Compact, Neon-Cryocooled NMR Magnets Assembled from Superconducting YBCO Annuli

The specific aims of this Phase 1 of a 2-Phase program to design, manufacture, and operate a prototype 200MHz/38mm 'bench-top' NMR 'annulus' magnet (in Phase 2: 300MHz/43mm and 500MHz/43mm magnets) are four-fold: 1) Design, manufacture, and operation of a 200MHz/38mm bore prototype 'NMR-class'' magnet based on an innovative design/operation concept that is particularly suited to a new type of persistent-mode NMR magnets for high-resolution 'micro-NMR' spectroscopy; 2) Demonstrate, with the prototype, the unique feature of the annulus magnet that permits the magnet to be energized at one site (manufacturer) and transported to another site (user), while the magnet maintains its NMR-quality magnetic field; 3) Complete and demonstrate a 'fieldtweaking'' technique that permits 'micro-tuning' of the supercurrent distributions of annuli and hence the field homogeneity; and 4) Demonstrate the system's unique cryogenic system that: a) keeps a volume of solid neon and the annulus magnet at a nominal operating temperature of 15 K; b) enables the energized annulus magnet to maintain its persistent-mode field over the range 15-24K during a cryocooler-free 'cooling-blank' period (~48 hours), when the energized magnet is shipped, or, if required, operated to provide a vibration-free environment for measurement. <P> Our 'high-field benchtop' annulus NMR magnet permits measurement with other nuclei, e.g., 23Na, 39K (rather than 1H), for which signal sensitivities are not sufficient with a 'low-field bench-top' NMR magnet. The significance of this 2-phase program is that it would lead to a new type of persistent-mode, high-resolution 'microcoil' NMR magnets, in which compactness, simple manufacturability, and ease of operation are the magnet's key features. <P> The three features are vital for a widespread use in pharmaceutical and food industries for discovery and development of drugs and foods; even potentially, perhaps in ~15 years, by medical doctors as a new in-office tool for efficient medical care of patients. We expect the annulus magnet to be cost-effective, and combined with its compactness, it should become a new technology that the NMR magnet industry will in time unquestionably embrace: this, we believe, is the ultimate significance of this new annulus magnet technology. The proposed system has been described to the ultimate users, including those at Novartis and Pfizer; their responses have been highly positive.