| Popis: |
Normal zone propagation is examined in high T c superconducting (HTSC) thin film grown on Al 2 O 3 substrates. the transient heat equation is solved by a two-dimensional numerical model. In fact it appears that conventional analyses are inappropriate for this kind of HTSC system. The computational results indicate that the substrate, with its high value of thermal conductivity, is an efficient thermal shunt for the normal zone propagation in the thin film. This effect induces a significant increase in the quench velocity. Furthermore, the substrate is a good stabilizer, the minimum quench energy of the system is high for a current/far from the critical value/ c : in addition, the HTSC film is cooled efficiently. Thus the HTSC thin films deposited on a Al 2 O 3 substrate are very stable against a pulsed disturbance or an accidental transition (/⪡/ c ). |
