Stable and permanent niobium point-contact SQUID's have been fabricated by using oxidized niobium screws to form the point contact. The reliability of these devices is further ensured by a simple and versatile environmental shielding procedure. Over a period of five years there have been no failures of such SQUID's in our laboratory. The signal-to-noise performance of these SQUID's is quite good.
No takes yet. Share an insight, caveat, or question.
Buhrman et al. (1974) studied this question.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: