記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：IEEE Transactions on Applied Superconductivity  

A superconducting synchronous motor designed for operation in persistent current mode (PCM) is being developed. A persistent current switch (PCS) is required for PCM operation to connect the field coil in parallel. We propose a PCS constructed from REBa<inf>2</inf>Cu<inf>3</inf>O<inf>y</inf> (REBCO) tapes without copper-stabilized layers. We fabricated and tested a PCS using these REBCO tapes to evaluate magnetic field decay during PCM operation. The results confirm that the PCS does not degrade. The fabrication process encountered challenges owing to the absence of stabilized layers, including potential degradation from silver diffusion into the solder and moisture penetration into the superconducting layer. Therefore, copper plating was selectively applied to the soldering area, and the PCS was encapsulated in epoxy resin. The effectiveness of these measures was verified by measuring the V-I characteristics of the copper-plated REBCO tape over several days, along with the V-I characteristics of the PCS. Neither the copper-plated REBCO tapes nor the PCS showed degradation after ten days. A double-pancake coil designed for PCM operation was fabricated using REBCO tapes with stabilized layers, considering 1% magnetic field decay over 10 min. During PCM operation, the time constant of the PCS aligned with the calculated value, and no degradation was observed.

DOI： 10.1109/TASC.2024.3518456

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担当区分：筆頭著者   記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1109/TASC.2024.3518453

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：IEEE Transactions on Applied Superconductivity  

Aircraft equipment needs to maintain stable operation in low-temperature and low-pressure environments. This study assesses the feasibility of operating a developed machine under such conditions. Rotational tests were conducted in an environment that simulated the conditions required for aircraft-mounted equipment. The synchronous machine was installed in a thermostatic chamber that was set to a temperature of -55 °C and pressure of 11 kPa, which mimics the conditions at an altitude of 15,000 m. The machine demonstrated stable operation at a rotational speed of 180 rpm, with a field current of 50 A and an armature current amplitude of 100 A at a frequency of 3 Hz. The synchronous machine was tested in generator mode at ground level under no-load and three-phase short-circuit conditions to evaluate its rated operation under a normal environment. In the no-load test, the field current and rotational speed were increased from 10 A to 110 A and 100 rpm to 2,500 rpm, respectively, and the maximum line voltage was 590 V. In the three-phase short-circuit test, the U, V, and W phases exhibited maximum short-circuit currents of 490 A with a field current of 45 A and rotational speed of 100 rpm. These results confirm that the synchronous machine operated stably at 2,500 rpm with an output of 250 kW in generator mode. The stable performance of the machine under these conditions suggests its potential for enhancing the efficiency, power density, and reliability of electric propulsion systems in aviation.

DOI： 10.1109/TASC.2024.3520532

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1109/TASC.2025.3525599

出版者・発行元：International Journal on Magnetic Particle Imaging  

In this work, the fundamental imaging performance of the developed high temperature superconductor (HTS) MPI system with 120 mm bore diameter was investigated. The full width at half maximum, which is related to the spatial resolution of the image, was 30 mm under the gradient field of 0.34 T/m. Note that the gradient field can be easily increased by increasing the number of turns of the HTS selection field coils since the power consumption and the mass of the HTS coils are very low. The reasonable limit of detection of 48 µg(Fe) was also obtained. Since the power consumption and the mass of MPI scanner can be dramatically reduced by using HTS tape compared with those made of Cu wire, a HTS MPI scanner is one of the promising candidates for the realization of human-body-sized MPI scanner.

DOI： 10.18416/ijmpi.2025.2503018

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：IEEE Transactions on Applied Superconductivity  

AC loss is a common challenge in superconducting AC applications that increases the temperature and causes quenching, and therefore, it is crucial to reduce the AC loss. Multifilament tapes fabricated via a new method that can create a low critical current density region in the superconducting layer by scratching a buffer layer to make it multifilamentary has been proposed. However, these tapes are not completely insulated. Few studies have compared the measured AC losses of coils wound with multifilament and monofilament tapes and identified whether scaling laws are adaptable to multifilament tapes. In this study, we measure the AC losses of multifilament tapes under various conditions, such as with thinner copper layers and two-stacked pancake coils wound with them, to examine the effect of electrical coupling using a copper plate and confirm the AC loss reduction effect, respectively. These tapes are not physically separated from each other, and therefore, the AC loss is measured by varying the number of coils turns. We investigate whether the scaling laws are applicable to the multifilament tapes. The results confirm that coupling loss is present; however, the AC loss for B > 0p (B and Bp represent the external magnetic field amplitude and the magnet field amplitude when it penetrates the superconducting layer, respectively) is reduced sufficiently. Further, the temperature and field angle scaling law can be adapted to this multifilament tape. The AC losses of the coils wound with monofilament and multifilament tapes did not show any significant differences when the number of turns was changed.

DOI： 10.1109/TASC.2024.3370097

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：IEEE Transactions on Applied Superconductivity  

—Armature coils that use REBa2Cu3Oy (REBCO) wires are typically racetrack shaped owing to the tape shape of the wires. It is difficult to improve the motor output in armature windings composed of racetrack coils. Previously, we proposed trapezoidal-shaped REBCO coils for armature windings. In this study, we perform electromagnetic simulations of two types of induction motors with armature windings, one composed of trapezoidal coils and the other of racetrack coils. Subsequently, we show that the induction motor using trapezoidal coils exhibit a higher output than that using racetrack coils. Moreover, we present the fabrication of six trapezoidal coils for use in the armature winding and present the current-voltage (I − V ) characteristics of the coils to determine the current flow. The results show that a current of 80 A or higher could flow in all the coils. Finally, we present the results from a load test of an induction motor that incorporates the trapezoidal coils for the armature winding and the corresponding torque slip characteristics. The analysis and load test results are comparable, thus experimentally demonstrating the effectiveness of using trapezoidal coils for armature windings to increase the motor output.

DOI： 10.1109/TASC.2023.3345300

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：IEEE Transactions on Applied Superconductivity  

Advanced electric propulsion systems have been developed by utilizing superconducting technologies to reduce carbon dioxide emissions from aircraft. This study presents the progress in the development of a 400 kW-class fully superconducting synchronous motor using REBa2Cu3O7-δ (REBCO) tape. REBCO tapes have high critical current densities; thus, they can generate a strong magnetic field without an iron core, permitting the fabrication of small-sized motors compared with conventional motors that use copper wires and iron cores. The 400 kW-class fully superconducting synchronous motor comprises field and armature coils. The field coil was wound with cos-theta-like racetrack distribution to generate a dipole field without an iron core. The maximum magnetic field is 1.45 T when the operating current is 110 A DC. The armature coil comprises six racetrack-shaped pancakes wound with six-strand parallel conductors. The parallel conductors were transposed inside the windings, resulting in a uniform current distribution in each conductor. The motor utilized carbon fiber-reinforced plastic (CFRP) for the casing instead of stainless steel for weight reduction. Foam insulation was adopted to further reduce the mass, in which an adiabatic material was wrapped around the external part of the CFRP casing. The armature coil was cooled using sub-cooled liquid nitrogen (LN2), with high electrical insulation and a stable liquid phase. In contrast, the field coil was cooled by utilizing helium gas instead of LN2 because sealing the LN2 with a magnetic fluid seal is challenging. The motor was tested in a synchronous generator mode and subsequently rotated by utilizing three bipolar power supplies. The motor successfully rotated at 441 rpm when the field current was 72 A, the armature current was 103 Arms, and the frequency was 7.35 Hz.

DOI： 10.1109/TASC.2023.3345291

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：IEEE Transactions on Applied Superconductivity  

Fully superconducting synchronous motors are very interesting for mobile applications such as aviation, thanks to their high output power density (kW/kg). In order to obtain a large current capacity, multi-strand parallel conductors are usually used in armature coils but parallel conductors without transposition present non-uniform current sharing. In this manuscript, current sharing properties among three REBa2Cu3Oy parallel tapes with/without a transposition in three-phase armature coil conditions, were investigated experimentally and analytically. The sample coils were prepared under the three-phase arrangement of armature coils for a two-pole rotating machine, and its branch currents were evaluated by Rogowski coils by applying AC transport current in liquid nitrogen at 77 K. We demonstrated that the introduction of the transposition was also an effective way to control the current sharing in rotating magnetic fields generated by the three-phase armature coils as well as single-phase situations. In addition, the influence of other phase armature coils on the current sharing was discussed via analytical calculations.

DOI： 10.1109/TASC.2024.3352521

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：IEEE Transactions on Applied Superconductivity  

An electric propulsion system is one of the solutions to achieve low carbon dioxide emissions from aircraft. In this regard, a superconducting motor is being developed to achieve higher power density than conventional motors. Because a REBa2Cu3O7-σ (REBCO) wire is difficult to bend freely owing to its tape shape, racetrack windings are often used for the armature coils of the superconducting motors. Although the output power can be increased for the same armature current by widening the armature winding pitch angle, the racetrack armature has only a small pitch of 30°. A full-pitched armature with the maximum pitch angle has not been realized in past studies. Therefore, in this study, we propose an unprecedented configuration method of a four-pole full-pitched armature coil composed of trapezoidal windings. To investigate the advantages of the armature, we made a 2D cross-sectional model and determined torque using the finite element method of electromagnetic field analysis. Consequently, we verified that the trapezoidal four-pole armature had lower torque ripple and higher power density than the conventional two-pole racetrack armature. This study confirmed that the proposed novel armature had better characteristics than conventional ones. The armature can make the motor lightweight and low-noise.

DOI： 10.1109/TASC.2024.3358250

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：IEEE Transactions on Applied Superconductivity  

We propose transposed parallel conductors that can equalize the current distribution in the coils of a superconducting motor with an armature winding imitating a distributed winding using REBa2Cu3Oy(REBCO) tapes. However, AC loss increases the coil temperature, resulting in a quench. A striated REBCO tape with a filament divided into multiple filaments can effectively reduce AC loss. We measured the current flow distribution in the coils using transposed parallel conductors composed of striated REBCO tapes. Additionally, we experimentally demonstrate current equalization based on the transposition of the previous armature winding using only a small coil. We arranged two REBCO tapes side-by-side to simulate a striated tape divided into two filaments. The double-pancake coils in the armature coils were wound with the striated tapes and transposed at the connection point between each pole and the innermost circumference of the coils. We measured and verified the inductance of each tape. Additionally, we measured the current distributions for both U- and three-phase current flows.

DOI： 10.1109/TASC.2024.3356439

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担当区分：筆頭著者,　責任著者   記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）  

<title>Abstract</title>
In this study, we focused on the dependence of the AC loss in REBa₂Cu₃O#D
<italic>y</italic>
#DR (REBCO, RE = rare earth, Y, Eu, Gd) superconducting tapes stacked perpendicular to the tape face on the interval between the superconducting layers. The AC loss of the 2-layer stacked tapes with various interval in perpendicular field was investigated by pickup-coil method. The AC loss for external applied magnetic field, <italic>B</italic>
_m, below the penetration field, <italic>B</italic>
_p, increases with increasing the interval. In the case that the ratio of the distance between the neighboring superconducting layer, <italic>D</italic>, to the width of the tape, <italic>w</italic>, (<italic>D</italic>/<italic>w</italic>) is smaller than 0.1, the AC loss of 2-layer tapes decreased to 1/2 of that of 1-layer tape. On the other hand, in the case of <italic>D</italic>/<italic>w</italic> being larger than 0.1, the AC loss of 2-layer tapes was larger than 1/2 and it approached the AC loss of 1-layer tape with increasing <italic>D</italic>/<italic>w</italic>. From the result obtained in this study, it is predicted that, for <italic>B</italic>
_m below <italic>B</italic>
_p, the AC loss of stacked REBCO tapes with large <italic>D</italic>/<italic>w</italic>, such as multifilamentary tapes, is larger than the AC loss of stacked non-scribed REBCO tapes. However, for <italic>B</italic>
_m above <italic>B</italic>
_p: a large AC loss region, it is known that the AC loss of the multifilamentary tapes decreases compared with that of non-scribed tapes. Next step, AC loss of the multifilamentary tapes for <italic>B</italic>
_m below <italic>B</italic>
_p will be investigated experimentally and theoretically.

DOI： 10.1088/1742-6596/2776/1/012003

担当区分：最終著者   記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）   出版者・発行元：Journal of Physics Conference Series  

The global demand for aircraft is currently increasing, paralleled by a growing emphasis on decarbonization through the replacement of fossil fuel engines with electric propulsion. In response to this trend, we have developed a superconducting motor distinguished by its high efficiency, output, and low weight. Our focus centers on two critical aspects. Firstly, we addressed the issue of the field coil's shape. The widely used REBCO wire in high-temperature superconductivity is tape-shaped, making a racetrack coil the most straightforward method for winding the wire. However, this configuration necessitates dividing the motor shaft as it comes in contact with the field coil, raising concerns about the mechanical durability of motors. To overcome this challenge, we introduce a saddle-type coil and design a coil shape that achieves a single continuous through-axis. Utilizing the Frenet-Serre formula, we created a 3D model of the coil's end without applying load to the wire. This method, previously employed in accelerators, enhances durability, potentially leading to increased output due to higher rotation speeds and reduces weight through part savings. Secondly, introducing a saddle coil presents challenges in forming an ideal magnetic field distribution. In a rotating-field-type motor using an iron core, the winding can be directly wound around it, resulting in multiple coils forming similar magnetic fields that can be superimposed to create one large magnetic pole. However, with a saddle coil, coils are arranged along the circumference, and the magnetic field distribution and an anticipated decrease in output. To address this, we aimed to optimize the magnetic field distribution and increase output through a parameter survey. Specifically, we conducted an analysis under fixed armature conditions (current, number of turns, and shape) in three cases. In Case1, with a fixed total number of turns for the field coil, we compared magnetic field distributions and output by varying the number and arrangement of coils. In Case2, building on the findings of Case1, we aimed to enhance output by fixing the coil arrangement and increasing the number of turns. Finally, in Case 3, we examined the change in motor size with fixed coil parameters while altering the coil arrangement and pitch.

DOI： 10.1088/1742-6596/2776/1/012012

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：IEEE Transactions on Applied Superconductivity  

Fully superconducting synchronous motors employing superconducting armature and field coils, have a great possibility for electric propulsion systems in aircraft applications, owing to their high output power density (kW/kg). To realize a large current capacity in REBa2Cu3Oy superconducting armature coils, we have proposed a cabling design for the transposed multi-strand parallel conductors. In this study, branch currents among eight- and 16-strand parallel conductors having only one transposition into a coil, were investigated. The analytical calculations showed approximately uniform branch current for the eight- and 16-strand conductors. According to the calculations, the deviations to the uniform branch current of eight-strand parallel conductors were ±7%. The approximately uniform current for the eight-strand conductors were also demonstrated experimentally by small-sized sample coils.

DOI： 10.1109/TASC.2024.3356436

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：IEEE Transactions on Applied Superconductivity  

We propose the concept of uniform current between groups (CUCG) in superconducting armature coils composed of two or more strands of transposed parallel conductors. We validate the proposed concept by measuring the current distributions in several double pancake test coils comprising two and four parallel conductors using Rogowski coils by applying AC signals of varying frequencies and amplitudes. Accordingly, uniform transport currents across four strands were confirmed. The proposed concept produced uniform current distributions across four groups of parallel conductors with a small number of transpositions. This work paves the way for developing armature coils composed of more than eight strands in parallel conductors by introducing a small number of transpositions based on CUCG.

DOI： 10.1109/TASC.2023.3242621

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：IEEE Transactions on Applied Superconductivity  

We are currently developing superconducting electric propulsion armature coils which utilize REBa2Cu3Oy (REBCO) strands. To implement the REBCO coils in aircraft, the voltage must be reduced for safety concerns by using high-current capacity. Parallel conductors can be used to expand the current capacity, but the current cannot flow equally through each strand owing to the slight difference in inductance. We have investigated transposed parallel conductors which can almost equalize the inductance of each conductor. Conversely, the distributed windings for the armature coils can improve the magnetic field waveform and transform it into a sine wave by reducing the distortion of the magnetic flux density about the rotating magnetic field. However, it is difficult to implement a distributed armature winding using the REBCO strands since it is tape-shaped and difficult to twist. Therefore, we propose a distributed armature winding which combines two types of racetrack double pancakes. Each double pancake comprises two-strand insulated REBCO superconducting parallel conductors transposed inside the pancake for current equalization. In this study, we perform an experimental demonstration of the current equalization based on the transposition of the distributed armature winding. We made coils with two-strand as a simplified, but the actual coils were needed more 10 strand parallel conductors. In future works, we will manufacture transposed parallel conductor coils using much more strands and measure the current distribution. Additionally, this study measured the current distribution with only the stater. Thus, we will combine the rotor and measure the magnetic field distribution of the rotating magnetic field in the armature.

DOI： 10.1109/TASC.2023.3241822

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：IEEE Transactions on Applied Superconductivity  

To realize a large current capacity in REBa2Cu3Oy superconducting coils, we have proposed a cabling design for the transposed multi-strand parallel conductors. This cabling design is also useful for a superconducting armature coil in a fully superconducting rotating machine system. Very recently, we developed an analytical method based on simple modeling, to roughly calculate the current distributions among the continuous strands in rotating machine conditions. In this manuscript, the current distributions predicted by the analytical method were compared with the measured values. Further, to understand the complex current distribution property for the three-strand parallel conductors, the turn number dependence of the current distribution with various transposition combinations was investigated. The current branches were measured under liquid nitrogen temperature of 77.3 K by Rogowski coils by applying AC transport current. The analytical method described the complex current distribution of the strands well, especially the coil with a large number of turns.

DOI： 10.1109/TASC.2023.3241824

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Superconductor Science and Technology  

Fully superconducting rotating machines employing REBa<inf>2</inf>Cu<inf>3</inf>O <inf>y</inf> (REBCO, RE = rare earth elements or Y) superconducting armature and field coils, are particularly interesting for aircraft applications, owing to their high output power density (kW kg⁻¹). To achieve high current capability in superconducting coils, we have proposed a cabling design for transposed multi-strand parallel conductors. In the parallel conductor design, the REBCO strands are insulated from each other, except for both terminal ends, and transposed during the winding process to achieve uniform current distribution by cancellation of interlinkage magnetic flux between the strands. In this study, a simplified analytical method considering inductances was developed based on Laplace’s equation in cylindrical coordinates to roughly calculate the current distributions of multi-strands under armature coil conditions. The validity of the analytical method was investigated through current distribution measurements of the sample coils wound with two-strand parallel conductors. Consequently, the analytical method was validated with approximately 10% deviation under the experimental coil conditions. To establish a more accurate analysis method, certain improvements are needed.

DOI： 10.1088/1361-6668/acca4f

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：IEEE Transactions on Applied Superconductivity  

We investigated current distribution in three-strand transposed parallel conductors consisting of REBa2Cu3Oy (REBCO, RE = rare earth) superconducting tapes under applied AC magnetic fields. We recently derived the theoretical expression for the additional AC loss caused by the formation of three-strand transposed parallel conductors and proved its validity through experiments. However, the conditions of each strand and current distribution have not yet been discussed. Accordingly, we measured the current distribution and compared it with the calculated distribution derived using the theoretical expression. From the results, we found that the current branch ratio of the three-strand can also be predicted via the theoretical expression.

DOI： 10.1109/TASC.2022.3154338

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：IEEE Transactions on Applied Superconductivity  

A large AC loss is generated in armature windings composed of a REBa2Cu3Oy (REBCO, RE = rare earth, Eu, Gd, etc.) wire in a fully superconducting synchronous generator. In aircraft applications, liquid nitrogen is suitable for cooling windings because of its specific heat capacity and dielectric strength. The evaporation of liquid refrigerant significantly decreases the dielectric strength, which results in an increase in the risk of accidents by discharging. For safe operation, the temperature in the generator is set below the boiling point of nitrogen (∼77 K). We calculated the temperature rise caused by the AC loss and others by applying a method that estimates the AC loss from the experimental results. This paper addresses the electromagnetic-thermal analysis in finite element method to calculate the temperature rise and proves the feasibility of a fully superconducting generator cooled by liquid nitrogen, that is, the temperature is maintained below 77 K. The output power is 10 MW. The temperature of liquid nitrogen was assumed to be 65 K, and its flow speed was set as a parameter. Additionally, we confirmed that designing a method that determines the number of parallel conductors of REBCO windings considering the temperature rise can enhance the output power density.

DOI： 10.1109/TASC.2022.3160660

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：IEEE Transactions on Applied Superconductivity  

For extensive use in electric vehicles, electric airplanes, and other such applications, superconducting motors are designed to be lightweight and have a high power density. Rare-earth barium copper oxide (REBCO) tapes are considered a potential material for use in these motors because of their high critical current density. Because REBCO can be modeled into tape shapes, motors with racetrack coils as armature windings have been studied. However, racetrack coils are inferior in terms of increasing the interlinkage flux to the rotor compared with distributed windings. In this study, we propose trapezoidal REBCO tape coils for shaping armature windings into distributed windings. Next, 2 kW-class induction motors using two types of coils - the trapezoidal and racetrack coils - were designed to compare the characteristics of the two motors. The JMAG-Designer software was used to perform electromagnetic simulations on the two models. The results revealed that the motor with trapezoidal coils required less REBCO tapes and exhibited a lower vertical component of magnetic flux density than the racetrack coils did. Therefore, the AC loss of the trapezoidal coils becomes lower than that of the racetrack coils, and the trapezoidal coils weigh less than racetrack coils.

DOI： 10.1109/TASC.2022.3160146

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記述言語：英語   掲載種別：研究論文（その他学術会議資料等）   出版者・発行元：Journal of Physics Conference Series  

Generators used in electric aircraft require a high-power density, and AC loss is also a significant problem. We designed 10 MW REBCO superconducting synchronous generators at 64 K to achieve a power density of 20 kW/kg and low AC loss. In this study, electromagnetic analyses were performed using finite element method software. Consequently, the thickness of the back yoke is 50 mm or less so that the generator can meet the target power density. The method of decreasing the magnetic field of the armature winding and increasing that of the field winding was used to effectively reduce the AC loss. As a result, the generator achieved a high-power density of 21.0 kW/kg, reducing the AC loss from over 600 kW to 415 kW.

DOI： 10.1088/1742-6596/2323/1/012037

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1109/tasc.2021.3055452

担当区分：筆頭著者   記述言語：その他   掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/j.physc.2020.1353801

担当区分：筆頭著者   記述言語：日本語  

記述言語：その他   掲載種別：研究論文（学術雑誌）  

DOI： 10.1109/tasc.2020.2989746

担当区分：筆頭著者   記述言語：その他   掲載種別：研究論文（その他学術会議資料等）  

<title>Abstract</title>
In this study, we focused on the dependence of the AC loss in REBa₂Cu₃O#D
<italic>y</italic>
#DR (REBCO, RE = rare earth, Y, Eu, Gd) superconducting tapes stacked perpendicular to the tape face on the interval between the superconducting layers. The AC loss of the 2-layer stacked tapes with various interval in perpendicular field was investigated by pickup-coil method. The AC loss for external applied magnetic field, <italic>B</italic>
_m, below the penetration field, <italic>B</italic>
_p, increases with increasing the interval. In the case that the ratio of the distance between the neighboring superconducting layer, <italic>D</italic>, to the width of the tape, <italic>w</italic>, (<italic>D</italic>/<italic>w</italic>) is smaller than 0.1, the AC loss of 2-layer tapes decreased to 1/2 of that of 1-layer tape. On the other hand, in the case of <italic>D</italic>/<italic>w</italic> being larger than 0.1, the AC loss of 2-layer tapes was larger than 1/2 and it approached the AC loss of 1-layer tape with increasing <italic>D</italic>/<italic>w</italic>. From the result obtained in this study, it is predicted that, for <italic>B</italic>
_m below <italic>B</italic>
_p, the AC loss of stacked REBCO tapes with large <italic>D</italic>/<italic>w</italic>, such as multifilamentary tapes, is larger than the AC loss of stacked non-scribed REBCO tapes. However, for <italic>B</italic>
_m above <italic>B</italic>
_p: a large AC loss region, it is known that the AC loss of the multifilamentary tapes decreases compared with that of non-scribed tapes. Next step, AC loss of the multifilamentary tapes for <italic>B</italic>
_m below <italic>B</italic>
_p will be investigated experimentally and theoretically.

DOI： 10.1088/1742-6596/1293/1/012037

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1109/tasc.2019.2906655

記述言語：英語   掲載種別：研究論文（その他学術会議資料等）  

DOI： 10.1088/1742-6596/1054/1/012037

開催年月日： 2025年12月

記述言語：英語   会議種別：ポスター発表  

国名：日本国  

開催年月日： 2025年10月 - 2025年11月

記述言語：日本語   会議種別：口頭発表（招待・特別）  

国名：日本国  

開催年月日： 2025年9月

記述言語：英語   会議種別：ポスター発表  

開催地：Porto, Portugal   国名：ポルトガル共和国  

開催年月日： 2025年9月

記述言語：英語   会議種別：ポスター発表  

開催地：Porto, Portugal   国名：ポルトガル共和国  

開催年月日： 2025年9月

記述言語：英語   会議種別：ポスター発表  

開催地：Porto, Portugal   国名：ポルトガル共和国  

開催年月日： 2025年9月

記述言語：英語   会議種別：ポスター発表  

開催地：Porto, Portugal   国名：ポルトガル共和国  

開催年月日： 2025年9月

記述言語：英語   会議種別：口頭発表（一般）  

開催地：Porto, Portugal   国名：ポルトガル共和国  

開催年月日： 2025年9月

記述言語：英語   会議種別：ポスター発表  

開催地：Porto, Portugal   国名：ポルトガル共和国  

開催年月日： 2025年9月

記述言語：日本語  

開催地：福岡工業大学   国名：日本国  

開催年月日： 2025年9月

記述言語：日本語  

開催地：福岡工業大学   国名：日本国  

開催年月日： 2025年9月

記述言語：日本語  

開催地：福岡工業大学   国名：日本国  

開催年月日： 2025年7月

記述言語：英語  

国名：アメリカ合衆国  

開催年月日： 2025年7月

記述言語：英語  

国名：アメリカ合衆国  

開催年月日： 2025年5月

記述言語：日本語   会議種別：口頭発表（一般）  

国名：日本国  

開催年月日： 2025年3月

記述言語：日本語  

国名：日本国  

開催年月日： 2025年3月

記述言語：英語   会議種別：口頭発表（基調）  

開催地：Lübeck, Germany  

開催年月日： 2024年12月

記述言語：英語   会議種別：ポスター発表  

国名：日本国  

開催年月日： 2024年11月

記述言語：日本語   会議種別：ポスター発表  

国名：日本国  

開催年月日： 2024年11月

記述言語：日本語   会議種別：ポスター発表  

国名：日本国  

開催年月日： 2024年9月

記述言語：日本語  

開催地：鹿児島大学   国名：日本国  

開催年月日： 2024年9月

記述言語：日本語  

開催地：鹿児島大学   国名：日本国  

開催年月日： 2024年9月

記述言語：日本語  

開催地：鹿児島大学   国名：日本国  

開催年月日： 2024年9月

記述言語：日本語  

開催地：鹿児島大学   国名：日本国  

開催年月日： 2024年9月

記述言語：日本語  

開催地：鹿児島大学   国名：日本国  

開催年月日： 2024年9月

記述言語：日本語  

開催地：鹿児島大学   国名：日本国  

開催年月日： 2024年9月

記述言語：日本語  

開催地：鹿児島大学   国名：日本国  

開催年月日： 2024年9月

記述言語：英語   会議種別：ポスター発表  

開催地：ソルトレイクシティ   国名：アメリカ合衆国  

開催年月日： 2024年9月

記述言語：英語   会議種別：ポスター発表  

開催地：ソルトレイクシティ   国名：アメリカ合衆国  

開催年月日： 2024年9月

記述言語：英語   会議種別：ポスター発表  

開催地：ソルトレイクシティ   国名：アメリカ合衆国  

開催年月日： 2024年9月

記述言語：英語   会議種別：ポスター発表  

開催地：ソルトレイクシティ   国名：アメリカ合衆国  

開催年月日： 2024年9月

記述言語：英語   会議種別：ポスター発表  

開催地：ソルトレイクシティ   国名：アメリカ合衆国  

開催年月日： 2024年3月

記述言語：日本語  

国名：日本国  

開催年月日： 2024年3月

記述言語：日本語  

国名：日本国  

開催年月日： 2024年3月

記述言語：日本語  

国名：日本国  

開催年月日： 2024年3月

記述言語：日本語  

国名：日本国  

開催年月日： 2023年12月

記述言語：日本語  

国名：日本国  

開催年月日： 2023年11月

記述言語：英語  

国名：ニュージーランド  

開催年月日： 2023年11月

記述言語：英語  

国名：ニュージーランド  

開催年月日： 2023年11月

記述言語：英語  

国名：ニュージーランド  

開催年月日： 2023年11月

記述言語：英語  

国名：ニュージーランド  

開催年月日： 2023年9月

記述言語：英語  

国名：フランス共和国  

開催年月日： 2023年9月

記述言語：英語  

国名：フランス共和国  

開催年月日： 2023年9月

記述言語：英語  

国名：フランス共和国  

開催年月日： 2023年9月

記述言語：英語  

国名：フランス共和国  

開催年月日： 2023年9月

記述言語：日本語  

開催地：崇城大学   国名：日本国  

開催年月日： 2023年9月

記述言語：日本語  

開催地：崇城大学   国名：日本国  

開催年月日： 2023年9月

記述言語：日本語  

開催地：崇城大学   国名：日本国  

開催年月日： 2023年9月

記述言語：日本語  

開催地：崇城大学   国名：日本国  

開催年月日： 2023年9月

記述言語：日本語  

開催地：崇城大学   国名：日本国  

開催年月日： 2023年9月

記述言語：日本語  

開催地：崇城大学   国名：日本国  

開催年月日： 2023年9月

記述言語：日本語  

開催地：崇城大学   国名：日本国  

開催年月日： 2023年9月

記述言語：日本語  

開催地：崇城大学   国名：日本国  

開催年月日： 2023年5月 - 2023年6月

記述言語：日本語  

国名：その他  

開催年月日： 2023年5月 - 2023年6月

記述言語：日本語  

国名：その他  

開催年月日： 2022年12月

記述言語：日本語  

国名：日本国  

開催年月日： 2022年12月

記述言語：日本語  

国名：日本国  

開催年月日： 2022年10月

記述言語：英語  

国名：アメリカ合衆国  

開催年月日： 2022年10月

記述言語：英語  

国名：アメリカ合衆国  

開催年月日： 2022年10月

記述言語：英語  

国名：アメリカ合衆国  

開催年月日： 2022年10月

記述言語：英語  

国名：アメリカ合衆国  

開催年月日： 2022年10月

記述言語：英語  

国名：アメリカ合衆国  

開催年月日： 2022年10月

記述言語：英語  

国名：アメリカ合衆国  

開催年月日： 2022年3月

記述言語：日本語  

国名：その他  

開催年月日： 2021年11月 - 2021年12月

記述言語：英語  

国名：その他  

開催年月日： 2021年11月

記述言語：英語  

国名：その他  

開催年月日： 2021年11月

記述言語：英語  

国名：その他  

開催年月日： 2021年11月

記述言語：英語  

国名：その他  

開催年月日： 2021年11月

記述言語：英語  

国名：その他  

開催年月日： 2021年11月

記述言語：英語  

国名：その他  

開催年月日： 2021年9月

記述言語：日本語  

国名：その他  

開催年月日： 2020年10月

記述言語：日本語  

国名：その他  

開催年月日： 2020年10月 - 2020年11月

記述言語：英語  

国名：その他  

開催年月日： 2019年10月

記述言語：日本語  

国名：その他  

開催年月日： 2019年9月

記述言語：日本語  

国名：その他  

開催年月日： 2019年9月

記述言語：英語  

国名：その他  

開催年月日： 2019年9月

記述言語：英語  

国名：その他  

開催年月日： 2019年9月

記述言語：英語  

国名：その他  

開催年月日： 2019年9月

記述言語：英語  

国名：その他  

開催年月日： 2019年5月

記述言語：日本語  

国名：その他  

開催年月日： 2018年12月

記述言語：英語  

国名：その他  

開催年月日： 2018年11月

記述言語：日本語  

国名：その他  

開催年月日： 2018年10月 - 2018年11月

記述言語：英語  

国名：その他  

開催年月日： 2018年3月

記述言語：日本語  

国名：その他  

開催年月日： 2017年12月

記述言語：英語  

国名：その他  

開催年月日： 2017年11月

記述言語：日本語  

国名：その他  

開催年月日： 2017年9月

記述言語：日本語  

国名：その他  

種別：査読等 

外国語雑誌　査読論文数：1

【九州大学、次世代電動航空機向け400kW級全超電導モータの回転試験に世界初成功】https://www.drone.jp/news/2023060915420467765.html

【空飛ぶクルマへの適用目指す　九大が次世代航空機向けモータの回転試験に世界初成功】https://www.zakzak.co.jp/article/20230611-S3CARWTCAVPFTI7GHA2QTOQT6E/

【九州大学など　次世代電動航空機向け全超電導モーター　回転試験に世界初成功】

【次世代電動航空機向け 400kW 級全超電導モータの回転試験に世界で初めて成功】