High-Tc SQUID systems for practical use

Planar thin film DC-SQUID gradiometers with small base length (4...6 mm) were optimized for application in different measurement systems. The field gradient noise of these planar DC-SQUID gradiometers in unshielded environment is better than 5 pT/cm/spl radic/(Hz) (at 1 Hz, 77 K). Other components of these systems like electronics, cryostats, scanning equipment, and data analysis software are discussed. An industrial system for nondestructive evaluation and a clinical system for bedside investigations on cardiac infarction are demonstrated as examples of starting cooperation between university and small companies interested in application of superconductivity.