Method of manufacturing a solenoidal magnet structure

1. A method of manufacturing a solenoidal magnet structure, comprising the steps of:

providing a preformed tubular mechanical support structure;

providing a collapsible mold in which to wind coils;

winding wire into defined positions in the mold to form the coils;

placing the preformed tubular mechanical support structure over the coils so wound, wherein the preformed tubular mechanical support structure has an inner diameter greater than an outer diameter of some of the coils;

impregnating the coils and bonding the coils to the mechanical support structure by applying a thermosetting resin and allowing the thermosetting resin to harden; and

collapsing the mold and removing the resultant solenoidal magnet structure comprising the resin impregnated coils and the mechanical support structure from the mold as a single solid piece,

wherein the preformed tubular mechanical support structure carries an axial split and the step of placing the tubular mechanical support structure over the coils comprises passing the mechanical support structure over the coils with the split open, then at least partially closing the split to reduce the internal diameter of the tubular mechanical support structure, to more closely approximate the outer diameter of the coils.

2. The method according to claim 1 , wherein the internal diameter of the tubular mechanical support structure is reduced such that the tubular mechanical support structure grips the outer diameter of the coils.

3. The method according to claim 1 , wherein the mold comprises a collapsible mandrel having at least one removable section, allowing the mold to be disassembled and removed from the interior of the solenoidal magnet structure.

4. The method according to claim 1 , wherein cavities are provided in the mold for retaining electrical leads and other service components.

5. The method according to claim 1 , wherein the defined positions are recesses in the surface of the mold.

6. The method according to claim 1 , wherein the wire is a superconducting wire.

7. The method according to claim 1 , wherein a mold outer is placed over the coils and the mechanical support structure to form an enclosed mold cavity, which is filled with thermosetting resin during the impregnating step.

8. The method according to claim 1 , wherein the impregnating step is performed in a vacuum.

9. The method according to claim 1 , wherein the mold is provided with a lining for aiding the release of the solenoidal magnet structure from the mold.

10. The method according to claim 1 , wherein the impregnation step is performed by a wet lay-up process, wherein the thermosetting resin is applied as a coating on the wire, and on the mechanical support structure, either as a coating on the mechanical support structure or as an impregnated cloth or similar material.

11. The method according to claim 1 , wherein the tubular mechanical support structure consists predominantly of a metal.

12. The method according to claim 1 , wherein the tubular mechanical support structure consists predominantly of a composite material.

13. The method according to claim 1 , wherein some coils are of different outer diameter from others, and differences in the outer diameters of the coils are compensated by use of a filler layer positioned between a radially outer surface of the coil and the radially inner surface of the tubular mechanical support structure.

14. The method according to claim 13 wherein the filler layer comprises a layer of resin-impregnated cloth.

15. The method according to claim 14 wherein the resin-impregnated cloth is added while the coils are in the mold, being added either as resin-impregnated cloth or dry cloth to be impregnated while in the mold.

16. A method of manufacturing a solenoidal magnet structure, comprising the steps of:

providing a collapsible mold in which to wind coils;

winding wire into defined positions in the mold to form the coils;

placing a preformed tubular mechanical support structure over the coils so wound, wherein the preformed tubular mechanical support structure has an inner diameter greater than an outer diameter of some of the coils;

impregnating the coils and bonding the coils to the mechanical support structure by applying a thermosetting resin and allowing the thermosetting resin to harden; and

collapsing the mold and removing the resultant solenoidal magnet structure comprising the resin impregnated coils and the mechanical support structure from the mold as a single solid piece, wherein the support structure is preformed by assembly of a plurality of sections, each of arcuate radial cross-section,

wherein axially inner coils are of different outer diameter from axially outer coils, and separate mechanical support structures are provided for the axially inner coils and the axially outer coils.

17. The method according to claim 16 , wherein an axially inner mechanical support structure supports axially inner coils, and axially outer mechanical support structures support the axially outer coils, the axially inner and axially outer support structures being assembled together prior to the impregnation step.

18. The method according to claim 16 , wherein a first mechanical support structure, of a first internal diameter, supports axially inner coils, and a second mechanical support structure, of a second internal diameter greater than the first internal diameter, supports the axially outer coils,

the first and second mechanical support structures being assembled together prior to the impregnation step.

19. The method according to claim 16 , wherein the mold comprises a collapsible mandrel having at least one removable section, allowing the mold to be disassembled and removed from the interior of the solenoidal magnet structure.

20. The method according to claim 16 , wherein cavities are provided in the mold for retaining electrical leads and other service components.

21. The method according to claim 16 , wherein the defined positions are recesses in the surface of the mold.

22. The method according to claim 16 , wherein the wire is a superconducting wire.

23. The method according to claim 16 , wherein a mold outer is placed over the coils and the mechanical support structure to form an enclosed mold cavity, which is filled with thermosetting resin during the impregnating step.

24. The method according to claim 16 , wherein the impregnating step is performed in a vacuum.

25. The method according to claim 16 , wherein the mold is provided with a lining for aiding the release of the solenoidal magnet structure from the mold.

26. The method according to claim 16 , wherein the impregnation step is performed by a wet lay-up process, wherein the thermosetting resin is applied as a coating on the wire, and on the mechanical support structure, either as a coating on the mechanical support structure or as an impregnated cloth or similar material.

27. The method according to claim 16 , wherein some coils are of different outer diameter from others, and differences in the outer diameters of the coils are compensated by use of a filler layer positioned between a radially outer surface of the coil and the radially inner surface of the tubular mechanical support structure, wherein the filler layer comprises a layer of resin-impregnated cloth, wherein the resin-impregnated cloth is added while the coils are in the mold, being added either as resin-impregnated cloth or dry cloth to be impregnated while in the mold.

28. A method of manufacturing a solenoidal magnet structure, comprising the steps of:

providing a preformed tubular mechanical support structure;

providing a collapsible mold in which to wind coils;

winding wire into defined positions in the mold to form the coils;

placing the preformed tubular mechanical support structure over the coils so wound, wherein the preformed tubular mechanical support structure has an inner diameter greater than an outer diameter of some of the coils;

impregnating the coils and bonding the coils to the mechanical support structure by applying a thermosetting resin and allowing the thermosetting resin to harden; and

collapsing the mold and removing the resultant solenoidal magnet structure comprising the resin impregnated coils and the mechanical support structure from the mold as a single solid piece,

wherein axially inner coils are of different outer diameter from axially outer coils, and separate mechanical support structures are provided for the axially inner coils and the axially outer coils.

29. The method according to claim 28 , wherein an axially inner mechanical support structure supports axially inner coils, and axially outer mechanical support structures support the axially outer coils, the axially inner and axially outer support structures being assembled together prior to the impregnation step.

30. The method according to claim 28 , wherein a first mechanical support structure, of a first internal diameter, supports axially inner coils, and a second mechanical support structure, of a second internal diameter greater than the first internal diameter, supports the axially outer coils,

the first and second mechanical support structures being assembled together prior to the impregnation step.