Superconducting Joints in Internal Tin NB(TA) 3SN

Our goal is to apply superconducting joints, developed in Phase I, to compact a less expensivehigh field NMR magnets in the (1)H frequency range 750-1000MHz with inner sections constructed froma new internal tin Nb(3)Sn conductor. Advances in NMR application, particularly high resolution solutionNMR and chemical shift micro imaging demand higher fields for increased sensitivity of detection andimproved spectral resolution. In addition, recently devised experiments require larger bores toaccommodate more hardware that might include a combination of gradient coils, variable temperature,and high power RF pulse amongst others. This research is aimed at developing novel superconductingjoints with reduced field dependence in a newly developed Nb(3)Sn superconductor with higher currentdensity than previous materials. The three crucial concurrent specifications of an NMR magnet arereliable magnetic field, uniformity and temporal stability. This research concentrates on the leastunderstood aspects of the stability of an NMR magnet, being superconducting joints between lengthsof superconductor, and their field dependence. If joints with higher tolerance to background field canbe developed, then NMR magnets could be made much shorter than existing NMR magnets.