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• The blanket testing facility for WCCB TBM was newly built in Rokkasho Fusion Institute, Japan. • An apparatus for flow accelerated corrosion testing under coolant condition of TBM was installed. • An apparatus for high heat flux testing under cooling with pressurized water using electron beam gun was installed. • An apparatus for ingress testing of pressurized water inside TBM was installed. • An apparatus for evaluating characteristics of beryllium-water reaction was installed. Intensive research and development activities have been conducted for designing a water-cooled ceramic breeder (WCCB) blanket system. In this system 325 °C/15.5 MPa of pressurized water removes heat injected and accumulated in blanket containers made of a reduced activation ferritic/martensitic steel, F82H. The container has lithium ceramics and beryllium pebbles as tritium breeder and neutron multiplier, respectively. In order to demonstrate performance of the system, especially for high-temperature pressurized water coolant, experimental apparatus have been installed in Rokkasho Fusion Institute, National Institutes for Quantum Science and Technology, Japan. These apparatuses enable to conduct the following experiment on full-scale mockups: 1) high heat flux (HHF) test to demonstrate heat removal of surface heat flux by electron beam gun simulating plasma, 2) flow assisted corrosion, 3) coolant ingress into dummy pebble beds, and 4) beryllium-water reaction between the coolant and the pebbles. In this paper, overviews, specifications, early results of these apparatus are reported. [ABSTRACT FROM AUTHOR]

This study experimentally investigates the efficacy of TE11 mode microwaves in detecting bend-region cracks. Three types of bends with different dimensions were deployed in a 3 m piping system and then tested, with an axial or circumferential slit machined at different angular positions to simulate a crack. The TE11 mode microwaves were excited using self-designed TE11 mode microwave probes and utilised for crack detection. The experimental results show clear reflection peaks at the bend position, demonstrating the feasibility of applying TE11 mode microwaves in the detection of bend-region cracks. Furthermore, the peak location of reflection is in accordance with the angular position of the slit. The findings also indicate that the peak amplitude of reflection is affected by the factors of mode conversion of microwaves at a bend. In addition, the experimental results also manifest an excellent signal-to-noise ratio to both two types of slits, suggesting that the microwave NDT is a powerful tool for bend-region inspection. [ABSTRACT FROM AUTHOR]

We analytically and numerically study quasinormal frequencies (QNFs) of neutral and charged scalar fields in the charged anti-de Sitter (AdS) black holes and discuss the stability of the black holes in terms of the QNFs. We focus on the range of the mass squared μ2 of the scalar fields for which the Robin boundary condition parametrized by ζ applies at the conformal infinity. We find that if the black hole of radius r+ and charge Q is much smaller than the AdS length ℓ, the instability of the charged scalar field can be understood in terms of superradiance in the reflective boundary condition. Noting that the s-wave normal frequency in the AdS spacetime is a decreasing function of ζ, we find that if |eQ|ℓ/r+ is greater than , where e is the charge of the scalar field, the black hole is superradiantly unstable irrespectively of ζ. On the other hand, if |eQ|ℓ/r+ is equal to or smaller than this critical value, the stability crucially depends on ζ and there appears a purely oscillating mode at the onset of the instability. We argue that as a result of the superradiant instability, the scalar field gains charge from the black hole and energy from its ambient electric field, while the black hole gives charge to the scalar field and gains energy from the scalar field but decreases its asymptotic mass parameter. [ABSTRACT FROM AUTHOR]

In this study, a TE01 mode converter was developed to locate an axial crack on the inner surface of a metal pipe. Three-dimensional finite element simulation was conducted to evaluate the effect of inserted coaxial cables on the transmission characteristic of the mode converter. The result showed that the energy of TE mode microwaves leaned to transmit to one side when the cables penetrated with inclination. To demonstrate the effectiveness of the mode converter, experimental verification was conducted. The mode converter was fabricated based on the simulation result. Microwaves were emitted through the pipe wall of the converter to propagate on both sides ('right side' and 'left side') of a pipe with an artificial slit. Compared with the signals from each side, the reflection from the slit on the right side was more significant than that on the left side. This result is consistent with the numerical simulation result. [ABSTRACT FROM AUTHOR]

This study evaluated the effect of pipe diameter on the applicability of a technique using TE11 mode microwaves for in-pipe crack detection. Three TE11 mode converters of different inner diameters were designed based on theoretical calculations and verified via numerical simulations. The working bandwidths of these mode converters were 7.0, 4.0, and 1.9 GHz. Experimental verification was carried out using brass pipes with the corresponding three inner diameters, and with pipe lengths up to 21–25.5 m. An axial and a circumferential slit were introduced to simulate cracks and deployed at multiple positions along the pipes under test. The results showed that both axial and circumferential slits could be detected and located for an inner pipe diameter up to 39 mm and at a distance of 15 m–24 m. [ABSTRACT FROM AUTHOR]

This study discusses the characteristics of a mode converter to generate microwaves in the TE01 mode for the long-range inspection of pipes. Numerical analysis was conducted to evaluate the effect of the pipe diameter and the number of coaxial cables inserted into the pipe on the efficiency of converting microwaves from the coaxial TEM mode to the circular TE01 mode. The results reveal that the most efficient frequency range for TE01 mode propagation strongly depends on the number of cables and pipe diameter. Subsequent experiments were performed using brass pipes with a length of 5 m and diameters of 39.0 and 74.0 mm. The results of these experiments are consistent with the results of the numerical analysis: the pipe with a diameter of 39.0 mm showed a clear signal from an axial slit 1.5 m away from the mode converter and the pipe with a diameter of 74.0 mm showed almost no difference between signals with or without the slit. [ABSTRACT FROM AUTHOR]

Since the submodules as the most important structural component in Water-Cooled Ceramic Breeder (WCCB) Test Blanket Module (TBM) contributes to tritium breeding and extracting, structural integrity assessment is necessary to keep normal operation and function of WCCB TBM-set. Recently, the nonirradiated material properties of F82H which is considered as the structural material of submodule has been summarized following the requirement of RCC-MRx, combined with EU directive, French order, and pressure vessel construction code (RCC-MRx), structural integrity assessment is investigated under the ITER relevant thermo-mechanical load in this study. Meanwhile, cooling water conditions of WCCB TBM-set with its operation scenario, relationship, and detailed values (temperature and pressure) are constituted. Based on the determined structural integrity assessment procedure from RCC-MRx and numerical analysis results, structural integrity of current design of submodule in WCCB TBM-set could be validated. According to the current achievements and established structural integrity assessment procedure, further evaluation on structural integrity combined with electromagnetic load shall be investigated. [ABSTRACT FROM AUTHOR]

This study demonstrated the applicability of a nondestructive microwave testing method for the long-range inspection of pipe inner surfaces. Experimental verifications were conducted using pipes with lengths of 19–26.5 m, inner diameters of 11, 19, or 39 mm, and made of either brass or austenitic stainless steel. Microwaves were emitted from a probe attached to one of the pipe ends, and the reflections due to full circumferential wall thinning 50 mm in length and 1 mm in depth situated at various distances from the end were measured. The frequency range and the probe characteristics were decided so that microwaves propagating only in TM 01 mode affect signals. After signal processing to compensate for microwave dispersion, the measured signals showed clear reflections caused by wall thinning situated 23.5 m from the pipe end at which microwaves were emitted. This study also discussed the attenuation of microwave reflection with the distance between a probe and wall thinning. The experimental results agreed well with a theoretical model describing the attenuation of microwave propagating inside a pipe, although the model did not consider the reflection of microwaves due to a flaw, the dependence of the reflection on the frequency of microwaves, or mode conversion of the microwave due to the reflection. The agreement revealed that not only frequency but also the inner diameter, electromagnetic property, and surface roughness of a pipe are needed to evaluate the length of the pipe that can be inspected by the method. [ABSTRACT FROM AUTHOR]

We study hairy black holes in Einstein-Maxwell-complex scalar theory in four-dimensional asymptotically global anti-de Sitter (AdS) spacetime when the Robin boundary conditions are imposed on the scalar field. This setup is dual to the double trace deformation of strongly interacting field theory on R × S2 by charged scalar operators. We identify the instability of the Reissner-Nordström-AdS (RNAdS) black holes under the Robin boundary conditions and construct backreacted geometries branching at the onset of the instability. Also considering associated horizonless geometries called boson stars, we obtain phase diagrams with fairly rich structure in the grand canonical ensemble depending on the boundary condition parameter or the deformation parameter, where phase transition occurs between thermal AdS, RNAdS, charged boson stars, and hairy black holes. [ABSTRACT FROM AUTHOR]

This study investigated the applicability of microwave non-destructive testing, which has been proved effective in quickly detecting the defect location in a long pipe, to the size evaluation of wall thinning defects. Artificial wall thinning defects with different sizes (depths and lengths) and edge profiles were introduced to a flanged brass pipe with a total length of 15 m, and reflected microwave signals were measured in experiments. A signal processing method combining windowing and dispersion compensation was proposed to extract the defect-related reflection signals in the frequency domain. Resonant frequencies, at which the amplitude of extracted signals dropped significantly, decreased with the increase of either wall thinning depth or length. In addition, the results demonstrate that wall thinning location and pipe end conditions have little influence on resonant frequencies after signal processing. A back propagation neural network was trained by simulation data, using resonant frequencies as the input, to simultaneously evaluate defect depth and length, and the performance was validated by experiments. Maximum prediction errors of depth and length of wall thinning were 0.06 mm and 0.57 mm, respectively, which indicated the feasibility of the proposed method to evaluate the wall thinning defect sizes. [ABSTRACT FROM AUTHOR]

• Microwaves in TM 01 mode are useful for detecting multiple thinning defects. • Two defects in a metal pipe were located in a single measurement. • A 1 mm deep flaw does not hamper the detection of other flaws behind that. In this study, the applicability of a nondestructive method using microwaves to the detection of multiple pipe wall thinning defects was investigated. In numerical simulation, a single full circumferential defect was introduced into a straight pipe of 19 mm inner diameter, and the effect of the defect on transmitted waves was investigated. The transmitted energy ratio of the TM 01 mode to the emitted wave was found to be 93% in average even in the presence of a 1-mm depth thinning. After that, experimental measurements were performed using a flanged brass tube with two artificial thinning defects. By applying signal processing to the measured S -parameters, clear reflections from the two defects were observed. By comparing the signals, we confirmed that the first full circumferential defect provides at most 12% amplitude attenuation of the reflected signal from the second defect, which should be related to the distance and size of the defects. [ABSTRACT FROM AUTHOR]

This study investigated the effect of a bend on microwave NDT (non-destructive testing) applied for rapid pipe inspections. The factors affecting the mode conversion of microwaves due to a bend were deducted theoretically and verified through numerical simulation. Both theoretical and numerical results revealed that the mode conversion at a bend was actually determined by the frequency normalized by the cut-off frequency of an arbitrary mode (f / f c), the ratio of the curvature radius to the inner diameter of the pipe (r / D) and the bend angle (α). Subsequent experimental evaluations were performed using four groups of pipes with different inner diameters and five different bends. The effect of a bend was quantitatively evaluated by comparing the reflection signals from pipe wall thinning in a straight pipe with those in a bent pipe. The results showed that the presence of a bend led to a decrease in the reflection signal behind the bend, and the extent of decrease also depended on r / D and α of the bend. Furthermore, the length or the depth of the pipe wall thinning did not noticeably affect the decrease in reflection signal, when the bend's dimensions were certain. [ABSTRACT FROM AUTHOR]

This study proposed a long-range non-destructive pipe inspection approach using linearly-polarized circular TE 11 mode microwaves, enabling rapid detection of both axial and circumferential cracks on the inner surface of a metallic pipe. The applicability of the TE 11 mode microwaves for crack detection was discussed in the light of the currents induced on the inner surface of a pipe due to the propagation of the TE 11 mode microwaves. A dual-bend structured mode converter was designed to propagate linearly-polarized TE 11 mode microwaves inside a pipe with a certain inner diameter, based on the theoretical and numerical analysis of mode conversion due to a bend. A 3.5 GHz working bandwidth of the mode converter was achieved with a conversion efficiency of the TE 11 mode of over 90%. Experimental verification was conducted using stainless-steel pipes with an inner diameter of 23 mm and a total length of 7 m. An axial and a circumferential slit were introduced to simulate cracks. The experimental results confirmed reflections from both the axial and circumferential slits, indicating that the TE 11 mode microwaves are applicable to crack detection. The results also confirmed the correlation between TE 11 mode polarization and its detection sensitivity toward slits with different orientations along the circumferential direction. Furthermore, the axial and circumferential slits situated at different longitudinal and circumferential locations in the pipe were successfully detected by orthogonally deploying the mode converter to change the polarization of the TE 11 mode by 90°. [ABSTRACT FROM AUTHOR]

Intensive research and development activities have been conducted for preliminary design of a water-cooled ceramic breeder (WCCB) blanket system. As a part of these activities, some full scale mockups have been fabricated to verify feasibility, including manufacturing and inspecting procedures. This paper introduces an overview of the recent achievements in the mock-up testing on the WCCB blanket system. A blanket sub-module mockup have been manufactured using a reduced activation ferritic/martensitic steel, F82H with conventional industrial resources. As for water cooling system component, a mock-up of pneumatic isolation valve for DN50 pipe. The valve demonstrated sound operation after vertical and horizontal vibration simulating seismic loads. Moreover, the valve has demonstrated close / open operation in less than three seconds in magnetic field ranging from 290 to 500 mT, and the operation time was not affected by the magnetic field in this range. As for tritium storage device, mockup of ZrCo metal hydrate bed were also manufactured to find show stoppers in application as equipment for tritium extraction system (TES) in the WCCB-blanket system. [ABSTRACT FROM AUTHOR]

This study evaluated the effect of bends on the long-range nondestructive testing inspection of pipe surfaces based on microwaves propagating inside the pipe. Three-dimensional finite element simulations were conducted to reveal electromagnetic fields at bends with a diameter of 23 mm and various radii of curvature when microwaves were emitted into a pipe in the TM01 mode that had been mainly used in earlier studies. The simulations revealed that the effect of the bend on the microwaves is not significant when the ratio of curvature is larger than approximately 2, whereas in general a bend reflects a part of microwaves and causes non-TM01 modes. Subsequent experimental verifications, which used a pipe with a total length of approximately 4 m and a 90-degree or 180-degree bend, confirmed clear reflections due to artificial wall thinning in spite of the presence of the bend. [ABSTRACT FROM AUTHOR]

This paper presents a multivariate probability of detection (POD) analysis method for long-range pipe inspection using microwave non-destructive testing (NDT). The proposed two-dimensional (2D) POD model considers both the size and location of pipe wall thinning (PWT) and is thus able to simultaneously characterize the detectability and detection range. First, the propagation of microwaves in a pipe with PWT was modeled through numerical simulation. The simulated S-parameters (S11) were converted into the time domain and were further processed to correlate the amplitude of the reflection signal with the corresponding PWT depth and location. The simulation results indicate that the logarithmic amplitude of the reflection signal is proportional to the PWT location and logarithmic PWT depth. Therefore, a prior multivariate regression model was established for the above three parameters. Second, an experiment was performed using a 14.5-m-long brass pipe. Twelve short pipes with six different inner diameters were used to emulate PWT and were deployed at eight different locations in the pipe. The experimental results suggest that each PWT can be detected with excellent repeatability, and show consistency with the simulation results. The processed experimental signals were subsequently employed for the regression model of the amplitude of the reflection signal, PWT depth, and location. Finally, a 2D POD model was constructed on the basis of the regression model and a dynamic-static threshold, combining in-pipe microwave signal attenuation with instrumental noises. The POD plot and contour give reasonable interpretations of the detection capability of this testing method against PWTs with different depths, considering the PWT locations. [ABSTRACT FROM AUTHOR]

National institutes for Quantum Science and Technology (QST) are the implementing body of ITER project in Japan and takes the lead in fusion DEMO reactor development in Japan. The primary candidate of the breeder blanket for JA DEMO is Water Cooled Ceramic Breeder (WCCB) blanket. ITER-Test Blanket Module (TBM) program is an opportunity for the demonstration of DEMO breeding blanket concept under actual fusion environment. QST has led the development of the WCCB TBM Concept in the program since the signing of the TBM Arrangement in 2014. The preliminary design of test blanket system (TBS) is on-going. Recently, the status of the preliminary design of TBS was assessed between QST and the ITER Organization (IO). So, the status of the latest TBS design and the DEMO relevancy is presented. [ABSTRACT FROM AUTHOR]

Demonstrates that a novel hematopoietic adaptor protein, Chat-H, positively regulates T cell receptor-mediated interleukin-2 production by Jurkat cells. Molecular cloning of Chat-H; Enhancement of the degree of JNK activation in the Chat-H transfectants upon costimulation; Finding that Chat-H forms a complex with Pyk2H and enhances its tyrosine 403 phosphorylation; Indication that Chat-H positively controls T cell function via integrating the costimulatory signals.