Design, manufacture, and test of a large bore cryogen-free magnet

A large superconducting cryogen-free magnet has been designed, manufactured and tested. The magnet reached 4.1 T in the 430 mm room temperature bore with a ramp time of 35 min. The magnet is cooled by a two-stage GM cryocooler. The magnet can be rotated on a support frame to be operated with either horizontal or vertical bore. The stored energy of 1 MJ can safely be handled during a quench. Homogeneity, cool down as well as quench properties confirmed the design values. The magnet is now being operated by the end user.