-
H. Tsuji,
K. Okuno,
R. Thome,
E. Salpietro,
S. Egorov,
N. Martovetsky,
M. Ricci,
R. Zanino,
G. Zahn,
A. Martinez, [......],
R. Vieira,
P. Michael,
M. Takayasu,
G. Bevilacqua,
R.K. Maix,
R. Manahan,
R.J. Jayakumar,
L. Savoldi,
W. Herz,
A. Ninomiya
[show abstract]
[hide abstract]
ABSTRACT: The world's largest pulsed superconducting coil was successfully tested by charging up to 13 T and 46 kA with a stored energy of 640 MJ. The ITER central solenoid (CS) model coil and CS insert coil were developed and fabricated through an international collaboration, and their cooldown and charging tests were successfully carried out by international test and operation teams. In pulsed charging tests, where the original goal was 0.4 T/s up to 13 T, the CS model coil and the CS insert coil achieved ramp rates to 13 T of 0.6 T/s and 1.2 T/s, respectively. In addition, the CS insert coil was charged and discharged 10 003 times in the 13 T background field of the CS model coil and no degradation of the operational temperature margin directly coming from this cyclic operation was observed. These test results fulfilled all the goals of CS model coil development by confirming the validity of the engineering design and demonstrating that the ITER coils can now be constructed with confidence.
Nuclear Fusion 05/2002; 41(5):645. · 4.09 Impact Factor
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S. Shimamoto,
K. Hamada,
T. Kato,
H. Nakajima,
T. Isono,
T. Hiyama,
M. Oshikiri,
K. Kawano,
M. Sugimoto,
N. Koizumi, [......],
Y. Takahashi,
S. Sekiguchi,
T. Ohuchi,
F. Tajiri,
J. Okayama,
Y. Takaya,
T. Kawasaki,
K. Imahashi,
K. Ohtsu,
H. Tsuji
[show abstract]
[hide abstract]
ABSTRACT: Japan Atomic Energy Research Institute is constructing the
International Thermonuclear Experimental Reactor common test facility
for the Central Solenoid Model Coil which is around 180 tons, a
forced-flow cooled magnet with the maximum pulsed operation of 2 T/s and
generates the rated magnetic field of 13 T at 48 kA with stored energy
of 668 MJ. The test facility consists of a coil vacuum chamber, a
cryogenic system with the 5-kW refrigerator and 500-g/s cryogenic pump,
two pairs of 50-kA current leads, two DC power supplies (50 kA and 60
kA) and two JT-60 pulsed power supplies (50 kA, ±4.5 kV and
±40 kA, ±1.5 kV). The facility will be demonstrating the
refrigeration and operation of a fusion pulsed magnet and the design and
construction will accumulate experience towards the construction of ITER
IEEE Transactions on Magnetics 08/1996; · 1.36 Impact Factor
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T. Isono,
K. Yoshida,
Y. Takahashi,
M. Nishi,
M. Sugimoto,
N. Koizumi,
H. Nakajima,
K. Hamada,
K. Kawano,
T. Kato, [......],
U. Wadayama,
H. Hosono,
T. Sasaki,
A. Miyake,
H. Ebisu,
S. Iwamoto,
K. Okuno,
T. Ando,
H. Tsuji,
R.J. Nelson
[show abstract]
[hide abstract]
ABSTRACT: Japan Atomic Energy Research Institute (JAERI) has been developing
13-T, 40-kA conductors for the ITER Central Solenoid Scalable Model
Coil. The conductors are composed of high performance
(NbTi)<sub>3</sub>Sn strands and titanium conduit. In this development
work, 15-km length strand fabrication from a 100-kg billet, chrome
plating, cabling of 675 or 768 strands, jacketing of titanium conduit,
and so an were conducted by two mass production lines. In this paper,
several test results are reported such as critical current measurements
of full-scale conductors and AC loss measurements of sub-scale
conductors
IEEE Transactions on Magnetics 08/1994; · 1.36 Impact Factor
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Y. Takahashi,
M. Sugimoto,
T. Isono,
H. Nakajima,
T. Ando,
M. Oshikiri,
F. Hosono,
Y. Wadayama,
T. Sasaki, H. Hanawa,
S. Seki,
H. Wakabayashi,
T. Hiyama,
H. Tsuji,
Y. Yamada,
K. Takahashi,
M. Nagata
[show abstract]
[hide abstract]
ABSTRACT: A 40-kA Nb<sub>3</sub>Al cable-in-conduit conductor has been
developed for the toroidal field coils of fusion reactors, because Nb
<sub>3</sub>Al has excellent mechanical performance. This conductor
consists of 405 copper-stabilized multifilamentary strands inserted into
a CuNi circular conduit. The Nb<sub>3</sub>Al strands are fabricated by
the Jelly-roll process with a diameter of 1.22 mm. This conductor could
be operated up to a current of 46 kA at an external field of 11.2 T.
Accordingly, Nb<sub>3</sub>Al promises to soon become a useful
superconductor for large-scale high-field applications, such as fusion
machines
IEEE Transactions on Magnetics 08/1994; · 1.36 Impact Factor
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H. Nakajima,
T. Sasaki,
T. Ando,
M. Nishi,
M. Oshikiri,
T. Hiyama,
Y. Takahashi,
K. Yoshida,
K. Okuno,
T. Kato, [......],
J. Okayama,
K. Imahashi,
K. Outsu,
Y. Takaya,
T. Kawasaki,
Y. Kon,
H. Tsuji,
M. Takayasu,
B. Turck,
F. Wuchner
[show abstract]
[hide abstract]
ABSTRACT: The effect of cyclic pulsed operation on the coil performance was
studied from the electrical and mechanical points of view in the second
experiment of the Nb<sub>3</sub>Sn Demo Poloidal Coil (DPC-EX). Current
sharing temperatures, ac losses, displacements, and strains were
measured before and after cyclic pulsed operation, which consisted of
about 350 cycles. No degradation of the electrical and mechanical
performance of the DPC-EX was observed in the range of these
cycles
IEEE Transactions on Magnetics 08/1994; · 1.36 Impact Factor
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M. Nishi,
H. Nakajima,
T. Ando,
T. Hiyama,
Y. Takahashi,
K. Okuno,
K. Yoshida,
T. Kato,
K. Kawano,
T. Isono, [......],
F. Tajiri,
H. Tsukamoto, H. Hanawa,
F. Hosono,
A. Miyake,
Y. Yasukawa,
K. Yamamoto,
H. Wakabayashi,
Y. Wadayama,
H. Tsuji
[show abstract]
[hide abstract]
ABSTRACT: As a high-field pulse-poloidal test coil in the development
program of superconducting coils for fusion machines, a 1 m-inner
diameter superconducting coil named DPC-EX wound with 10 kA Nb<sub>3
</sub>Sn cable-in-conduit forced-cooled conductor was fabricated and its
various performances were investigated. In its second test, the
ramp-rate limitation phenomenon, i.e. the dependence of the coil current
at quench on the current ramp speed, was studied in detail and a lot of
important data for the design of large pulse coils were achieved
Fusion Engineering, 1993., 15th IEEE/NPSS Symposium on; 11/1993
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T. Isono,
F. Hosono,
N. Koizumi,
M. Sugimoto, H. Hanawa,
Y. Wadayama,
H. Tsukamoto,
T. Sasaki,
M. Nishi,
K. Yoshida,
T. Ando,
H. Tsuji
[show abstract]
[hide abstract]
ABSTRACT: As the first step in development of the center solenoid (CS)
scalable model coil for the International The monuclear Experimental
Reactor (ITER), development of a (NbTi)<sub>3</sub>Sn strand with
characteristics of high current density and low AC loss was started by
the Japan Atomic Energy Research Institute (JAERI). One of the targets
of strand development was set at the point where current density ( J
<sub>c</sub>) was more than 800 A/mm<sup>2</sup> at 12 T and
effective filament diameter ( d <sub>eff</sub>) was less than 10
μm. The other target decided by JAERI was the point of more than 600
A/mm<sup>2</sup> for J <sub>c</sub> and less than 3-μm d
<sub>eff</sub>, because it is possible to design the coil by using
this strand performance. The 0.92-mm-diameter (NbTi)<sub>3</sub>Sn
strands were fabricated by a bronze process, a Nb tube process, and an
internal tin diffusion method to attain one of two targets. Strand
performance of about 800-A/mm<sup>2</sup> J <sub>c</sub> at 12 T
and about 5-μm d <sub>eff</sub> was obtained. The results
from critical current measurements and effective filament diameter
measurements are presented
IEEE Transactions on Appiled Superconductivity 04/1993; · 1.04 Impact Factor
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F. Hosono,
M. Sugimoto,
H. Tsukamoto,
M. Oshikiri, H. Hanawa,
S. Seki,
T. Sasaki,
N. Koizumi,
T. Isono,
Y. Takahashi,
K. Okuno,
M. Nishi,
H. Nakajima,
T. Kato,
K. Yoshida,
T. Ando,
H. Tsuji
[show abstract]
[hide abstract]
ABSTRACT: The conductors of the toroidal field (TF) coil are being developed
for the tokamak fusion reactor ITER International Thermonuclear
Experimental Reactor. While the TF coil will be operated in the DC mode,
the reduction of AC losses is important from the viewpoint of the plasma
disruption. The Toroidal Model Pancake (TMP) is a test coil for
investigating the applicability of a hollow conductor for the TF coil.
The TMP has a 90-m-long hollow conductor, and AC loss measurements were
carried out. This pancake has an inner diameter of 1 m and an outer
diameter of 1.5 m. The results show that the effective diameter of
(NbTi)<sub>3</sub>Sn and NbTi corresponds to the nominal filament
diameter of 4 μm and 39 μm, respectively, and that the coupling
losses depended on the direction of the applied magnetic field. The time
constant of the coupling current was 1.6 s when a magnetic field was
applied in the perpendicular direction
IEEE Transactions on Appiled Superconductivity 04/1993; · 1.04 Impact Factor
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M. Ono,
Y. Wachi,
M. Shimada,
Y. Sanada,
H. Mukai,
T. Hamajima,
T. Fujioka,
M. Nishi,
H. Tsuji,
T. Ando, [......],
M. Oshikiri, H. Hanawa,
H. Ohuchi,
F. Tajiri,
M. Seki,
T. Ohuchi,
J. Okayama,
Y. Takaya,
Y. Kon,
S. Shimamoto
[show abstract]
[hide abstract]
ABSTRACT: The authors describe the electromagnetic results and the quench
phenomena of the DPC-TJ large cable-in-conduit Nb<sub>3</sub>Sn coil
experiment which took place in the summer of 1991. The DPC-TJ coil was
developed by Toshiba and JAERI in collaboration to demonstrate the
realization of (NbTi)<sub>3</sub>Sn superconducting coils for fusion
with high average current density of 40 A/mm<sup>2</sup>. The coil was
charged up to its rated current of 24 kA (40 A/mm<sup>2</sup>) at 7.6 T
without quench in the DPC test facility. Thereafter, the electromagnetic
performance was tested by measuring I <sub>c</sub> and
T <sub>cs</sub>, and the critical current at 12 T was estimated
to be 41 kA. The quench phenomena of the DPC-TJ coil were also tested by
measuring normal-zone propagation velocity to get the protection design.
In these experiments, very slow and very fast propagation were observed.
Many other electromagnetic results were also obtained, which are
necessary for the design of fusion machines such as International
Thermonuclear Experimental Reactor
IEEE Transactions on Appiled Superconductivity 04/1993; · 1.04 Impact Factor
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M. Sugimoto,
F. Hosono,
T. Isono,
N. Koizumi,
K. Yoshida,
T. Ando,
Y. Takahashi,
M. Nishi,
K. Okuno,
H. Nakajima, [......],
K. Yamamoto,
Y. Yasukawa, H. Hanawa,
M. Oshikiri,
S. Seki,
F. Tajiri,
M. Seki,
T. Ouchi,
J. Okayama,
H. Tsuji
[show abstract]
[hide abstract]
ABSTRACT: Development of a hollow cooling monolithic (TMC-FF) conductor has
been carried out by Japan Atomic Energy Research Institute (JAERI) since
1988. Manufacture of the toroidal model pancake (TMP) made of the TMC-FF
conductor was completed in August, 1991, after trial manufacturing and
verification tests. Experiments on the TMP started in January, 1992, in
the Demo Poloidal Coil (DPC) test facility. Results of cooldown,
pressure drop, stability, and mechanical performance of the TMP are
presented
IEEE Transactions on Appiled Superconductivity 04/1993; · 1.04 Impact Factor
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T.A. Painter,
M.M. Steeves,
M. Takayasu,
C. Gung,
M.O. Hoenig,
H. Tsuji,
T. Ando,
T. Hiyama,
Y. Takahashi,
M. Nishi, [......],
F. Tajiri,
Y. Kon,
H. Shimizu,
Y. Matsuzaki,
S. Oomori,
T. Tani,
K. Oomori,
T. Terakado,
J. Yagyu,
H. Oomori
[show abstract]
[hide abstract]
ABSTRACT: The US Demonstration Poloidal Field Coil (US-DPC) experiment took place successfully at the Japan Atomic Energy Research Institute (JAERI) in late 1990. The 8 MJ niobium-tin coil was leak tight; it performed very well in DC tests; it performed well in AC tests, achieving approximately 70% of its design goal. An unexpected ramp-rate barrier at high currents was identified. The barrier could not be explored in the regime of higher fields and slower ramp rates due to limitations of the background-field coils. This document presents the results of the experiment with as little editing as possible. The coil, conductor, and operating conditions are given. The intent is to present data in a form that can be used by magnet analysts and designers.
12/1991;
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T. Isono,
Y. Takahashi,
K. Yoshida,
K. Okuno,
N. Koizumi,
M. Sugimoto,
M. Nishi,
H. Nakajima,
T. Hiyama,
T. Kato, [......],
T. Hosoya,
N. Watahiki,
T. Ando,
H. Tsuji,
M. Konno,
T. Uede,
I. Itoh,
K. Sakaki,
N. Aoki,
E. Suzuki
[show abstract]
[hide abstract]
ABSTRACT: A description is given of a large scale superconductor test
facility composed of a 13-T magnetic field and a 100-kA sample current.
A superconductor transformer with a 100-kA secondary conductor was
fabricated as a current amplifier in order to supply the 100-kA sample
current. Superconducting split coils with 100-mm clear bore diameter
were fabricated, and a 13-T available field was generated by these
coils. Both the 100-kA superconducting transformer and the 13-T
superconducting split coils were installed in a 2-m-diameter FRP dewar
for the purpose of testing large-scale superconductors. A description is
given of the performance of the 100-kA superconducting transformer and
the 13-T superconducting split coils as well as the results from
critical current measurements of prototype conductors for toroidal coils
IEEE Transactions on Magnetics 04/1991; · 1.36 Impact Factor
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[show abstract]
[hide abstract]
ABSTRACT: The median plane magnetic field of the NSCL superconducting cyclotron magnet (max. field ¿ 6T) has been mapped using an NMR with a D2O probe to measure the field at the center and a search-coil/voltage-to-frequency convertor combination to measure the difference in field between the center and any other point of the magnet. With radial intervals of 2.54 mm and angular intervals of ~ 1°, 360° maps took about 40 min. Radial calibrations were done with a laser interferometer and angular positions were measured with an encoder with 0.001° resolution.
IEEE Transactions on Nuclear Science 11/1985; · 1.45 Impact Factor
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T. Kato,
H. Tsuji,
T. Ando,
Y. Takahashi,
H. Nakajima,
M. Sugimoto,
T. Isono,
N. Koizumi,
K. Kawano,
M. Oshikiri, [......],
H. Takigami,
N. Martovetsky,
P. Michael,
M. Takayasu,
M. Ricci,
R. Zanino,
L. Savoldi,
G. Zahn,
A. Martinez,
R. Maix
[show abstract]
[hide abstract]
ABSTRACT: The largest pulsed superconducting coils ever built, the Central Solenoid (CS) Model Coil and Central Solenoid Insert Coil were successfully developed and tested by international collaboration under the R&D activity of the International Thermonuclear Experimental Reactor (ITER), demonstrating and validating the engineering design criteria of the ITER Central Solenoid coil. The typical achievement is to charge the coil up to the operation current of 46 kA, and the maximum magnetic field to 13 T with a swift rump rate of 0.6 T/s without quench. The typical stored energy of the coil reached during the tests was 640 MJ that is 21 times larger than any other superconducting pulsed coils ever built. The test have shown that the high current cable in conduit conductor technology is indeed applicable to the ITER coils and could accomplish all the requirements of current sharing temperature, AC losses, ramp rate limitation, quench behavior and 10 000-cycle operation.
Fusion Engineering and Design.
-
M. Ono,
H. Mukai,
M. Shimada,
Y. Wachi,
T. Fujioka,
T. Isono,
K. Okuno,
Y. Takahashi,
M. Sugimoto,
H. Hiue, [......],
H. Nakajima,
T. Kato,
M. Oshikiri, H. Hanawa,
F. Tajiri,
T. Ohuchi,
M. Seki,
J. Okayama,
M. Nishi,
H. Tsuji
[show abstract]
[hide abstract]
ABSTRACT: The DPC-TJ coil experiment was successfully carried out at the Japan Atomic Research Institute (JAERI) in 1991. This coil was developed by Toshiba and JAERI in collaboration to demonstrate the realization of superconducting coils for fusion with a high average current density of 40 A mm−2. The DPC-TJ coil was charged up to its rated current of 24 kA (40 A mm−2) at 7.6 T without quench in the DPC test facility. Thereafter electromagnetic performance was tested by measuring Ic and Tcs values, and the critical current at 12 T was estimated at 41 kA. Many electromagnetic results were obtained, which are necessary for the design of future fusion machines such as the International Thermonuclear Experimental Reactor (ITER).
Cryogenics 33(6):586-591. · 0.67 Impact Factor
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N Koizumi,
K Azuma,
Y Tsuchiya,
K Matsui,
Y Takahashi,
H Nakajima,
G. Nishijima,
Y. Nunoya,
T Ando,
T. Isono, [......],
T. Shinba, H Hanawa,
H Tsuji,
K Kikuchi,
A. Fuchs,
P. Bruzzone,
B. Blau,
G. Vesey,
A. Nyilas,
K Okuno
[show abstract]
[hide abstract]
ABSTRACT: A 13 T-46 kA Nb3Al conductor with steel jacket has been developed in the framework of ITER-EDA. The thermal strain will appear on the Nb3Al strands after heat treatment, when the steel jacket is used because of difference in their thermal expansion. The conductor critical current performance is degraded by this process. The critical current performance of this conductor was then studied to verify no degradation during the fabrication and small deterioration in the critical current performance even when the steel jacket is used. The thermal strain is evaluated to be < 0.4% for the developed Nb3Al conductor. The critical current deterioration for this case is < 10%. Also, the critical current of the conductor without the thermal strain shows good agreement with that calculated by the critical current of a strand multiplied by its number, 1152. Consequently, no degradation during the conductor fabrication process can be verified. Moreover, the critical current is expected to be more than 90 kA for the thermal strain of 0.4%, resulting in a large margin against the nominal current, 46 kA. <(c)> 2001 Elsevier Science B.V. All rights reserved.
