B.N. Samoilov

Force-cooled superconducting systems

Abstract Force-cooled superconducting systems (f c s s) are compared with traditional ‘pool’ systems. A model is proposed to determine the stability criteria for current in f c s s and some results of the analysis of this model are presented. A force-cooled superconducting coil and the apparatus to test the coil, built in IV Kurchatov Atomic Energy Institute during 1968, are described. The results of the tests on the coil are also presented.

Stable optimized superconducting skit coils

Abstract A superconducting system with a field strength of about 50 kOe in a 20 cm bore is described. The system, with a total weight of 260 kg, consists of two coils divided into radial and axial sections; the axial gap between coils can be changed. The winding is made of stabilized copper strip into which wires of Nb-50%Zr alloy are inserted. In order to minimize the total weight as well as the weight of superconductor the winding is self consistent in regard to critical current and to stability. The number of wires ranges from 20 to 4 and the cross section of the strip from 6.5 to 4 mm 2 respectively. In preliminary tests a field of 47 kOe was achieved at a stable current of 575 A (without superconducting-to-normal transition).