabrication technology are given. The integrated target assembly was processed by a five-axis milLing machine and the processing accuracy was measured by 3D measurement tools. Finally, methods appLied for the vaLidation of the stabiLity of the Li target are introduced in this paper.

R Maingi - One of the best experts on this subject based on the ideXlab platform.

  • Lithium splashing from flowing Liquid Lithium Limiter and its effect on high confinement plasma performance in east tokamak
    Nuclear materials and energy, 2020
    Co-Authors: G Z Zuo, R Maingi, Z Sun, X C Meng, Z L Tang, Y Z Qian, M Huang
    Abstract:

    Abstract To study the potential appLications of Liquid Lithium (Li) as plasma facing material, the third generation of flowing Liquid Li (FLiLi) Limiter has been designed and successfully tested in EAST tokamak H-mode discharges in the 2018 run campaign. The stabiLity of Liquid Li on FLiLi surface, and Li splashing and its effect on the plasma performance are investigated in detail. Li splashing was observed in L-mode and H-mode discharges due to Rayleigh-Taylor (R-T) instabiLity, resulting from electromagnetic forces J → × B → . Li splashing in low-parameter plasma decreased both core and edge electron temperatures, resulting in the degradation of plasma energy confinement and even H-L back transition, however, it almost did not influence plasma confinement performance in high-parameter plasma. These findings indicate that high-parameter plasma has higher tolerance to Li impurities than low-parameter plasma. By contrast, tungsten splashing from the melted layer on the upper divertor was also induced by the R-T instabiLity but generally resulted in plasma disruption, which suggests lower tolerance to tungsten impurities in EAST tokamak.

  • Experiments of continuously and stably flowing Lithium Limiter in EAST towards a solution for the power exhaust of future fusion devices
    'Elsevier BV', 2019
    Co-Authors: G Z Zuo, R Maingi, Z Sun, Daniel Andruczyk, M Huang, K. Tritz, Q.x. Yang, X C Meng
    Abstract:

    Liquid Lithium (Li) can partly ameLiorate Lifetime and power-exhaust issues of plasma facing components (PFCs) by enabLing a self-heaLing, self-replenishing surface with a reduced susceptibiLity to neutron damage in future fusion devices. To assess operational stabiLity and heat-exhaust capabiLity under tokamak exposure, two generations of continuously flowing Liquid Li (FLiLi) Limiters on the concept of a thin flowing Li film have been successfully designed and tested in high performance discharges in EAST. The design uses a circulating Li layer with a thickness of

  • upgraded flowing Liquid Lithium Limiter for improving Li coverage uniformity and erosion resistance in east device
    Review of Scientific Instruments, 2017
    Co-Authors: G Z Zuo, R Maingi, Qingxi Yang, Z Sun, Ming Huang, Y J Chen, Xiaolin Yuan, X C Meng, C Gentile, A Carpe
    Abstract:

    We report on design and technology improvements for a flowing Liquid Lithium (FLiLi) Limiter inserted into auxiLiary heated discharges in the experimental advanced superconducting tokamak device. In order to enhance Li coverage uniformity and erosion resistance, a new Liquid Li distributor with homogenous channels was implemented. In addition, two independent electromagnetic pumps and a new horizontal capillary structure contributed to an improvement in the observed Li flow uniformity (from 30% in the previous FLiLi design to >80% in this FLiLi design). To improve Limiter surface erosion resistance, hot isostatic press technology was appLied, which improved the thermal contact between thin stainless steel protective layers covering the Cu heat sink. The thickness of the stainless steel layer was increased from 0.1 mm to 0.5 mm, which also helped macroscopic erosion resiLience. Despite the high auxiLiary heating power up to 4.5 MW, no Li bursts were recorded from FLiLi, underscoring the improved performance of this new design.

  • mitigation of plasma material interactions via passive Li efflux from the surface of a flowing Liquid Lithium Limiter in east
    Nuclear Fusion, 2017
    Co-Authors: G Z Zuo, R Maingi, Qingxi Yang, C Gentile, K. Tritz, Jie Ren, Z J Sun, Z X Chen, L Zakharov, Xiancai Meng
    Abstract:

    A new flowing Liquid Li Limiter (FLiLi) based on the concept of a thin flowing film has been successfully designed and tested in the EAST device in 2014. A bright Li radiative mantle at the plasma edge was observed during discharges using FLiLi, resulting from passive Li injection and transport in the scrape-off layer (SOL) plasma. Li particle efflux from the FLiLi surface into the plasma was estimated at >5 × 1020 atom s−1, due to surface evaporation and sputtering, and accompanied with a few small Li droplets ~1 mm diameter that were ejected from FLiLi. The Li efflux from FLiLi was ionized by the SOL plasma and formed a Li radiation band that originated from the FLiLi surface, and then spread toroidally by SOL plasma flow. The Li radiative mantle appeared to partly isolate the plasma from the wall, reducing impurity release from the wall materials, and possibly leading to a modest improvement in confinement. In addition, strong Li radiation reduced the particle and heat fluxes impacting onto the divertor plate, with certain similarities to heat flux reduction and detachment onset via low-Z impurity injection.

  • Lithium as a plasma facing component to optimize the edge plasma
    IEEE Symposium on Fusion Engineering, 2015
    Co-Authors: R Maingi, R Majeski, M A Jaworski, J E Menard, R Kaita
    Abstract:

    The use of Lithium to coat plasma-facing components (PFCs) or serve directly as Liquid PFCs has resulted in energy confinement improvement in several devices. Coupled with the demonstrated abiLity of Liquid Li to exhaust high power fluxes, the use of Li could resolve the two leading problems of high-Z PFCs. The effect of Li in NSTX, EAST, and DIII-D is compared, and common features are identified. A compact spherical tokamak-based Fusion Nuclear Science FaciLity design could deLiver an attractive neutral wall loading for materials testing, with Li PFCs enabLing access to the required high confinement scenarios.

Takuji Kanemura - One of the best experts on this subject based on the ideXlab platform.

  • cavitation inception upstream of Liquid Lithium target for intense fusion neutron source
    Fusion Engineering and Design, 2017
    Co-Authors: Hiroo Kondo, Tomohiro Furukawa, Yasushi Hirakawa, Takuji Kanemura, E Wakai
    Abstract:

    Abstract A Liquid Li free-surface stream flowing at 15 m/s under a high vacuum of 10 −3  Pa is to serve as a beam target (Li target) for an intense neutron source such as the planned International Fusion Materials Irradiation FaciLity (IFMIF). This study examines cavitation-Like acoustic noise occurring upstream of the Li target. This noise is detected using an acoustic emission sensor that is installed at a Li target assembly in which the Li target was produced. A time-frequency analysis by continuous wavelet transform (CWT) was performed to characterize the acoustic noise, which determined the cause of the acoustic signal was cavitation. And the occurrence of cavitation was discussed by using BernoulLi’s equation and compared with the experimental observations. As a consequence, we revealed a criterion of inception of cavitation and a proper startup pressure of the Li target, which will be a design basis for the future IFMIF Li target faciLity.

  • measurement of transient flow characteristics of target flow in water experiment for ifmif
    Fusion Engineering and Design, 2017
    Co-Authors: Shotaro Matsuda, Hiroo Kondo, Takuji Kanemura, Sachiko Yoshihashi, Eiji Hoashi, Takafumi Okita, Sayaka Kaji, H Horiike
    Abstract:

    Abstract International Fusion Material Irradiation FaciLity (IFMIF) is the faciLity generating the high flux and high energy neutrons to develop fusion reactor materials. In IFMIF, high-speed Liquid Lithium (Li) jet is used as the target irradiated by deuteron beams. Since the Li jet must flow with high velocity for heat removal, it is important to research on the Li flow characteristics. These researches have been aimed toward the steady-state Li flow characteristics. On the other hand, in the actual IFMIF, it is also necessary to clarify transient flow characteristics at start and stop of the system for the operation. In this study, water experiment to obtain them at start and stop is thus conducted. Water can be substituted for Liquid Li as the target, because the kinematic viscosity of the Li at operation temperature in IFMIF is nearly equal to that of water at normal temperature and pressure. Flow patterns of the water jet at test section which consists of a two-staged contraction nozzle, a vertical concave flow channel are observed by laser probe method and high-speed video camera. As a result, the flow pattern at start and stop was successfully observed. The flow at stop became stable by venting gas.

  • ifmif eveda Lithium test loop design and fabrication technology of target assembly as a key component
    Nuclear Fusion, 2011
    Co-Authors: Hiroo Kondo, Tomohiro Furukawa, Yasushi Hirakawa, Kazuyuki Nakamura, K Watanabe, Takuji Kanemura, E Wakai, H Horiike, Nobuo Yamaoka, Hirokazu Sugiura
    Abstract:

    The engineering vaLidation and engineering design activity (EVEDA) for the International Fusion Materials Irradiation FaciLity (IFMIF) is proceeding as one of the ITER broader approach activities. In the concept of the IFMIF, two 40 MeV deuteron beams are injected into a Liquid Li stream (Li target) flowing at a velocity of 15 m s−1. The EVEDA Li test loop (ELTL) is aimed at vaLidating the hydrauLic stabiLity of the Li target at a velocity up to 20 m s−1 under a vacuum condition of 10−3 Pa as the most important issue. Construction of the ELTL, which is the largest Liquid metal loop possessing 5.0 m3 Li for the fusion research ever, was completed in the O-arai Research & Development Center in the Japan Atomic Energy Agency on 22 November 2010. This paper presents the design and fabrication technology of a target assembly called integrated target assembly, in which the Li target is produced by a contraction nozzle along a concave channel. There are two concepts regarding the target assembly: the integrated target assembly and the bayonet target assembly. Both target assembLies are outLined in this paper, and then the newly proposed design of the integrated target assembly for the ELTL and its fabrication technology are given. The integrated target assembly was processed by a five-axis milLing machine and the processing accuracy was measured by 3D measurement tools. Finally, methods appLied for the vaLidation of the stabiLity of the Li target are introduced in this paper.

  • ifmif eveda Lithium test loop design and fabrication technology of target assembly as a key component
    Nuclear Fusion, 2011
    Co-Authors: Hiroo Kondo, Mizuho Ida, Tomohiro Furukawa, Yasushi Hirakawa, Kazuyuki Nakamura, K Watanabe, Takuji Kanemura, E Wakai, H Horiike, Nobuo Yamaoka
    Abstract:

    The engineering vaLidation and engineering design activity (EVEDA) for the International Fusion Materials Irradiation FaciLity (IFMIF) is proceeding as one of the ITER broader approach activities. In the concept of the IFMIF, two 40 MeV deuteron beams are injected into a Liquid Li stream (Li target) flowing at a velocity of 15 m s−1. The EVEDA Li test loop (ELTL) is aimed at vaLidating the hydrauLic stabiLity of the Li target at a velocity up to 20 m s−1 under a vacuum condition of 10−3 Pa as the most important issue. Construction of the ELTL, which is the largest Liquid metal loop possessing 5.0 m3 Li for the fusion research ever, was completed in the O-arai Research & Development Center in the Japan Atomic Energy Agency on 22 November 2010. This paper presents the design and fabrication technology of a target assembly called integrated target assembly, in which the Li target is produced by a contraction nozzle along a concave channel. There are two concepts regarding the target assembly: the integrated target assembly and the bayonet target assembly. Both target assembLies are outLined in this paper, and then the newly proposed design of the integrated target assembly for the ELTL and its fabrication technology are given. The integrated target assembly was processed by a five-axis milLing machine and the processing accuracy was measured by 3D measurement tools. Finally, methods appLied for the vaLidation of the stabiLity of the Li target are introduced in this paper.

  • thickness distribution of high speed free surface Lithium flow simulating ifmif target
    Symposium On Fusion Technology, 2009
    Co-Authors: Hiroo Kondo, Mizuho Ida, Hiroo Nakamura, Takuji Kanemura, Nobuo Yamaoka, Hirokazu Sugiura, S Miyamoto, Izuru Matsushita, T Muroga, H Horiike
    Abstract:

    Abstract International Fusion Materials Irradiation FaciLity (IFMIF) employs Liquid Lithium as D+ beams target. The Liquid Li target is formed as flat plane free-surface flow by a nozzle and flows at high speed around 15 m/s. This paper focuses on flatness of the Liquid Li target. The Li flow experiment was conducted in Osaka University Li Loop with a test section which was 1/2.5 scaled model of IFMIF. The thickness of the Li flow was measured and obtained by a contact method which was developed for the measurement. Analytical study on Kelvin wake and numerical calculation on the wake near the side wall of the flow channel were also conducted and compared with the experimental results. As a result, the positions of the wake crest obtained from both of the experiment and numerical calculation assuming contact angle 140° agreed well with the iso-phase Line of the analytical model. The generation of the wake Likely depends on wettabiLity between Li and the structural material which is 304SS in the present study.

Nobuo Yamaoka - One of the best experts on this subject based on the ideXlab platform.

  • ifmif eveda Lithium test loop design and fabrication technology of target assembly as a key component
    Nuclear Fusion, 2011
    Co-Authors: Hiroo Kondo, Tomohiro Furukawa, Yasushi Hirakawa, Kazuyuki Nakamura, K Watanabe, Takuji Kanemura, E Wakai, H Horiike, Nobuo Yamaoka, Hirokazu Sugiura
    Abstract:

    The engineering vaLidation and engineering design activity (EVEDA) for the International Fusion Materials Irradiation FaciLity (IFMIF) is proceeding as one of the ITER broader approach activities. In the concept of the IFMIF, two 40 MeV deuteron beams are injected into a Liquid Li stream (Li target) flowing at a velocity of 15 m s−1. The EVEDA Li test loop (ELTL) is aimed at vaLidating the hydrauLic stabiLity of the Li target at a velocity up to 20 m s−1 under a vacuum condition of 10−3 Pa as the most important issue. Construction of the ELTL, which is the largest Liquid metal loop possessing 5.0 m3 Li for the fusion research ever, was completed in the O-arai Research & Development Center in the Japan Atomic Energy Agency on 22 November 2010. This paper presents the design and fabrication technology of a target assembly called integrated target assembly, in which the Li target is produced by a contraction nozzle along a concave channel. There are two concepts regarding the target assembly: the integrated target assembly and the bayonet target assembly. Both target assembLies are outLined in this paper, and then the newly proposed design of the integrated target assembly for the ELTL and its fabrication technology are given. The integrated target assembly was processed by a five-axis milLing machine and the processing accuracy was measured by 3D measurement tools. Finally, methods appLied for the vaLidation of the stabiLity of the Li target are introduced in this paper.

  • ifmif eveda Lithium test loop design and fabrication technology of target assembly as a key component
    Nuclear Fusion, 2011
    Co-Authors: Hiroo Kondo, Mizuho Ida, Tomohiro Furukawa, Yasushi Hirakawa, Kazuyuki Nakamura, K Watanabe, Takuji Kanemura, E Wakai, H Horiike, Nobuo Yamaoka
    Abstract:

    The engineering vaLidation and engineering design activity (EVEDA) for the International Fusion Materials Irradiation FaciLity (IFMIF) is proceeding as one of the ITER broader approach activities. In the concept of the IFMIF, two 40 MeV deuteron beams are injected into a Liquid Li stream (Li target) flowing at a velocity of 15 m s−1. The EVEDA Li test loop (ELTL) is aimed at vaLidating the hydrauLic stabiLity of the Li target at a velocity up to 20 m s−1 under a vacuum condition of 10−3 Pa as the most important issue. Construction of the ELTL, which is the largest Liquid metal loop possessing 5.0 m3 Li for the fusion research ever, was completed in the O-arai Research & Development Center in the Japan Atomic Energy Agency on 22 November 2010. This paper presents the design and fabrication technology of a target assembly called integrated target assembly, in which the Li target is produced by a contraction nozzle along a concave channel. There are two concepts regarding the target assembly: the integrated target assembly and the bayonet target assembly. Both target assembLies are outLined in this paper, and then the newly proposed design of the integrated target assembly for the ELTL and its fabrication technology are given. The integrated target assembly was processed by a five-axis milLing machine and the processing accuracy was measured by 3D measurement tools. Finally, methods appLied for the vaLidation of the stabiLity of the Li target are introduced in this paper.

  • thickness distribution of high speed free surface Lithium flow simulating ifmif target
    Symposium On Fusion Technology, 2009
    Co-Authors: Hiroo Kondo, Mizuho Ida, Hiroo Nakamura, Takuji Kanemura, Nobuo Yamaoka, Hirokazu Sugiura, S Miyamoto, Izuru Matsushita, T Muroga, H Horiike
    Abstract:

    Abstract International Fusion Materials Irradiation FaciLity (IFMIF) employs Liquid Lithium as D+ beams target. The Liquid Li target is formed as flat plane free-surface flow by a nozzle and flows at high speed around 15 m/s. This paper focuses on flatness of the Liquid Li target. The Li flow experiment was conducted in Osaka University Li Loop with a test section which was 1/2.5 scaled model of IFMIF. The thickness of the Li flow was measured and obtained by a contact method which was developed for the measurement. Analytical study on Kelvin wake and numerical calculation on the wake near the side wall of the flow channel were also conducted and compared with the experimental results. As a result, the positions of the wake crest obtained from both of the experiment and numerical calculation assuming contact angle 140° agreed well with the iso-phase Line of the analytical model. The generation of the wake Likely depends on wettabiLity between Li and the structural material which is 304SS in the present study.

H Horiike - One of the best experts on this subject based on the ideXlab platform.

  • measurement of transient flow characteristics of target flow in water experiment for ifmif
    Fusion Engineering and Design, 2017
    Co-Authors: Shotaro Matsuda, Hiroo Kondo, Takuji Kanemura, Sachiko Yoshihashi, Eiji Hoashi, Takafumi Okita, Sayaka Kaji, H Horiike
    Abstract:

    Abstract International Fusion Material Irradiation FaciLity (IFMIF) is the faciLity generating the high flux and high energy neutrons to develop fusion reactor materials. In IFMIF, high-speed Liquid Lithium (Li) jet is used as the target irradiated by deuteron beams. Since the Li jet must flow with high velocity for heat removal, it is important to research on the Li flow characteristics. These researches have been aimed toward the steady-state Li flow characteristics. On the other hand, in the actual IFMIF, it is also necessary to clarify transient flow characteristics at start and stop of the system for the operation. In this study, water experiment to obtain them at start and stop is thus conducted. Water can be substituted for Liquid Li as the target, because the kinematic viscosity of the Li at operation temperature in IFMIF is nearly equal to that of water at normal temperature and pressure. Flow patterns of the water jet at test section which consists of a two-staged contraction nozzle, a vertical concave flow channel are observed by laser probe method and high-speed video camera. As a result, the flow pattern at start and stop was successfully observed. The flow at stop became stable by venting gas.

  • Liquid Li based neutron source for bnct and science appLication
    Applied Radiation and Isotopes, 2015
    Co-Authors: H Horiike, Isao Murata, Toshiyuki Iida, Sachiko Yoshihashi, Eiji Hoashi, Itsuro Kato, Naoya Hashimoto, Shuhei Kuri, S Oshiro
    Abstract:

    Liquid Lithium (Li) is a candidate material for a target of intense neutron source, heat transfer medium in space engines and charges stripper. For a medical appLication of BNCT, epithermal neutrons with least energetic neutrons and γ-ray are required so as to avoid unnecessary doses to a patient. This is enabled by Lithium target irradiated by protons at 2.5 MeV range, with utiLizing the threshold reaction of (7)Li(p,n)(7)Be at 1.88 MeV. In the system, protons at 2.5 MeV penetrate into Li layer by 0.25 mm with dissipating heat load near the surface. To handle it, thin film flow of high velocity is important for stable operation. For the proton accelerator, electrostatic type of the Schnkel or the tandem is planned to be employed. Neutrons generated at 0.6 MeV are gently moderated to epithermal energy while suppressing accompanying γ-ray minimum by the dedicated moderator assembly.

  • ifmif eveda Lithium test loop design and fabrication technology of target assembly as a key component
    Nuclear Fusion, 2011
    Co-Authors: Hiroo Kondo, Tomohiro Furukawa, Yasushi Hirakawa, Kazuyuki Nakamura, K Watanabe, Takuji Kanemura, E Wakai, H Horiike, Nobuo Yamaoka, Hirokazu Sugiura
    Abstract:

    The engineering vaLidation and engineering design activity (EVEDA) for the International Fusion Materials Irradiation FaciLity (IFMIF) is proceeding as one of the ITER broader approach activities. In the concept of the IFMIF, two 40 MeV deuteron beams are injected into a Liquid Li stream (Li target) flowing at a velocity of 15 m s−1. The EVEDA Li test loop (ELTL) is aimed at vaLidating the hydrauLic stabiLity of the Li target at a velocity up to 20 m s−1 under a vacuum condition of 10−3 Pa as the most important issue. Construction of the ELTL, which is the largest Liquid metal loop possessing 5.0 m3 Li for the fusion research ever, was completed in the O-arai Research & Development Center in the Japan Atomic Energy Agency on 22 November 2010. This paper presents the design and fabrication technology of a target assembly called integrated target assembly, in which the Li target is produced by a contraction nozzle along a concave channel. There are two concepts regarding the target assembly: the integrated target assembly and the bayonet target assembly. Both target assembLies are outLined in this paper, and then the newly proposed design of the integrated target assembly for the ELTL and its fabrication technology are given. The integrated target assembly was processed by a five-axis milLing machine and the processing accuracy was measured by 3D measurement tools. Finally, methods appLied for the vaLidation of the stabiLity of the Li target are introduced in this paper.

  • ifmif eveda Lithium test loop design and fabrication technology of target assembly as a key component
    Nuclear Fusion, 2011
    Co-Authors: Hiroo Kondo, Mizuho Ida, Tomohiro Furukawa, Yasushi Hirakawa, Kazuyuki Nakamura, K Watanabe, Takuji Kanemura, E Wakai, H Horiike, Nobuo Yamaoka
    Abstract:

    The engineering vaLidation and engineering design activity (EVEDA) for the International Fusion Materials Irradiation FaciLity (IFMIF) is proceeding as one of the ITER broader approach activities. In the concept of the IFMIF, two 40 MeV deuteron beams are injected into a Liquid Li stream (Li target) flowing at a velocity of 15 m s−1. The EVEDA Li test loop (ELTL) is aimed at vaLidating the hydrauLic stabiLity of the Li target at a velocity up to 20 m s−1 under a vacuum condition of 10−3 Pa as the most important issue. Construction of the ELTL, which is the largest Liquid metal loop possessing 5.0 m3 Li for the fusion research ever, was completed in the O-arai Research & Development Center in the Japan Atomic Energy Agency on 22 November 2010. This paper presents the design and fabrication technology of a target assembly called integrated target assembly, in which the Li target is produced by a contraction nozzle along a concave channel. There are two concepts regarding the target assembly: the integrated target assembly and the bayonet target assembly. Both target assembLies are outLined in this paper, and then the newly proposed design of the integrated target assembly for the ELTL and its fabrication technology are given. The integrated target assembly was processed by a five-axis milLing machine and the processing accuracy was measured by 3D measurement tools. Finally, methods appLied for the vaLidation of the stabiLity of the Li target are introduced in this paper.

  • thickness distribution of high speed free surface Lithium flow simulating ifmif target
    Symposium On Fusion Technology, 2009
    Co-Authors: Hiroo Kondo, Mizuho Ida, Hiroo Nakamura, Takuji Kanemura, Nobuo Yamaoka, Hirokazu Sugiura, S Miyamoto, Izuru Matsushita, T Muroga, H Horiike
    Abstract:

    Abstract International Fusion Materials Irradiation FaciLity (IFMIF) employs Liquid Lithium as D+ beams target. The Liquid Li target is formed as flat plane free-surface flow by a nozzle and flows at high speed around 15 m/s. This paper focuses on flatness of the Liquid Li target. The Li flow experiment was conducted in Osaka University Li Loop with a test section which was 1/2.5 scaled model of IFMIF. The thickness of the Li flow was measured and obtained by a contact method which was developed for the measurement. Analytical study on Kelvin wake and numerical calculation on the wake near the side wall of the flow channel were also conducted and compared with the experimental results. As a result, the positions of the wake crest obtained from both of the experiment and numerical calculation assuming contact angle 140° agreed well with the iso-phase Line of the analytical model. The generation of the wake Likely depends on wettabiLity between Li and the structural material which is 304SS in the present study.