JOPSS - Search Results

Journal Articles

Magnetic field stabilization by temperature control of an azimuthally varying field cyclotron magnet

Okumura, Susumu; Arakawa, Kazuo; Fukuda, Mitsuhiro; Nakamura, Yoshiteru; Yokota, Wataru; Ishimoto, Takayuki*; Kurashima, Satoshi; Ishibori, Ikuo; Nara, Takayuki; Agematsu, Takashi; et al.

Review of Scientific Instruments, 76(3), p.033301_1 - 033301_6, 2005/03

https://doi.org/10.1063/1.1858578

Times Cited Count：9 Percentile：41.66(Instruments & Instrumentation)

A magnetic field drift, gradual decrease of the order of 10 $^{-4}$ in several tens of hours, was observed with the beam intensity decrease in an operation of an azimuthally-varying-field (AVF) cyclotron. From our experimental results, we show that the temperature increase of the magnet iron by the heat transfer from the excitation coils can induce such change of the magnetic field as to deteriorate the beam quality. The temperature control of the magnet iron was realized by thermal isolation between the main coil and the yoke and by precise control of the cooling water temperature of the trim coils attached to the pole surfaces in order to prevent temperature change of the magnet iron. The magnetic field stability of 510 $^{-6}$ and the beam intensity stability of 2% have been achieved by this temperature control.

Journal Articles

Radiation-induced thermoelectric sensitivity in the mineral-insulated cable of magnetic diagnostic coils for ITER

Nishitani, Takeo; Vayakis, G.*; Yamauchi, Michinori*; Sugie, Tatsuo; Kondoh, Takashi; Shikama, Tatsuo*; Ishitsuka, Etsuo; Kawashima, Hisato

Journal of Nuclear Materials, 329-333(Part2), p.1461 - 1465, 2004/08

https://doi.org/10.1016/j.jnucmat.2004.04.252

Times Cited Count：16 Percentile：68.16(Materials Science, Multidisciplinary)

no abstracts in English

JAEA Reports

Analysis program for magnetic field, inductance of air-core coils; COIL

Yoshida, Kiyoshi; Isono, Takaaki; Sugimoto, Makoto; Okuno, Kiyoshi

JAERI-Data/Code 2003-014, 38 Pages, 2003/08

JAERI-Data-Code-2003-014.pdf:2.71MB

In case of designing a superconducting coil (SC), one must calculate a magnetic field (B) and its inductance (L) many times in order to arrange proper design parameters of SC because there are many design parameters to evaluate. SC cannot be designed by the optimum condition if a B and L can't be computed easily. When SC is energized, measurement values of B and L are very well agreed with calculated values. The B and L of the coil that doesn't contain a ferromagnetic material can be calculated by the numerical integration. The analytic method were developed and established in 1970's. This paper shows the calculation program COIL that has been developed by applying this analytic method in JAERI. COIL is qualified by the comparison between measured and calculated values in case of several real SC. COIL is specified to analyze SC of tokamak device. Even for a complicated tokamak device, B and L can be calculated in several minutes by the high performance of the recent personal computer. COIL contributes to design SC for ITER and others.

Journal Articles

Pressure drop characteristics of Nb $_{3}$ Al cable-in-conduit conductor under electromagnetic force; Relation between pressure drop characteristics and cable stiffness

Hamada, Kazuya; Matsui, Kunihiro; Takahashi, Yoshikazu; Nakajima, Hideo; Kato, Takashi; CS Model Coil Test Group

Teion Kogaku, 38(8), p.417 - 424, 2003/08

https://doi.org/10.2221/jcsj.38.417

As one of the R&D of ITER. a hydraulic performance of Nb $_{3}$ Al insert coil was measured and compared with other Nb $_{3}$ Sn conductors. It seems that a longer twist pitch will promote a triangle helium flow space among 4th twist stage cables, jacket and center channel and contribute reduction of pressure drop. Under 500 kN/m of the electromagnetic force, the pressure drop of the Nb $_{3}$ Al insert decreased by approximately 5%. Nb $_{3}$ Al conductor indicated quit rigid characteristic under the electromagnetic force and suitable for future magnet with higher magnetic field and current.

Journal Articles

Temperature control of a cyclotron magnet for stabilization of the JAERI AVF cyclotron beam

Okumura, Susumu; Arakawa, Kazuo; Fukuda, Mitsuhiro; Nakamura, Yoshiteru; Yokota, Wataru; Ishimoto, Takayuki*; Kurashima, Satoshi; Ishibori, Ikuo; Nara, Takayuki; Agematsu, Takashi; et al.

AIP Conference Proceedings 600, p.330 - 332, 2001/00

https://doi.org/10.1063/1.1435267

Frequent corrections of the magnetic field of the JAERI AVF cyclotron were required for keeping a beam current constant during long time operation. We observed correlation between the magnetic field and the temperature of the cyclotron magnet yoke by measuring the magnetic field with an NMR probe and the temperature with platinum resistance thermometers. The unstable phenomenon of a cyclotron beam was induced by temperature change in the magnet yoke caused mainly by thermal conduction from the main coil. To restrain the thermal conduction to the yoke, we have inserted temperature controlled copper plates between the yoke and the main coil. In addition, a temperature control system of the cooling water of the trim coils has been installed independent of the total cooling system for controlling the pole tip temperature. An optimum condition of the temperature control systems for stabilizing the magnetic field has been investigated.

Journal Articles

Stabilization of cyclotron magnetic field strength by means of magnet temperature control

Okumura, Susumu; Kurashima, Satoshi; Ishimoto, Takayuki*; Yokota, Wataru; Arakawa, Kazuo; Fukuda, Mitsuhiro; Nakamura, Yoshiteru; Ishibori, Ikuo; Nara, Takayuki; Agematsu, Takashi; et al.

Proceedings of 13th Symposium on Accelerator Science and Technology, p.283 - 285, 2001/00

no abstracts in English

JAEA Reports

Non-uniform current distribution in a force-cooled superconductor under changing magnetic field

Koizumi, Norikiyo

JAERI-Research 99-076, p.198 - 0, 2000/02

JAERI-Research-99-076.pdf:13.19MB

no abstracts in English

JAEA Reports

Irradiation effects on plasma diagnostic components

Nishitani, Takeo; ; Ikeda, Yujiro; Ishitsuka, Etsuo; Kakuta, Tsunemi; Kasai, Satoshi; Kawamura, Hiroshi; Morita, Yosuke; Nagashima, Akira; Nakamichi, Masaru; et al.

JAERI-Research 98-053, 105 Pages, 1998/10

JAERI-Research-98-053.pdf:4.78MB

no abstracts in English

JAEA Reports