900 MHz wide bore NMR spectrometer magnet at NHMFL

The National High Magnetic Field Laboratory, in collaboration with Intermagnetics General Corporation, is in the process of fabricating a wide bore 900 MHz NMR magnet. The magnet is in many ways similar in concept to the typical high field NMR spectrometer magnet, employing Nb3Sn and NbTi conductors in a set of epoxy impregnated long solenoids plus compensation coils for uniformity. The magnet will operate at a temperature of 1.8K to produce a field of 21.1 T. The high field and large bore result in large mechanical stress in the coils and large magnetic stored energy. Innovations in the technology are introduced into the design to satisfy the requirements, including the manner of reinforcement of the windings and the active protection system. The design parameters of the magnet are presented. The technological solutions to the requirements of large high field magnets are discussed.