Impact of radiation heat transfer on superconductor stability
Harald Reiss and Oleg Yu. Troitsky
Standard stability calculations for superconductors following the traditional Stekly, adiabatic or dynamic stability models apply purely solid thermal conduction mechanism and derive predictions under (quasi-) stationary and adiabatic conditions. In the present paper, also thermal radiative heat transfer in the superconducting solid and pool boiling to a coolant is taken into account. The analysis applies a combined Monte Carlo/Finite Element model to calculate transient fields of temperature, critical current densities and stability functions under single, isolated disturbances that could interrupt zero loss current transport and lead to a quench. The Monte Carlo/Finite element method is applied to a 1G filament, high temperature superconductor. Results obtained for maximum, zero loss current transport in the filament are different up to 30% from solutions achieved with standard, solely solid conduction heat transfer. Release of mechanical strain energy or of impinging particle radiation are taken as examples for single, isolated point-like disturbances. Deviations may be larger if other kinds of disturbances have to be considered.
Keywords: superconductor, disturbance, stability, thermal radiation, combined Monte Carlo/Finite Element simulation, fault current limiter