Appendix A: Material Property Data for Quench Simulations

Abstract

On two occasions I have been asked,- " Pray, Mr. Babbage, if you put into the machine wrong figures, will the right answer come out? " I am not able rightly to apprehend the kind of confusion of ideas that could provoke such a question. C. Babbage (1791–1871). The numerical simulation of quenching superconducting magnets relies on the electrical and thermal properties of materials in a wide range of temper-atures and applied magnetic flux densities. The peak temperature in the coil is principally determined by the thermal conductivity λ and volumetric heat capacity ρc p of the conductors and the coolant. The electrical resistivity ρ of all magnet components is required for the calculation of ohmic heating and induced eddy currents. Remark: The empirical laws presented in this chapter shall be parsed as numerical-value expressions of the physical quantities expressed in SI units. We will write, for example, B ≡ {B} T as shorthand for the numerical value of the flux density expressed in tesla. In treating thermal, mechanical, and elec-trical properties, we must live with the ambiguity of the symbol ρ for both the mass density and electrical resistivity.