Thermal contraction of superconducting magnet materials

Gladky, V.N.; Veshchikov, A.T.; Escher, U.

doi:10.1016/0011-2275(95)90428-i

Cited by 5 publications

(2 citation statements)

References 2 publications

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“…Both the thermal contraction of different materials and the magnetic field will produce axial force in the coils, which causes axial stress along the width direction of the tapes [6], [7].…”

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confidence: 99%

Delamination Properties of YBCO Tapes Under Shear Stress Along the Width Direction

Liu

Zhu

Yang

et al. 2016

IEEE Trans. Appl. Supercond.

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In YBCO coils, the increased transport current density and magnetic field will induce larger electromagnetic force, and YBCO coated conductors (CCs) may suffer interlayer delamination by shear forces, which may give rise to performance degradation of the conductor. The delamination characteristics of YBCO CCs under shear stress should be well understood for better application of YBCO tapes to high-temperature superconducting equipment. This paper describes the experimental results for different delamination strength and critical current I c degradation behaviors of the YBCO CCs under shear stress at the unslit edge, center, and slit edge of the conductor. The results show that the average delaminated shear strengths of 4.9, 5.9, and 3.7 MPa are recorded for the unslit edge, center, and slit edge at room temperature, whereas 6.8, 7.2, and 5.1 MPa are recorded for the unslit edge, center, and slit edge at liquid nitrogen. The different degradation behaviors of I c under shear stress are related to the location where delamination occurs in the sample. According to the finite-element method analysis for the stress distribution of the conductor under shear stress, stress concentration leads to initial delamination of the conductor. The decrease of moment arm is suggested to reduce the effect of moment on the delamination test.

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confidence: 99%

Delamination Properties of YBCO Tapes Under Shear Stress Along the Width Direction

Liu

Zhu

Yang

et al. 2016

IEEE Trans. Appl. Supercond.

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“…Indeed, the unloaded height of a stack of insulated superconducting cable is ill-defined [9], equation (1) cannot be used for the evaluation of the thermal contraction coefficient of the stack in a direct manner. In fact, considering the stress-displacement curve presented in [7], at low pressure an increase of just 1 MPa (for instance from 0 MPa to 1 MPa) in the compression stress determines a strain of the same order of the thermal contraction of the stack [10][11][12], i.e. about 1 %.…”

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confidence: 99%

Thermal contraction measurements of the superconducting coil of the main magnets for the Large Hadron Collider

Ferracin¹,

Todesco²,

Tommasini³

et al. 2002

AIP Conference Proceedings

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We analyse the problem of defining and measuring the thermal contraction in the superconducting coil of the Large Hadron Collider main magnets. Since an unloaded coil length cannot be precisely defined, one has to use methods based on the pre-stress loss from room temperature to cryogenic temperature. A very strong dependence of the thermal contraction coefficient on the conventions used for defining coil deformations is discussed. Moreover, one finds different values of the thermal contraction coefficient according to the pressure imposed at room temperature before the cooling down. A pressure-dependent thermal contraction coefficient can be therefore worked out. ABSTRACTWe analyse the problem of defining and measuring the thermal contraction in the superconducting coil of the Large Hadron Collider (LHC) main magnets. Since an unloaded coil length cannot be precisely defined, one has to use methods based on the prestress loss from room temperature to cryogenic temperature. A very strong dependence of the thermal contraction coefficient on the conventions used for defining coil deformations is discussed. Moreover, one finds different values of the thermal contraction coefficient according to the pressure imposed at room temperature before the cooling down. A pressure-dependent thermal contraction coefficient can be therefore worked out.

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Thermomechanical properties of the coil of the superconducting magnets for the Large Hadron Collider

Couturier

Ferracin²,

Scandale³

et al. 2002

IEEE Trans. Appl. Supercond.

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Abstract-The correct definition and measurement of the thermomechanical properties of the superconducting cable used in high-field magnets is crucial to study and model the behavior of the magnet coil from assembly to the operational conditions. In this paper, the authors analyze the superconducting coil of the main dipoles for the Large Hadron Collider. They describe an experimental setup for measuring the elastic modulus at room and at liquid nitrogen temperature and for evaluating the thermal contraction coefficient. The coils exhibit strong nonlinear stressstrain behavior characterized by hysteresis phenomena, which decreases from warm to cold temperature, and a thermal contraction coefficient, which depends on the stress applied to the cable during cooldown.

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Thermal contraction of superconducting magnet materials

Cited by 5 publications

References 2 publications

Delamination Properties of YBCO Tapes Under Shear Stress Along the Width Direction

Delamination Properties of YBCO Tapes Under Shear Stress Along the Width Direction

Thermal contraction measurements of the superconducting coil of the main magnets for the Large Hadron Collider

Thermomechanical properties of the coil of the superconducting magnets for the Large Hadron Collider

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