Stability of the superconducting wires-modern state of the theory

Klimenko, E.Yu.; Martovetsky, N.

doi:10.1109/20.120009

Cited by 13 publications

(2 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In general, the N-value as a measure of stability and broadness of transition is sometimes misleading. The measure of stability in superconductors is the level of electrical field at take-off; the higher the electrical field, the higher the stability [7]. The take-off field can be expressed as:…”

Section: Description Of the Electrical Growth In Superconductors With...mentioning

confidence: 99%

Correlation between degradation and broadness of the transition in CICC

Martovetsky¹

2013

Supercond. Sci. Technol.

View full text Add to dashboard Cite

Cable in Conduit Conductor (CICC) performance is characterized in terms of relationships involving the electric field (E), voltage (V), temperature (T), current (I), magnetic field (B), and strain. Development of the electrical field in the V-T or V-I transitions in CICC is exponential, and in the coordinates log E vs T or log E vs I looks as a straight line.ITER Nb3Sn CICCs show degradation of properties versus load cycles that could be attributed to plastic deformation of the Nb3Sn strands or fracture of the superconducting filaments. The degradation is expressed in terms of reduction of the current sharing temperature Tcs or critical current Ic, respectively. It was noticed long ago that degradation is accompanied by a significant broadening of the V-T or V-I transition, that looks like a change in the slope in the semi-log coordinate plot. This paper presents some systematic observations of correlations between the critical parameters and broadness of the transition in many conductors tested in CICC. In most cases, the broadness of the transition seems to be a more sensitive indicator of the conductor damage even in cases when Tcs degradation is not clearly seen. Tcs degradation typically becomes obvious later in the cycling, especially after warm up and following cooldown and more cycling.In some cases, a CICC manifests temporary or even a permanent growth of Tcs with load cycles, especially in the latest measurements of the CS conductors with short twist pitches. A possible mechanism of degradation that allows qualitative explanation of this phenomenon is discussed, which is supported by the voltage measurements on the cable in TFUS1 with the voltage taps penetrating the jacket to the cable. IntroductionSince middle of 1990's, when an intensive development of the Nb3Sn CICC took place, a wealth of data on degradation of the high current Nb3Sn CICC has been developed. However, this knowledge has not yet produced a quantitative correlation that would allow predicting performance of the CICC from the properties of the strand, cabling pattern, void fraction and jacket properties and geometry.

show abstract

Section: Description Of the Electrical Growth In Superconductors With...mentioning

confidence: 99%

Correlation between degradation and broadness of the transition in CICC

Martovetsky¹

2013

Supercond. Sci. Technol.

View full text Add to dashboard Cite

show abstract

“…The existing tendency to use low current density conductors for high stored energy magnets does not seem to be well founded. In fact, a transition curve smoothness provides high conductor stability to any magneto-thermal excitations [1], rigid fastening of a conductor to a reinforcing element is a better way to exclude thermo-mechanical excitations than attempts to absorb them with high heat capacity of the conductor. In addition, in the case of a reliably operating magnet there is no need to use an external resistor as a method of magnet protection.…”

Section: Introductionmentioning

confidence: 99%

Prediction of the quench current of a large magnet with a small model test

Klimenko

Novikov

2002

IEEE Trans. Appl. Supercond.

Self Cite

View full text Add to dashboard Cite

The quench current of any large nonsteadily stabilized magnet under design can be predicted by testing of a relatively small model. The model should reproduce the main features of the design and the manufacturing technique as well as the temperature margin and the amplitude of thermo-mechanical excitations inherent in the magnet being designed and dependent on the stress level. Usually it is unfeasible to reach a high stress level in a small model. However it is possible when external forces are used. An experiment with a superconducting force generator is described here. It has allowed the testing of two different models of a 50 MJ coil under high compressive load, to choose the best and to determine the necessary temperature margin for the large coil.

show abstract

The system and test results for the Tokamak T-15 magnet

Chernoplekov

1993

Fusion Engineering and Design

View full text Add to dashboard Cite

Stability of the superconducting wires-modern state of the theory

Cited by 13 publications

References 15 publications

Correlation between degradation and broadness of the transition in CICC

Correlation between degradation and broadness of the transition in CICC

Prediction of the quench current of a large magnet with a small model test

The system and test results for the Tokamak T-15 magnet

Contact Info

Product

Resources

About