Superconducting high field solenoids for hybrid systems

Hybrid magnet systems are used to produce high steady magnetic field (above 30 T in the most recent systems) in a relatively large bore (larger than 30 mm). The strong magnetic coupling existing between the two magnets represents the most critical aspect in designing such systems. In particular, every fault in the resistive magnet translates in a combination of fast magnet field transient and large mechanical forces applied to the superconducting winding. The requirement to withstand such severe transient conditions has a significant impact on the superconducting magnet design. In an attempt to fulfill such requirement, for the already produced or still-under-development hybrid systems, different design options have been selected by the manufacturers of the superconducting magnet. Main purpose of this paper is to describe and to compare such design options by giving an overview of the state-of-the-art on superconducting high field solenoids for hybrid systems. Where possible, a summary of the operational experience gained on such magnets will be reported.