-
T. Ogitsu,
Y. Ajima,
M. Anerella,
J. Escallier,
G. Ganetis,
R. Gupta,
D. Hagedorn,
M. Harrison, N. Higashi,
Y. Iwamoto, [......],
T. Obana,
H. Ohhata,
B. Parker,
K. Sasaki,
M. Takasaki,
K. Tanaka,
A. Terashima,
T. Tomaru,
P. Wanderer,
A. Yamamoto
[show abstract]
[hide abstract]
ABSTRACT: The J-PARC Neutrino Experiment, the construction of which starts in JFY 2004, will use a superconducting magnet system for its primary proton beam line. The system, which bends the 50 GeV 0.75 MW proton beam by about 80 degrees, consists of 28 superconducting combined function magnets. The magnets utilize single layer left/right asymmetric coils that generate a dipole field of 2.6 T and a quadrupole field of 18.6 T/m with the operation current of about 7.35 kA. The system also contains a few conduction cooled superconducting corrector magnets that serve as vertical and horizontal steering magnets. All the magnets are designed to provide a physical beam aperture of 130 mm in order to achieve a large beam acceptance. Extensive care is also required to achieve safe operation with the high power proton beam. The paper summarizes the system design as well as some safety analysis results.
IEEE Transactions on Appiled Superconductivity 07/2005; · 1.04 Impact Factor
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T. Nakamoto, N. Higashi,
T. Ogitsu,
A. Terashima,
Y. Ajima,
M. Anerella,
R. Gupta,
Y. Iwamoto,
N. Kimura,
Y. Makida,
T. Obana,
H. Ohhata,
B. Parker,
K. Sasaki,
K. Tanaka,
T. Tomaru,
P. Wanderer,
A. Yamamoto
[show abstract]
[hide abstract]
ABSTRACT: Superconducting combined function magnets will be utilized for the 50 GeV, 750 kW proton beam line for the J-PARC neutrino experiment and an R&D program has been launched at KEK. The magnet is designed to provide a combined function of a dipole field of 2.6 T with a quadrupole field of 19 T/m in a coil aperture of 173.4 mm. Critical magnet components including glass-fiber reinforced phenolic plastic spacers have been successfully developed. The mechanical design has been verified by a 100 mm long short-cut model, and coils have been wound for the first full-length prototype.
IEEE Transactions on Appiled Superconductivity 07/2005; · 1.04 Impact Factor
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T. Nakamoto,
Y. Ajima,
Y. Fujii, N. Higashi,
A. Ichikawa,
N. Kimura,
T. Kobayashi,
Y. Makida,
T. Ogitsu,
H. Ohhata, [......],
M. Harrison,
A. Jain,
J. Muratore,
B. Parker,
P. Wanderer,
T. Obana,
T. Fujii,
E. Hashiguchi,
T. Kanahara,
T. Orikasa
[show abstract]
[hide abstract]
ABSTRACT: Superconducting combined function magnets will be utilized for the 50 GeV, 750 kW proton beam line for the J-PARC neutrino experiment. The magnet is designed to provide a dipole field of 2.6 T combined with a quadrupole field of 19 T/m in a coil aperture of 173.4 mm at a nominal current of 7345 A. Two full-scale prototype magnets to verify the magnet performance were successfully developed. The first prototype experienced no training quench during the excitation test and good field quality was confirmed.
Particle Accelerator Conference, 2005. PAC 2005. Proceedings of the; 06/2005
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T. Ogitsu,
Y. Makida,
T. Kobayashi,
Y. Ajima,
Y. Doi, N. Higashi,
Y. Iwamoto,
A. Ichikawa,
N. Kimura,
T. Nakamoto, [......],
T. Obana,
M. Anerella,
J. Escallier,
R. Gupta,
G. Ganetis,
M. Harrison,
A. Jain,
J. Muratore,
B. Parker,
P. Wanderer
[show abstract]
[hide abstract]
ABSTRACT: A neutrino oscillation experiment using the J-PARC 50 GeV 0.75 MW proton beam is planned as a successor to the K2K project currently being operated at KEK. A superconducting magnet system is required for the arc section of the primary proton beam line to be within the space available at the site. A system with 28 combined function magnets is proposed to simplify the system and optimize the cost. The required fields for the magnets are 2.6 T dipole and 19 T/m quadrupole. The magnets are also required to have a large aperture, 173.4 mm diameter, to accommodate the large beam emittance. The magnets will be protected by cold diodes and cooled by forced flow supercritical helium produced by a 4.5 K, 2∼2.5 kW refrigerator. This paper reports the system overview and the design status.
IEEE Transactions on Appiled Superconductivity 07/2004; · 1.04 Impact Factor
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T. Nakamoto, N. Higashi,
T. Ogitsu,
A. Terashima,
Y. Ajima,
M. Anerella,
R. Gupta,
H. Hattori,
T. Ichihara,
Y. Iwamoto,
N. Kimura,
Y. Makida,
T. Obana,
K. Tanaka,
P. Wanderer,
A. Yamamoto
[show abstract]
[hide abstract]
ABSTRACT: Superconducting combined function magnets will be utilized for the 50 GeV-750 kW proton beam line for the J-PARC neutrino experiment and an R&D program has been launched at KEK. The magnet is designed to provide a combined function with a dipole field of 2.59 T and a quadrupole field of 18.7 T/m in a coil aperture of 173.4 mm. A single layer coil is proposed to reduce the fabrication cost and the coil arrangement in the 2D cross-section results in left-right asymmetry. This paper reports the design study of the magnet.
IEEE Transactions on Appiled Superconductivity 07/2004; · 1.04 Impact Factor
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T. Nakamoto,
Y. Ajima,
T. Fujii,
E. Hashiguchi, N. Higashi,
H. Hirano,
M. Iida,
T. Kanahara,
N. Kimura,
S. Murai, [......],
H. Ohhata,
N. Ohuchi,
T. Orikasa,
T. Shintomi,
S. Sugawara,
K. Sugita,
K. Tanaka,
A. Terashima,
K. Tsuchiya,
A. Yamamoto
[show abstract]
[hide abstract]
ABSTRACT: The MQXA superconducting low-beta quadrupole magnets for the LHC interaction regions are required to generate a field gradient of up to 215 T/m at 1.9 K along an effective magnetic length of 6.37 m. After completion of an R&D program on short models and full length prototypes, the series production of magnets has started, with to date five series magnets subsequently tested at KEK. Basic characteristics such as normal training, subsequent full energy dump, thermal cycle, ramp rate dependence and temperature dependence have been studied and results indicate that magnets have satisfactory quench performance. Magnetic field measurements performed at 1.9 K show the field quality to be uniform and to satisfy the stringent beam optics requirements.
IEEE Transactions on Appiled Superconductivity 07/2003; · 1.04 Impact Factor
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N. Ohuchi,
Y. Ajima, N. Higashi,
M. Iida,
N. Kimura,
T. Nakamoto,
T. Ogitsy,
H. Ohhata,
T. Shintomi,
S. Sugawara, [......],
K. Tanaka,
A. Terashima,
K. Tsuchiya,
A. Yamamoto,
T. Fujii,
T. Kanahara,
E. Hashiguchi,
S. Murai,
W. Odajima,
T. Orikasa
[show abstract]
[hide abstract]
ABSTRACT: KEK has developed a superconducting quadrupole magnet, MQXA, for the LHC interaction region. This magnet is required to generate an operating field gradient of 215 T/m in the magnet bore of 70 mm and have an effective magnetic length of 6.37 m. For the accelerator operation, sixteen MQXA magnets will be installed in total for four interaction regions, and the cold tests of ten MQXA magnets of them have been completed. These ten magnets had good quench performance and satisfactory field quality for the requirement of beam optics. This paper describes the production quality and the magnet performance of the MQXA magnets.
Particle Accelerator Conference, 2003. PAC 2003. Proceedings of the; 06/2003
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T. Ogitsu,
T. Nakamoto,
N. Ohuchi,
Y. Ajima,
E. Burkhardt, N. Higashi,
H. Hirano,
M. Lida,
N. Kimura,
H. Ohhata,
K. Tanaka,
T. Shintomi,
A. Terashima,
K. Tsuchiya,
A. Yamamoto,
T. Orikasa,
S. Murai,
O. Oosaki
[show abstract]
[hide abstract]
ABSTRACT: The development of the LHC low-beta insertion quadrupole magnets has been conducted at KEK since 1996. After the successful development of short model magnets, the first prototype magnet has been built by Toshiba and is tested at KEK. Although the quench performance and the field quality of the magnet are satisfactory, a design problem is found in one of the end spacers. The problem increases the risk of a turn-to-turn and in fact causes shorts in the second prototype magnet, and in the trial coil of the first production magnet. The design is modified and the problem appears to be resolved. The construction of the production magnets is now started and lasts till the summer of 2004.
IEEE Transactions on Appiled Superconductivity 04/2002; · 1.04 Impact Factor
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T. Nakamoto,
T. Orikasa,
Y. Ajima,
E.E. Burkhardt,
T. Fujii,
E. Hashiguchi, N. Higashi,
H. Hirano,
T. Kanahara,
N. Kimura, [......],
W. Dajima,
T. Ogitsu,
N. Ohuchi,
O. Oosaki,
T. Shintomi,
K. Sugita,
K. Tanaka,
A. Terashima,
K. Tsuchiya,
A. Yamamoto
[show abstract]
[hide abstract]
ABSTRACT: Superconducting low-beta quadrupole magnets for the LHC insertion regions are being developed at KEK as part of the collaboration between CERN and KEK. Magnet production technology developed at KEK has been transferred to a manufacturer of production magnets. In order to verify the production technology, fabrication jigs, tools, and procedures, the first full-scale prototype, MQXA-P1, was fabricated. Mechanical characteristics of MQXA-P1 were measured during the magnet assembly process, and it satisfied specifications needed for the production magnets. The validity of the magnet design and fabrication method was confirmed.
IEEE Transactions on Appiled Superconductivity 04/2002; · 1.04 Impact Factor
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[show abstract]
[hide abstract]
ABSTRACT: High gradient 70 mm aperture superconducting low-beta quadrupole
magnets have been developed at KEK as part of the collaboration between
CERN and KEK for the Large Hadron Collider (LHC). After development of
two 1 m model magnets, the third model magnet with the new coil design
was built and excitation tests were completed. The third model
successfully reached the design field gradient of 240 T/m and showed
training memory after full thermal cycles. Other quench tests were
performed and it was verified that the third model exhibited reliable
quench performance and sufficient safety margin during operation
IEEE Transactions on Appiled Superconductivity 04/2001; · 1.04 Impact Factor
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T. Shintomi,
Y. Ajima,
E.E. Burkhardt,
T. Haruyama, N. Higashi,
M. Iida,
N. Kimura,
S. Murai,
T. Nakamoto,
T. Ogitsu, [......],
N. Ohuchi,
A. Orikasa,
O. Osaki,
R.J.M.Y. Ruber,
K. Sugita,
K. Tanaka,
A. Terashima,
K. Tsuchiya,
A. Yamamoto,
H. Yamaoka
[show abstract]
[hide abstract]
ABSTRACT: Development of the LHC low-β insertion quadrupole magnet has
been in progress at KEK since 1995 as a cooperative program between CERN
and KEK. Five 1-m short model magnets have been fabricated and three of
them have been tested. From the various test results of the first two
models, the coil configuration was further optimized to reduce the
higher magnetic field harmonic coefficients. The cold test of the third
model showed satisfactory performances of the field harmonics. After
this R&D work, the authors are at a stage for the fabrication of two
prototype magnets which have the same scale as the production magnets.
The status of the R&D for the LHC low-beta insertion quadrupole
magnet at KEK is described
IEEE Transactions on Appiled Superconductivity 04/2001; · 1.04 Impact Factor
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A. Yamamoto,
Y. Ajima,
E. Burkhardt, N. Higashi,
H. Hirano,
M. Iida,
N. Kimura,
T. Nakamoto,
T. Ogitsu,
H. Ohhata,
N. Ohuchi,
R. Ruber,
T. Shintomi,
K. Tanaka,
A. Terashima,
K. Tsuchiya,
K. Sugita,
S. Murai,
T. Orikasa,
O. Osaki
[show abstract]
[hide abstract]
ABSTRACT: Development of low-β quadrupole magnets for the LHC beam
interaction regions has been carried out. The magnet is designed with a
field gradient of 240 T/m in a coil aperture of 70 mm, and is to be
operated at ⩽215 T/m with absorption of beam loss heating. Three 1-m
models with the final design have been developed and tested with
satisfying requirements of field quality and training characteristics. A
full-scale (6.3-m) prototype has been developed, and is being tested.
Progress of the LHC low-β quadrupole development at KEK is reported
Particle Accelerator Conference, 2001. PAC 2001. Proceedings of the 2001; 02/2001
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T. Nakamoto,
A. Yamamoto,
K. Tsuchiya,
Y. Ajima,
E. Burkhardt,
T. Haruyama, N. Higashi,
M. Iida,
N. Kimura,
T. Ogitsu,
I. Ohhata,
N. Ohuchi,
T. Shintomi,
K. Tanaka,
A. Terashima
[show abstract]
[hide abstract]
ABSTRACT: Two models of the high gradient 70 mm aperture superconducting
low-β quadrupole magnets were developed at KEK as part of the
collaboration between CERN and KEK for the Large Hadron Collider (LHC).
The training tests of both model magnets have been carried out at 1.9 K
and both models successfully reached the design field gradient of 240
T/m, and the training memory partially remained after thermal cycles.
General characteristics of the training curve for the models seemed to
be similar. In this paper, training results of the model magnets is
described and discussed
IEEE Transactions on Appiled Superconductivity 04/2000; · 1.04 Impact Factor
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[show abstract]
[hide abstract]
ABSTRACT: The development of high-gradient superconducting quadrupole
magnets for the LHC interaction regions has been carried out. The
mechanical design has been optimized with the two-shell coil structure
tightly fixed by thin non-magnetic collars and by iron-yoke with keys.
The mechanical rigidity is fully achieved at room temperature. The paper
describes the mechanical design characteristics and analysis of
mechanical tolerances and the influence on the field quality
IEEE Transactions on Appiled Superconductivity 04/2000; · 1.04 Impact Factor
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T. Nakamoto,
K. Tanaka,
A. Yamamoto,
K. Tsuchiya,
E. Barkhardt, N. Higashi,
N. Kimura,
T. Ogitsu,
N. Ohuchi,
K. Sasaki,
T. Shintomi,
A. Terashima,
G.A. Kirby,
R. Ostojic,
T.M. Taylor
[show abstract]
[hide abstract]
ABSTRACT: A one meter model of the high gradient 70 mm aperture
superconducting low-β quadrupole has been developed at KEK. The
design field gradient is 240 T/m at a current 7677 A with a
superconducting load line ratio of 92% and peak field of 9.64 T in the
coil. A first series of training tests of the magnet was carried out at
1.9 K including a full thermal cycle to room temperature. The highest
quench current was 8007 A corresponding to a field gradient of 250 T/m.
The magnet was subsequently reassembled to improve its longitudinal
mechanical structure. In this paper, quench characteristics and
mechanical behavior of the first model magnet are presented
IEEE Transactions on Appiled Superconductivity 07/1999; · 1.04 Impact Factor
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T. Shintomi,
T. Nakamoto, N. Higashi,
N. Kimura,
T. Ogitsu,
K. Tanaka,
A. Terashima,
K. Tsuchiya,
A. Yamamoto,
A. Orikasa,
K. Makishima,
N. Siegel,
D. Leroy,
R. Perin
[show abstract]
[hide abstract]
ABSTRACT: The 56 mm single aperture superconducting dipole model with a
5-block coil configuration was reassembled and tested to investigate the
full support of electromagnetic forces using a high-manganese steel
collar structure without mechanical contribution from an iron yoke. The
reassembled model, which has a gap between the high manganese steel
collar and the horizontally split iron yoke, reached a central field of
9 tesla (93% of short sample) at the first quench and attained the short
sample limit with a few following quenches. The test results of the
training quenches and the mechanical behavior after the modification are
described
IEEE Transactions on Appiled Superconductivity 07/1999; · 1.04 Impact Factor
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T. Shintomi,
A. Yamamoto,
Y. Doi,
T. Haruyama, N. Higashi,
H. Kawamata,
S.W. Kim,
N. Kimura,
V. Kovachev,
T. Nakamoto, [......],
T. Ogitsu,
K. Tanaka,
A. Terashima,
K. Tsuchiya,
R. Perin,
D. Leroy,
S. Kato,
K. Makishima,
T. Orikasa,
A. Tanaka
[show abstract]
[hide abstract]
ABSTRACT: A 56 mm single aperture superconducting dipole model magnet, which
is one of the frameworks of the LHC collaboration between KEK and CERN,
has been developed. A central field of 8.65 T is provided at a load line
ratio of 90% with a 5 block coil wound with NbTi superconducting cables.
The magnet has a straight section of 0.8 m and a total length of 1.2 m.
The distinctive features of the magnet are a magnetically symmetrical
configuration being applicable to the twin aperture magnet and
mechanical consideration sharing the magnetic forces with a high
manganese steel collar and a horizontally split iron yoke. The magnet
showed almost no training at 4.4 K. The first quench current at 1.8 K
was 91% of the short sample I<sub>c</sub> and the magnet reached a
central magnetic field of 8.8 T. Finally it could be excited with the
current of more than 99% of the short sample limit which corresponds to
a central field of 9.63 T
IEEE Transactions on Appiled Superconductivity 07/1997; · 1.04 Impact Factor
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A. Yamamoto,
K. Tsuchiya, N. Higashi,
T. Nakamoto,
T. Ogitsu,
N. Ohuchi,
T. Shintomi,
A. Terashima,
G. Kirby,
R. Ostojic,
T.M. Taylor
[show abstract]
[hide abstract]
ABSTRACT: The conceptual design study of a high gradient superconducting
insertion quadrupole magnet has been carried out in collaboration
between KEK and CERN for the Large Hadron Collider (LHC) to be built at
CERN. A model magnet design has been optimized to provide a nominal
design field gradient of 240 T/m with a bore aperture of 70 mm and an
operational field gradient of 225 T/m at 1.9 K under radiation
environment with a deposition of several watts per meter in the
superconducting coils. The design and its process are discussed
IEEE Transactions on Appiled Superconductivity 07/1997; · 1.04 Impact Factor
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A. Yamamoto,
T. Shintomi,
N. Kimura,
Y. Doi,
T. Haruyama, N. Higashi,
H. Hirabayashi,
H. Kawamata,
Seog-Whan Kim,
T.M. Kobayashi, [......],
N. Ohuchi,
K. Tanaka,
A. Terashima,
K. Tsuchiya,
H. Yamaoka,
G. Brianti,
D. Leroy,
R. Perin,
S. Mizumaki,
S. Kato
[show abstract]
[hide abstract]
ABSTRACT: A single aperture dipole magnet has been developed with a design
magnetic field of 10 tesla by using Nb-Ti/Cu conductor to be operated at
1.8 K in pressurized super fluid helium, The magnet features double
shell coil design by using high keystone Rutherford cable and compact
non-magnetic steel collars to be adaptable in split/symmetric
coil/collar design for twin aperture dipoles. A design central magnetic
field of 10 tesla has been successfully achieved in excitation at 1.95 K
in pressurized superfluid helium. Test results of the magnet with a
summary of the design and fabrication are presented
IEEE Transactions on Magnetics 08/1996; · 1.36 Impact Factor
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A. Yamamoto,
T. Shintomi, N. Higashi,
H. Hirabayashi,
H. Kawamata,
Naihao Song,
A. Terashima,
H. Yamaoka,
S. Kawabata,
G. Brianti, [......],
R. Perin,
A. Siemko,
L. Walckiers,
M. Hirano,
T. Origasa,
K. Makishima,
I. Inoue,
M. Ikeda,
S. Meguro,
M. Kondo
[show abstract]
[hide abstract]
ABSTRACT: A twin aperture dipole magnet has been developed with a feature of symmetric, separate coil/collar design in a R&D cooperation between CERN and KEK towards the LHC (Large Hadron Collider) project. The magnet reached 8.1 T at 4.2 K and 9.6 T at 1.8 K in the training test. Development of the magnet and test results are discussed. Design study of a new 56 mm φ twin aperture dipole is also discussed.
IEEE Transactions on Appiled Superconductivity 07/1995; · 1.04 Impact Factor
