Losses and stability in superconducting wire in a.c. fields with frequencies up to 2.5 kHz
| Autor: | I.F. Voloshin, I.M. Hlasnik, L.M. Fisher, E.Yu. Klimenko, N.N. Martovetsky |
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| Rok vydání: | 1994 |
| Předmět: |
Superconductivity
Materials science Condensed matter physics Superconducting wire General Physics and Astronomy engineering.material Instability Magnetic field law.invention Electromagnetic coil law engineering General Materials Science Alternating current Electrical conductor Overheating (electricity) |
| Zdroj: | Cryogenics. 34:83-87 |
| ISSN: | 0011-2275 |
| DOI: | 10.1016/0011-2275(94)90057-4 |
| Popis: | Results are presented of losses and stability measurements in a small superconducting (SC) coil with an alternating current at frequencies up to 2.5 kHz. The mutual influence of losses and instability on the maximum attainable current is studied and discussed. It is shown that there are different modes of quench. SC wire can go to the normal state due to the development of instability with almost no overheating over the ambient temperature. In another mode, overheating over the current sharing temperature occurs due to losses under stable conditions. The experimental results agree with a recently developed stability theory for composite wires, taking into account the smoothness of the transition characteristic and its influence on stability. This theory explains why cryogenically unstable SC wires work at currents close to the critical current, why SC wires are more stable at lower rates of field change and current charge rate and why wires with a smoother transitional characteristic are generally more stable than SC wires with sharp transitions to the normal state. The theory thus allows us to approach the problem of the relationship between losses and stability. |
| Databáze: | OpenAIRE |
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