Optimum copper to superconductor ratio in cables for superconducting magnets at 1.9 K

In this paper the optimum copper to superconducting ratio is calculated to prevent quenching for superconducting cables used in accelerator magnets like the LHC dipoles, operating in superfluid helium at 1.9 K. The duration of the perturbations leading to a quench are estimated from flax measurements made with pickup coils in the LHC dipole models. The optimum copper to superconducting ratio is then found by studying the minimum quench energy and the influence of the length and the duration of the perturbation and heat transfer to the surroundings. A comparison is made of the behaviour at temperatures of 1.9 and 4.3 K.<
>