Coupling loss time constants in full-size Nb{sub 3}Sn CIC model conductors for fusion magnets

Nijhuis, A; Kate, H H.J. ten; Duchateau, J L

Title: Coupling loss time constants in full-size Nb{sub 3}Sn CIC model conductors for fusion magnets

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Abstract

The cable-in-conduit conductor for the ITER coils have to perform at magnetic fields up to 13 T under the conditions of normal high ramp rates as well as extreme magnetic pulses during a plasma disruption. Modelling, ac loss computations and design optimisations require to understand and identify the coupling loss time constants in multistage cables. For this AC loss measurements are performed on jacketed full size Nb{sub 3}Sn cable-in-conduit conductors. A transverse sinusoidal magnetic field is applied on the conductor to determine the coupling loss time constants with a calorimetric method. Moreover the decay of the coupling currents after a linear ramp is monitored with compensated pick-up coils. A comparison is made between the results obtained with both measuring methods. It appears that the n.{tau} value taken from the slope of the loss versus frequency curve in the low frequency limit has only a meaning at these low frequencies. At higher rates of magnetic field change which are relevant to describe a plasma disruption, internal shielding effects are not negligible and a different approach has to be used. The experimental results and a straightforward model are presented to find the coupling current time constants of this type of conductors. Itmore »« less

Authors:

Nijhuis, A; Kate, H H.J. ten ^[1]; Duchateau, J L ^[2]

Univ. of Twente, Enschede (Netherlands)
EURATOM-CEA, Cadarache (France); and others

Publication Date:: Sun Jun 01 00:00:00 EDT 1997

OSTI Identifier:: 482144

Report Number(s):: CONF-950722-
Journal ID: ACYEAC; ISSN 0065-2482; TRN: 97:010621

Resource Type:: Journal Article

Journal Name:: Advances in Cryogenic Engineering

Additional Journal Information:: Journal Volume: 42B; Conference: CEC/ICMC `95: cryogenic engineering conference and international cryogenic materials conference, Columbus, OH (United States), 17-21 Jul 1995; Other Information: PBD: 1997

Country of Publication:: United States

Language:: English

Subject:: 70 PLASMA PHYSICS AND FUSION; 36 MATERIALS SCIENCE; SUPERCONDUCTING CABLES; AC LOSSES; RELAXATION TIME; ITER TOKAMAK; SUPERCONDUCTING MAGNETS; NIOBIUM BASE ALLOYS; TIN ALLOYS

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                    Nijhuis, A, Kate, H H.J. ten, and Duchateau, J L. Coupling loss time constants in full-size Nb{sub 3}Sn CIC model conductors for fusion magnets.  United States: N. p., 1997. 
        Web.

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                    Nijhuis, A, Kate, H H.J. ten, & Duchateau, J L. Coupling loss time constants in full-size Nb{sub 3}Sn CIC model conductors for fusion magnets.  United States.

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                    Nijhuis, A, Kate, H H.J. ten, and Duchateau, J L. 1997.  
        "Coupling loss time constants in full-size Nb{sub 3}Sn CIC model conductors for fusion magnets".  United States.

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@article{osti_482144,

  title        = {Coupling loss time constants in full-size Nb{sub 3}Sn CIC model conductors for fusion magnets},

  author       = {Nijhuis, A and Kate, H H.J. ten and Duchateau, J L},

  abstractNote = {The cable-in-conduit conductor for the ITER coils have to perform at magnetic fields up to 13 T under the conditions of normal high ramp rates as well as extreme magnetic pulses during a plasma disruption. Modelling, ac loss computations and design optimisations require to understand and identify the coupling loss time constants in multistage cables. For this AC loss measurements are performed on jacketed full size Nb{sub 3}Sn cable-in-conduit conductors. A transverse sinusoidal magnetic field is applied on the conductor to determine the coupling loss time constants with a calorimetric method. Moreover the decay of the coupling currents after a linear ramp is monitored with compensated pick-up coils. A comparison is made between the results obtained with both measuring methods. It appears that the n.{tau} value taken from the slope of the loss versus frequency curve in the low frequency limit has only a meaning at these low frequencies. At higher rates of magnetic field change which are relevant to describe a plasma disruption, internal shielding effects are not negligible and a different approach has to be used. The experimental results and a straightforward model are presented to find the coupling current time constants of this type of conductors. It is shown that several dominant time constants can exist that are associated with relatively small volume fractions of a cable.},

  doi          = {},

  url          = {https://www.osti.gov/biblio/482144},
  journal      = {Advances in Cryogenic Engineering},
number       = ,

  volume       = 42B,

  place        = {United States},

  year         = {Sun Jun 01 00:00:00 EDT 1997},

  month        = {Sun Jun 01 00:00:00 EDT 1997}

}

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