The measurement and theoretical calculation of quench velocities within large fully epoxy impregnated superconducting coils

The velocity of normal region propagation was measured in a 2-m diameter superconducting coil. The measured data made with small sense coils, did not agree very well with theories which have been used for the last 15 years. An adiabatic quench propagation theory, which takes into account the properties of both the superconductor and the matrix material and which assumes there is no heat transfer out of the wire, was found to agree with the experimental measurements. Both the theory and experimental measurements are given in this paper.