Conductors for a 1 GHz superconducting magnet

Abstract

A b s Cra c C --The development of a high resolution high-field 1 GHz NMR spectrometer has been undertaken by Battelle Pacific Northwest Laboratories (BPNL). In preparation for the design of the superconducting magnet for that instrument, BPNL sponsored a program to measure the properties at high field (up to 23.5 T) and low temperature (1.8 K) of a number of commercially available superconductors. Lengths of these conductors were obtained and tested as short samples and in small coils. The critical current densities, index values and strain dependence of these properties were characterized. The potential applications of these conductors in construction of a 1 GHz NMR magnet are discussed.

The wonders of magnetism

“…The completion of the 900 MHz NMR spectrometer proved to be a far more complex and challenging task. Although preliminary studies had been performed to characterize the physical properties and operational characteristics of several types of niobium-tin superconducting wire from various manufacturers [Tenforde, 1991;Pourrahimi et al, 1994;Wang et al, 1994], the production of a 21.1 T NMR magnet that could operate in a persistent superconducting mode for extended periods of time proved to be exceptionally difficult and required several costly attempts over a period of nearly one decade. Finally the manufacturer, Oxford Instruments in Oxon, England, succeeded in producing the magnet and a fully functional wide bore (65 mm diameter), 900 MHz NMR spectrometer in 2001.…”