Stability analysis of the LHC cables

The commissioning and operation of the LHC accelerator calls for better understanding of the stability margin of its superconducting magnets with respect to the perturbation spectrum expected during operation, such as wire motion, AC loss during ramps and in particular beam induced heat depositions. In this paper, the stability analysis of the cables for the LHC dipole for transient heat deposition is reported. The sensitivity of the stability margin to the parameters of the model is investigated and discussed. In particular, the helium content in the cable is shown to have a large impact on stability. In fact, we find that the most important parameter is the heat transfer into helium II and helium I. Furthermore, we quantify the influence of the interstrand thermal and electrical coupling on the cable stability in the several examples reported.