Mechanical superconducting switch

1. A mechanically operating superconducting switch comprising:

first and second superconducting wires;

first and second blocks each of superconducting material;

an end of said first superconducting wire being cast in said first block of superconducting material and an end of said second superconducting wire being cast in said second block of superconducting material;

each of said first and second blocks comprising a contact surface and the respective contact surfaces of said first and second blocks comprising complementary protrusions and recesses; and

a mechanical rotary actuator connected to one of said first and second blocks, that closes said switch by rotating said one of said first and second blocks in a first rotary direction in order to drive the respective complementary protrusions and recesses of the respective contact surfaces into physical contact with each other, and that thereafter opens said switch by rotating said one of said first and second blocks in a second rotary direction, opposite to said first rotary direction, in order to separate the respective complementary protrusions and recesses of the respective contact surfaces.

2. A mechanically operating superconducting switch according to claim 1 wherein the first and second superconducting wires are, respectively, ends of coils forming a superconducting magnet.

3. A mechanically operating superconducting switch according to claim 1 , wherein at least one of the first or second blocks is formed of superconducting material in which the corresponding first or second superconducting wire is embedded, the superconducting material of the at least one of the first or second blocks having a ductility greater than a ductility of superconducting material of the first or second superconducting wire embedded therein.

4. A mechanically operating superconducting switch according to claim 1 , comprising a source of electronic control signals that control opening and closing of the switch.

5. A mechanically operating superconducting switch according to claim 1 , wherein:

said first block has an essentially cylindrical wall with an essentially cylindrical cavity contained therein, with the protrusions of said first block being on a wall of the cavity;

said second block has an essentially cylindrical wall, with the protrusions of said second block being on the cylindrical wall of the second block;

the second block is at least partially located within the cavity of the first block, such that the protrusions of the first and second blocks overlap in a circumferential direction; and

said rotary actuator rotates said one block of said first block and said second block with respect to the other around an axis aligned with axes of cylindrical walls of the first and second blocks.

6. A mechanically operating superconducting switch according to claim 5 , wherein the first block has a number of first protrusions equal to the number of protrusions on the second block.

7. A mechanically operating superconducting switch according to claim 5 , wherein at least some faces of the protrusions of one or both of the first block and the second block are covered with an electrically isolating layer.

8. A mechanically operating superconducting switch according to claim 5 , wherein the protrusions of the first and second blocks are parallel to said axis.

9. A mechanically operating superconducting switch according to claim 5 , wherein the protrusions of the first and second blocks are formed as complementary thread surfaces of a helical or conical screw.

10. A mechanically operating superconducting switch according to claim 9 , wherein the thread surfaces are segmented.

11. A mechanically operating superconducting switch according to claim 1 , comprising a vacuum or inert atmosphere around the first and second blocks.

12. A mechanically operating superconducting switch according claim 1 , comprising arrangements for additional mechanical vibration actuation of the first and second blocks.

13. A superconducting magnet structure comprising:

a mechanically operating superconducting switch;

a plurality of coils of superconducting wire electrically connected in series, housed within a cryostat arranged to cool the coils, and wherein first and second superconducting wires from respective electrical ends of the coils are connected to said mechanically operating superconducting switch; and

said mechanically operating superconducting switch comprising first and second blocks of superconducting material with an end of said first wire cast in said first block and an end of said second wire cast in said second block, each of said first and second blocks comprising a contact surface and the respective contact surfaces of said first and second blocks comprising complementary protrusions and recesses, and a mechanical rotary actuator connected to one of said first and second blocks that closes said switch by rotating said one of said first and second blocks in a first rotary direction in order to drive the respective complementary protrusions and recesses of the respective contact surfaces into physical contact with each other, and that thereafter opens said switch by rotating said one of said first and second blocks in a second rotary direction, opposite to said first rotary direction in order to separate the respective complementary protrusions and recesses of the respective contact surfaces.

14. A superconducting magnet structure according to claim 13 wherein the switch is within the cryostat, and comprising a source of electronic control signals that control opening and closing of the switch, said source of electronic control signals being outside the cryostat.

15. A superconducting magnet structure according to claim 13 wherein the mechanical superconducting switch is cooled by a same cooling arrangement used to cool the magnet.