QUENCH PROTECTION AND DESIGN OF HIGH-FIELD SUPERCONDUCTING ACCELERATOR MAGNETS: THE ROLE OF DYNAMIC EFFECTS ON THE DIFFERENTIAL INDUCTANCE

Quench protection is one of the most challenging aspects during the design of high-field superconducting accelerator magnets. Quench is the superconducting-to-resistive transition of a superconducting magnet, during which the large stored energy is dissipated into heat in a small region, which warms up. Quench cannot be avoided, therefore each superconducting magnet needs a quench protection system.The inductance plays an important role during a quench: it is important to discharge the current flowing within the coils of the magnet as soon as possible, in order to reduce the temperature. In order to perform a reliable protection study, it is therefore important to model the inductance in the correct way. This work shows how the inductance in superconducting magnets is connected to transient effects typical of the superconductivity. An electromagnetic model is presented, and compared with experimental data. Moreover, the quench protection and the design of accelerator magnets is reported, with emphasis on the role of the inductance.This work is an important further step for the protection study of superconducting magnets, because it allows to understand some experimental evidences which could not be explained before. It is one of the first attempts of considering the inductance as a dynamic quantity during a quench, and it allows performing more reliable and realistic protection studies.