400 MHz/89 mm actively shielded high resolution NMR magnet

The first actively shielded high resolution NMR magnet was developed and successfully demonstrated. The magnet has excellent field homogeneity in a very large volume and lineshape characteristics exceed the specifications of the standard magnets. Shielding performance is also outstanding, with the 5 G line located only 1 m radially and 1.5 m axially from the magnet center. We are reporting the magnet specifications, details of the design and fabrication, magnet training, field mapping and lineshape results.