Hydraulic quench simulations in SSC dipole magnets

Abstract

Anomalously high quench velocities have been observed in long 40-mm-aperture SSC (Superconducting Super Collider) dipole magnets. The thermal conduction mechanism does not properly explain the observed quench velocities in long SSC dipole magnets. A helium hydraulic event within the insulated conductor provides a plausible explanation for observed velocities. Preliminary results of a coupled thermal conductive and hydraulic numerical model of a conductor quench event produce velocities comparable to observations. The normal operating conditions are force-flow cooling at four atmospheres and 4.35 K temperature. The model quench velocities are dependent upon ambient pressure and slow down under pool boiling conditions. Slower pool boiling velocities in the model do not explain observations in short SSC dipole test magnets which are operated at pool boiling conditions. >