Research Output 1983 2020

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1983
2 Citations (Scopus)

Megahertz dc-to-dc converters controlled by an amorphous core

Harada, K., Sakamoto, H., Sasada, I. & Shoyama, M., Sep 1983, In : IEEE Transactions on Magnetics. 19, 5, p. 2082-2084 3 p.

Research output: Contribution to journalArticle

Multivibrators
Networks (circuits)
Bipolar transistors
Transistors
Feedback
1984
1 Citation (Scopus)

A practical in situ wire: a composite wire with many in situ processed Nb3Sn cores of an internal diffusion type

Yamafuji, K., Sumiyoshi, F., Akenaga, Y., Iwakuma, M., Onodera, R. & Mori, N., Apr 1984, In : Cryogenics. 24, 4, p. 191-199 9 p.

Research output: Contribution to journalArticle

Cable cores
wire
Wire
composite materials
Composite materials
7 Citations (Scopus)

Steady-State Characteristics of the Push-Pull DC-to-DC Converter

Shoyama, M. & Harada, K., 1984, In : IEEE Transactions on Aerospace and Electronic Systems. AES-20, 1, p. 50-56 7 p.

Research output: Contribution to journalArticle

Inductance
Electric potential
1985

On the turn-off of GTO by a small saturable core

Harada, K., Sakamoto, H. & Shoyama, M., Jan 1 1985, In : IEEJ Transactions on Electronics, Information and Systems. 105, 11, p. 219-226 8 p.

Research output: Contribution to journalArticle

1986
38 Citations (Scopus)

Anomalous magnetic behavior due to reversible fluxoid motion in superconducting multifilamentary wires with very fine filaments

Sumiyoshi, F., Matsuyama, M., Noda, M., Matsushita, T., Funaki, K., Iwakuma, M. & Yamafuji, K., Feb 1986, In : Japanese Journal of Applied Physics. 25, 2 A, p. L148-L150

Research output: Contribution to journalArticle

Superconducting wire
Hysteresis
filaments
wire
critical current

Dynamic characteristics of the push‐pull dc‐dc converter

Shoyama, M. & Harada, K., Jan 1 1986, In : Electronics and Communications in Japan (Part II: Electronics). 69, 5, p. 100-109 10 p.

Research output: Contribution to journalArticle

Electric instrument transformers
dynamic characteristics
converters
transformers
Transfer functions
3 Citations (Scopus)

Dynamic Characterstics of the Push-Pull DC to DC Converter

Shoyama, M. & Harada, K., Jan 1986, In : IEEE Transactions on Power Electronics. PE-1, 1, p. 3-8 6 p.

Research output: Contribution to journalArticle

8 Citations (Scopus)

Effects of tin-diffusion barriers on hysteresis loss and coupling current loss in bronze-processed Nb3Sn multifilamentary composites

Miyahara, K., Sumiyoshi, F., Funaki, K., Iwakuma, M., Kubota, Y., Ogasawara, T. & Yamafuji, K., Apr 1986, In : Cryogenics. 26, 4, p. 234-241 8 p.

Research output: Contribution to journalArticle

Diffusion barriers
Tin
Bronze
bronzes
Hysteresis
converters
transistors
saturation
Feedback
Switching frequency
10 Citations (Scopus)

On the High-Speed Turn-Off of a Power Transistor By a Small Saturable Core

Harada, K., Sakamoto, H. & Shoyama, M., Jul 1986, In : IEEE Transactions on Power Electronics. PE-1, 3, p. 175-180 6 p.

Research output: Contribution to journalArticle

Switching frequency
Equivalent circuits
Inductance
Deterioration
Capacitance
1987

17 TESLA SUPERCONDUCTING MAGNET WITH MULTIFILAMENTARY SUPERCONDUCTORS.

Takeo, M., Funaki, K., Sato, S., Yamafuji, K., Iwakuma, M., Hiramatsu, M., Matsumoto, K. & Hamada, M., Jan 1 1987, In : IEEE Transactions on Magnetics. MAG-23, 2

Research output: Contribution to journalArticle

Superconducting magnets
Superconducting materials
Magnets
Quenching
Magnetic fields
29 Citations (Scopus)

A superconducting sub-structure in sintered ybacu3o7-x plates

Funaki, K., Iwakuma, M., Sudo, Y., Ni, B., Kisu, T., Matsushita, T., Takeo, M. & Yamafuji, K., Sep 1987, In : Japanese Journal of Applied Physics. 26, 9A, p. 1445-1447 3 p.

Research output: Contribution to journalArticle

Magnetization
magnetization
Magnetic fields
magnetic fields
4 Citations (Scopus)

Development of Nb3Sn superconducting wires for AC use

Yamafuji, K., Iwakuma, M., Tomita, Y. & Funaki, K., Jan 1 1987, In : IEEE Transactions on Magnetics. 23, 2, p. 1355-1358 4 p.

Research output: Contribution to journalArticle

Superconducting wire
Wire
Powder metallurgy
Cables
Availability

DEVELOPMENT OF Nb3Sn SUPERCONDUCTING WIRES FOR AC USE.

Yamafuji, K., Iwakuma, M., Tomita, Y., Funaki, K., Sumiyoshi, F., Fukutsuka, T., Ogawa, R., Miyatake, T. & Matsumoto, K., Jan 1 1987, In : IEEE Transactions on Magnetics. MAG-23, 2

Research output: Contribution to journalArticle

Superconducting wire
Wire
Powder metallurgy
Cables
38 Citations (Scopus)

Estimate of attainable critical current density in superconducting yba2cu3o7-ै

Matsushita, T., Iwakuma, M., Sudo, Y., Ni, B., Kisu, T., Funaki, K., Takeo, M. & Yamafuji, K., Sep 1987, In : Japanese Journal of Applied Physics. 26, 9A, p. 1524-1526 3 p.

Research output: Contribution to journalArticle

Critical current density (superconductivity)
Flux pinning
Oxide superconductors
Electron scattering
Twinning
2 Citations (Scopus)

On the Effective Turn-Off of GTO by a Small Saturable Core

Harada, K., Sakamoto, H. & Shoyama, M., Jan 1 1987, In : IEEE Transactions on Power Electronics. PE-2, 1, p. 20-27 8 p.

Research output: Contribution to journalArticle

Magnetic cores
Inductance
Capacitance
Energy utilization
Networks (circuits)
3 Citations (Scopus)

The Similarity Relationship in Unipolar Ion Flow Fields with Rod-to-Plane Gaps

Hara, M., Kaneko, T., Suehiro, J., Nakamura, Y. & Akazaki, M., Jan 1 1987, In : IEEJ Transactions on Fundamentals and Materials. 107, 5, p. 233-240 8 p.

Research output: Contribution to journalArticle

Flow fields
Ions
1988
48 Citations (Scopus)

Ac inductive measurement of intergrain and intragrain currents in high-tc oxide superconductors

Ni, B., Munakata, T., Matsushita, T., Iwakuma, M., Funaki, K., Takeo, M. & Yamafuji, K., Sep 1988, In : Japanese Journal of Applied Physics. 27, 9 R, p. 1658-1662 5 p.

Research output: Contribution to journalArticle

Oxide superconductors
Current density
current density
oxides
Magnetic flux
23 Citations (Scopus)

Critical transport current density in sintered oxide superconductors with high critical temperature

Matsushita, T., Ni, B., Sudo, Y., Iwakuma, M., Funaki, K., Takeo, M. & Yamafuji, K., Jun 1988, In : Japanese Journal of Applied Physics. 27, 6R, p. 929-936 8 p.

Research output: Contribution to journalArticle

Oxide superconductors
Volume fraction
critical temperature
Current density
current density
45 Citations (Scopus)

Phase-Controlled DC-AC Converter with High-Frequency Switching

Harada, K., Sakamoto, H. & Shoyama, M., Oct 1988, In : IEEE Transactions on Power Electronics. 3, 4, p. 406-411 6 p.

Research output: Contribution to journalArticle

Switching frequency
Switches
Uninterruptible power systems
Electric commutation
Electric power systems
1989
21 Citations (Scopus)

Breakdown Characteristics of Cryogenic Gaseous Nitrogen and Estimation of its Electrical Insulation Properties

Hara, M., Suehiro, J., Matsumoto, H. & Kaneko, T., Aug 1989, In : IEEE Transactions on Electrical Insulation. 24, 4, p. 609-617 9 p.

Research output: Contribution to journalArticle

Cryogenics
Insulation
Liquid nitrogen
Nitrogen
Gases
1 Citation (Scopus)

Increase in coupling-current losses of superconducting cables due to first-stage cabling Part 2: optimum structure of solder-impregnated sub-cable with normal-metal strands

Funaki, K., Ichimaru, O., Iwakuma, M., Sumiyoshi, F., Miyahara, K. & Yamafuji, K., Apr 1989, In : Cryogenics. 29, 4, p. 423-428 6 p.

Research output: Contribution to journalArticle

Superconducting cables
solders
strands
Soldering alloys
cables

Methods for the improvement of electrical insulation in vacuum in the presence of transverse magnetic field

Hara, M., Suehiro, J., Shigematsu, H. & Yano, S., Jan 1 1989, In : IEEJ Transactions on Fundamentals and Materials. 109, 9, p. 375-382 8 p.

Research output: Contribution to journalArticle

Insulation
Vacuum
Magnetic fields
10 Citations (Scopus)

Quench analysis in a 72 kVA superconducting four-winding power transformer

Iwakuma, M., Funaki, K., Kanetaka, H., Tasaki, K., Takeo, M. & Yamafuji, K., Nov 1989, In : Cryogenics. 29, 11, p. 1055-1062 8 p.

Research output: Contribution to journalArticle

Power transformers
transformers
propagation
Superconducting cables
propagation velocity
1990
43 Citations (Scopus)

Abnormal quench process with very fast elongation of normal zone in multi-strand superconducting cables

Iwakuma, M., Kanetaka, H., Tasaki, K., Funaki, K., Takeo, M. & Yamafuji, K., Aug 1990, In : Cryogenics. 30, 8, p. 686-692 7 p.

Research output: Contribution to journalArticle

Superconducting cables
strands
cables
elongation
Elongation
6 Citations (Scopus)

Breakdown characteristics of cryogenic gaseous helium in uniform electric field and space charge modified non-uniform field

Hara, M., Suehiro, J. & Matsumoto, H., Jan 1 1990, In : Cryogenics. 30, 9, p. 787-794 8 p.

Research output: Contribution to journalArticle

Helium
Electric space charge
Cryogenics
coronas
cryogenics
1 Citation (Scopus)

Methods for the improvement of electrical insulation in vacuum in the presence of transverse magnetic field

Hara, M., Suehiro, J., Shigematsu, H. & Yano, S., Jan 1 1990, In : Electrical Engineering in Japan. 110, 2, p. 27-35 9 p.

Research output: Contribution to journalArticle

Insulation
Vacuum
Magnetic fields
1991
17 Citations (Scopus)

Instability in kiloamp class a.c. superconducting cables

Funaki, K., Nakashima, M., Iwakuma, M., Takeo, M. & Yamafuji, K., Jul 1991, In : Cryogenics. 31, 7, p. 594-597 4 p.

Research output: Contribution to journalArticle

Superconducting cables
strands
cables
current distribution
Degradation
1 Citation (Scopus)

Mobilities of charge carriers generated by corona discharge in low temperature helium gas

Suehiro, J., Yamamoto, K. & Hara, M., Aug 14 1991, In : Journal of Physics D: Applied Physics. 24, 8, p. 1360-1366 7 p.

Research output: Contribution to journalArticle

Helium
electric corona
Charge carriers
Discharge (fluid mechanics)
charge carriers
4 Citations (Scopus)

Quench Protection of Superconducting Transformers

Iwakuma, M., Funaki, K., Takeo, M. & Yamafuji, K., Mar 1991, In : IEEE Transactions on Magnetics. 27, 2, p. 2080-2083 4 p.

Research output: Contribution to journalArticle

Electric potential
Inductance
Copper
Electric fault currents
Equivalent circuits
1992
4 Citations (Scopus)

Deflection of Streamer Channels in High Magnetic Field

Hara, M., Suehiro, J. & Wakiyama, T., Jan 1 1992, In : IEEE Transactions on Electrical Insulation. 27, 6, p. 1179-1185 7 p.

Research output: Contribution to journalArticle

Electric space charge
Electric fields
Magnetic fields
Lorentz force
Dielectric films
12 Citations (Scopus)

Development of a Large-Capacity Superconducting Cable for 1000 KV A-Class Power Transformers

Funaki, K., Iwakuma, M., Satoh, S., Hiramatsu, M., Takeo, M., Yamafuji, K., Nonaka, S., Hoshino, M., Simada, M., Yoneda, E. S., Sasaki, T., Fujioka, T., Kumano, T. & Suzuki, E., Jan 1 1992, In : IEEE Transactions on Magnetics. 28, 1, p. 394-397 4 p.

Research output: Contribution to journalArticle

Superconducting cables
Power transformers
Cables
Critical currents
Copper
8 Citations (Scopus)

Losses of Aluminum-Stabilized Superconducting Conductors for Large Helical Device

Sumiyoshi, F., Kanai, Y., Kawashima, T., Iwakuma, M., Mito, T., Takahata, K., Yanagi, N. & Yamamoto, J., Jan 1 1992, In : IEEE Transactions on Magnetics. 28, 1, p. 210-213 4 p.

Research output: Contribution to journalArticle

Aluminum
Superconducting magnets
Skin
Metals
Experiments
16 Citations (Scopus)

Pinning characteristics in multifilamentary NbTi superconducting wires with submicrometre filaments introduced artificial pinning centres

Miura, O., Matsumoto, K., Tanaka, Y., Yamafuji, K., Harada, N., Iwakuma, M., Funaki, K. & Matsushita, T., 1992, In : Cryogenics. 32, 3, p. 315-322 8 p.

Research output: Contribution to journalArticle

Superconducting wire
filaments
wire
Wire
Magnetic fields
1993
9 Citations (Scopus)

Sweep-rate dependences of losses in aluminum-stabilized superconducting conductors for the Large Helical Device

Sumiyoshi, F., Kanai, Y., Kawashima, T., Iwakuma, M., Mito, T., Takahata, K., Yanagi, N. & Yamamoto, J., Jan 1993, In : Fusion Engineering and Design. 20, C, p. 371-376 6 p.

Research output: Contribution to journalArticle

Aluminum
Skin
Metals
Experiments
1 Citation (Scopus)

The development of a 2.5 T/100 kV a AC superconducting magnet using a high-Jc NbTi superconducting wire having Nb artificial pins

Miura, O., Inoue, I., Suzuki, T., Matsumoto, K., Tanaka, Y., Funaki, K., Iwakuma, M., Yamafuji, K. & Matsushita, T., Dec 1 1993, In : Superconductor Science and Technology. 6, 10, p. 748-754 7 p., 008.

Research output: Contribution to journalArticle

Superconducting wire
Superconducting magnets
superconducting magnets
Magnets
alternating current
12 Citations (Scopus)

Theoretical evaluation of longitudinal a.c. losses in large-capacity superconducting cables for 50 60 Hz use

Funaki, K., Ueda, H., Yoshlya, F., Iwakuma, M., Takeo, M. & Yamafuji, K., Jan 1 1993, In : Cryogenics. 33, 2, p. 190-198 9 p.

Research output: Contribution to journalArticle

Superconducting cables
strands
cables
Cables
Hysteresis
10 Citations (Scopus)

Zero-voltage-switching realized by magnetizing current of transformer in push-pull current-fed DC-DC converter

Shoyama, M. & Harada, K., 1993, In : Unknown Journal. p. 178-184 7 p.

Research output: Contribution to journalArticle

Zero voltage switching
DC-DC converters
Electric potential
Networks (circuits)
Electric commutation
1994
36 Citations (Scopus)

Enhanced Jc properties in superconducting NbTi composites by introducing Nb artificial pins with a layered structure

Matsumoto, K., Takewaki, H., Tanaka, Y., Miura, O., Yamafuji, K., Funaki, K., Iwakuma, M. & Matsushita, T., Dec 1 1994, In : Applied Physics Letters. 64, 1, p. 115-117 3 p.

Research output: Contribution to journalArticle

composite materials
ribbons
critical current
current density
cross sections
8 Citations (Scopus)

Frequency dependences of Ac losses in (Bi1-xPbx)2Sr2Ca2Cu3Oy bulk superconductors in Ac magnetic field

Iwakuma, M., Konomi, H., Funaki, K., Takeo, M., Kuroda, K., Tanaka, Y., Mimura, M., Takita, K., Hiue, H. & Yamafuji, K., 1994, In : Cryogenics. 34, SUPPL. 1, p. 793-796 4 p.

Research output: Contribution to journalArticle

Superconducting materials
Magnetic fields
Maxwell equations
Current voltage characteristics
magnetic fields
6 Citations (Scopus)

Pulsed electrical breakdown in liquid helium in the μs range

Suehiro, J., Yamasaki, K., Matsuo, H., Hara, M. & Gerhold, J., Jun 1994, In : IEEE Transactions on Dielectrics and Electrical Insulation. 1, 3, p. 403-406 4 p.

Research output: Contribution to journalArticle

Helium
Liquids
Electric potential
Superconducting devices
Pulse generators
Lipid bilayers
quantitative analysis
lipid
membrane
Electric potential
1995
7 Citations (Scopus)

Development of high-field a.c. superconducting magnet using ultrafine multifilamentary Nb-Ti superconducting wire with designed Nb artificial pins

Miura, O., Inoue, I., Suzuki, T., Matsumoto, K., Tanaka, Y., Funaki, K., Iwakuma, M., Yamafuji, K. & Matsushita, T., 1995, In : Cryogenics. 35, 3, p. 181-188 8 p.

Research output: Contribution to journalArticle

Superconducting wire
high field magnets
Superconducting magnets
superconducting magnets
Magnets
9 Citations (Scopus)

Development of high Jc Nb-Ti multifilamentary superconducting wires for a.c. use by artificially introduced pins

Miura, O., lnoue, I., Suzuki, T., Matsumoto, K., Tanaka, Y., Funaki, K., Iwakuma, M., Yamafuji, K. & Matsushita, T., 1995, In : Cryogenics. 35, 3, p. 169-180 12 p.

Research output: Contribution to journalArticle

Superconducting wire
filaments
wire
Magnetic fields
Flux pinning
3 Citations (Scopus)

Experimental Evaluation of AC Losses in Superconducting Multifilamentary Wires for 50/60 Hz Use Exposed to a Magnetic Field with Arbitrary Angle with the Wire Axis

Kanetaka, H., Ueda, H., Eguchi, Y., Iwakuma, M., Funaki, K., Takeo, M., Yamafuji, K., Kumano, T., Ichihara, M. & Miyake, S., Jun 1995, In : IEEE Transactions on Applied Superconductivity. 5, 2, p. 737-740 4 p.

Research output: Contribution to journalArticle

Superconducting wire
alternating current
wire
Wire
Magnetic fields
2 Citations (Scopus)

Experimental evaluation of longitudinal field loss in multiply-twisted superconducting cables for a.c. use

Kanetaka, H., Ueda, H., Eguchi, Y., Iwakuma, M., Funaki, K., Takeo, M., Yamafuji, K., Miyake, S., Kumano, T. & Ichihara, M., May 1995, In : Cryogenics. 35, 5, p. 327-333 7 p.

Research output: Contribution to journalArticle

Superconducting cables
cables
strands
evaluation
Magnetic fields
2 Citations (Scopus)

Simulation test and theoretical analysis of surge propagation in superconducting magnet

Choi, B. J., Ohtsuka, S., Suehiro, J. & Hara, M., Aug 1995, In : Cryogenics. 35, 8, p. 505-513 9 p.

Research output: Contribution to journalArticle

Superconducting magnets
superconducting magnets
propagation
Networks (circuits)
arc discharges
1996

A family of single-switch ZVS-CV DC-to-DC converters

Mizoguchi, T., Ninomiya, T., Ohgai, T. & Shoyama, M., Jan 1 1996, In : IEICE Transactions on Communications. E79-B, 6, p. 849-855 7 p.

Research output: Contribution to journalArticle

Zero voltage switching
Pulse width modulation
Switches
Electric commutation
Electric potential
2 Citations (Scopus)
Electrolytic capacitors
ripples
capacitors
Capacitors
Networks (circuits)
20 Citations (Scopus)

Size effect and statistical characteristics of DC and pulsed breakdown of liquid helium

Suehiro, J., Ohno, K., Takahashi, T., Miyama, M. & Hara, M., Dec 1 1996, In : IEEE Transactions on Dielectrics and Electrical Insulation. 3, 4, p. 507-514 8 p.

Research output: Contribution to journalArticle

Helium
Weibull distribution
Electric fields
Electrodes
Distribution functions