In this work, the development of a superconducting joint between GdBa 2 Cu 3 O 7−x -based secondgeneration high temperature superconducting tapes using a thin YBa 2 Cu 3 O 7−x intermediate layer is presented. The critical current of the superconducting joint was 18 A, which is about 30% of the current in the original tape. The persistent field decay of the one-turn loop showed a joint resistance of less than 6•10 −13 Ω at 77 K.

No abstract

To study heat transfer from a metal surface, the method of "double thickness" is proposed, in which the heating of the central region of a conductor and its average temperature are measured. As a result, the surface temperature is determined directly under stationary cooling. The method was tested to measure the characteristics of the heat transfer from a stainless steel tape to liquid nitrogen.

No abstract

The electrical characteristics of superconducting coils with non-insulated windings are studied. The procedures for measuring the parameters of uninsulated superconducting windings are described. In particular, the inductance is measured by voltage with a linear current input at a given rate. Attention is focused on the impossibility of correctly determining the inductance in a winding with an uninsulated superconductor in a normal state. It is noted that in a superconducting state at currents below the critical value, the inductance of the winding is comparable to the inductance with an insulated wire. The results of measurements of inductance, radial resistance, static current-voltage and magnetic characteristics of two tape coils with non-insulated superconducting windings, one of which had a soldered connection, are presented. Conditions for measuring the parameters of non-insulated superconducting windings are formulated when they are compared with insulated windings.