Connection termination for a superconductive cable

Abstract

A termination for connecting one end of a superconductive cable ( 10 ), wherein the end of the superconductor is made up of at least one resistively-conductive central support ( 12 ) of substantially cylindrical shape and disposed around the support, and wherein an insulating sheath ( 18 ) surrounds the superconductor. The end of the cable is stripped in order to reveal the central support ( 12 ) and the superconductor ( 14,16 ), and the termination has a metal sleeve ( 30 ) made up of two portions adjacent in succession, wherein a first portion ( 32 ) is engaged around the stripped portion of the central support, and a second portion ( 34 ) is soldered around the stripped portion of the superconductor.

1. A termination for connecting one end of a superconductive cable to a conventional electrical conductor that is not superconductive, said end being made up of at least one resistively-conductive central support of substantially cylindrical shape, of a superconductor disposed around the support, and of an insulating sheath surrounding the superconductor, this end of the cable being stripped to reveal the superconductor, and a length of the stripped superconductor being removed so as to reveal the central support, said termination comprising:
 a metal sleeve made up of two successive portions that are adjacent end to end, 
 a first portion being engaged around the visible portion of the central support; and 
 a second portion being soldered around the visible portion of the superconductor. 
 
     
     
       2. A termination according to  claim 1 , wherein the second portion of the sleeve includes an orifice enabling a solder material to be introduced into the space situated between the stripped portion of the superconductor and the inside wall of the second portion of the sleeve. 
     
     
       3. A termination according to  claim 2 , wherein the solder material has a relatively low melting point, less than 100° C. 
     
     
       4. A termination according to  claim 3 , wherein the solder material is an Sn—Bi—Pb alloy. 
     
     
       5. A termination according to  claim 1 , wherein the second portion of the sleeve includes electrical contact means on the outside surface of the sleeve. 
     
     
       6. A termination according to  claim 5 , wherein the electrical contact means are constituted by grooves of annular shape for receiving metal contact strips. 
     
     
       7. A termination according to  claim 1 , wherein the first portion of the sleeve comprises first and second elements of substantially cylindrical shape, the diameter of the second element being greater than the diameter of the first element, together with an intermediate portion of frustoconical shape situated between the first and second elements, the diameter of the large base of the frustoconical portion being substantially equal to the diameter of the second element, and the diameter of the small base of the frustoconical portion being substantially equal to the diameter of the first element, which first element is engaged around the stripped portion of the central support. 
     
     
       8. A termination according to  claim 1 , wherein the sleeve is made of copper. 
     
     
       9. A termination according to  claim 8 , wherein the sleeve is made of silver-plated copper. 
     
     
       10. A termination according to  claim 1 , wherein the superconductor is constituted by at least one layer of a superconductive tape wound around the central support. 
     
     
       11. A metal sleeve for making a connection to an end of a superconductive cable, the sleeve comprising:
 a portion substantially in the form of a hollow cylinder, wherein said portion includes an orifice enabling a solder material to be introduced into the space situated between a stripped portion of said superconductive cable on which the sleeve is to be engaged and an inside wall of said portion of the sleeve.   
     
     
       12. A sleeve according to claim 11, wherein said portion of the sleeve includes electrical contact means on its outside surface. 
     
     
       13. A sleeve according to claim 12, the electrical contact means are constituted by grooves of annular shape for receiving metal contact strips. 
     
     
       14. A sleeve according to claim 11, wherein said orifice is oblong in shape with a longitudinal axis parallel to the longitudinal axis of the sleeve. 
     
     
       15. A sleeve according to claim 11, wherein said sleeve is made of copper. 
     
     
       16. A sleeve according to claim 11, wherein said sleeve is silver-plated. 
     
     
       17. A termination for connecting one end of a superconductive cable by means of a sleeve according to claim 11, to a conventional electrical conductor that is not superconductive,
 said end of a superconductive cable is made up of   at least one resistively-conductive central support of substantially cylindrical shape,   a superconductor disposed around the support, and   an insulating sheath surrounding the superconductor, this end of the cable being stripped to reveal the superconductor, and   a length of the stripped superconductor is removed so as to reveal the central support,   wherein said termination has   a metal sleeve made up of two successive portions that are adjacent end to end,   a first portion being engaged around the visible portion of the central support, and   said portion, called second portion, is soldered around the visible portion of the superconductor.   
     
     
       18. A termination according to claim 17, wherein the solder material has a relatively low melting point, less than 100° C. 
     
     
       19. A termination according to claim 18, wherein the solder material is an Sn—Bi—Pb alloy. 
     
     
       20. A termination according to claim 17, wherein the first portion of the sleeve has first and second elements of substantially cylindrical shape, the diameter of the second element is greater than the diameter of the first element, together with an intermediate portion of frustoconical shape situated between the first and second elements, the diameter of the large base of the frustoconical portion is substantially equal to the diameter of the second element, and the diameter of the small base of the frustoconical portion is substantially equal to the diameter of the first element, which first element is engaged around the stripped portion of the central support. 
     
     
       21. A termination according to claim 17, wherein the superconductor is constituted by at least one layer of a superconductive tape wound around the central support.