SUPERCONDUCTING TRANSFORMERS FOR STUDY OF HIGH

A facility for measurement of the critical current and minimal quench energy of Rutherford-type superconducting cables for accelerator magnets is created. The current in the sample is energized by a superconducting transformer circuit, using an inductive method, where the sample conductor is a part of the secondary circuit. Two superconducting transformers have been built; one of them is a solenoid type coil. The transformer consists of two concentric solenoids; the secondary coil is placed inside the primary coil. External magnetic field up to 6.5 T is provided by a superconducting solenoid with the aperture diameter of 60 mm. The second superconducting transformer with racetrack coils has been designed and taken into operation. Short-circuited sample, fixed on a special holder, is placed in the aperture of a superconducting dipole magnet such way that the plane of sample loop is perpendicular to direction of external magnetic field, which can reach up to 6 T. The critical current of the secondary superconducting coil is 18 kA. The equipment for measurements of characteristics of a superconducting cable versus magnetic field is described.