Title :
Study of quenching and recovery for superconducting wires and cylinders
Author :
Unal, A. ; Chyu, M.-C.
Author_Institution :
Dept. of Mech. Eng., Texas Tech. Univ., Lubbock, TX, USA
fDate :
3/1/1993 12:00:00 AM
Abstract :
The operational instability of a cylinder/wire-type superconductor subjected to an instantaneous linear thermal disturbance is investigated. The mechanism of loss and recovery of superconductivity is studied by calculating the instability parameter, Joule heating rate, and convective cooling rate based on a solution of the transient heat conduction equation with or without volumetric heating. The effects of operational current density and wire diameter on stability are investigated. A criterion is developed for the maximum current density in stable operation under thermal disturbance and the maximum current density for recovery after quenching. Data for NbTi superconductors are presented, and the results are compared with those for tape/film-type superconductors.<>
Keywords :
critical current density (superconductivity); fluctuations in superconductors; losses; niobium alloys; quenching (thermal); type II superconductors; Joule heating rate; NbTi superconductors; convective cooling rate; critical current density; instability parameter; linear thermal disturbance; loss mechanism; maximum current density; operational current density; operational instability; quenching; superconducting cylinders; superconducting wires; superconductivity recovery; thermal disturbance; transient heat conduction equation; volumetric heating; wire diameter; Cooling; Current density; Equations; Heat recovery; Niobium compounds; Stability; Superconducting filaments and wires; Superconducting films; Superconductivity; Thermal quenching;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
