The influence of thermal disturbance duration on the stability of superconducting windings with extremely large heat capacity dopants

• Published in: Superconductor science & technology 2008-02, Vol.21 (2), p.025018-025018 (5)
• Main Authors: Keilin, V E, Kovalev, I A, Kruglov, S L, Shutova, D I
• Format: Article
• Language: English
• ISSN: 0953-2048; 1361-6668
• DOI: 10.1088/0953-2048/21/2/025018

Our goal was to investigate the dependence of the stability of superconducting windings with extremely large heat capacity dopants on the thermal disturbance duration. The critical energies of the thermal disturbances were measured for two NbTi coils. One of the coils was doped with 5 vol% of Gd2O2S; the other was practically identical to the first, but without a large heat capacity dopant. Both coils were wound using the 'wet-winding' process. The thermal disturbances were generated with alternate magnetic field pulses localized in the innermost winding turns. The threshold pulse parameters were used to calculate the heat dissipated in the wire. In was found that the critical energy densities reach their adiabatic limit (enthalpy margin averaged across the winding) at 1.4 ms for the comparison coil and at 20 ms for the doped coil. The gain in the energy densities was observed in the whole duration range (0.2-34 ms) and at temperature margins (0.25-1 K), but a meaningful (about 30%) increase of energy densities started from about 0.8 ms characteristic disturbance time.