Field Stability and Homogeneity of 14-T Superconducting Split-Pair Magnet for Highly-Sensitive NMR Spectrometer

We have been developing a novel NMR spectrometer with two special features since 2003; the first is its superconducting split-magnet, and the second is its cryogenic solenoidal probe coil. Thus far, we have successfully developed the magnet with magnetic fields up to 14 T that has excellent field stability and homogeneity. The superconducting split-pair magnet has been operating for over two years without any quenching. This paper describes details on field stability and homogeneity under persistent-mode operation.