Niobium-tin superconducting coil

• US 7,920,040 B2
• Filed: 02/24/2010
• Issued: 04/05/2011
• Est. Priority Date: 01/19/2006
• Status: Active Grant

• Current Assignee: Massachusetts Institute of Technology
• Original Assignee: Massachusetts Institute of Technology
• Inventors: Schultz, Joel Henry, Antaya, Timothy A.
• Primary Examiner(s): Mai; Anh T
• Assistant Examiner(s): BAISA, JOSELITO SASIS
• Application Number:
  US12/711,627
• Publication Number:
  US 20100148895A1
• Time in Patent Office: 405 Days
• Field of Search: 335/216, 336/180, 336/185, 336/199, 336/208, 505/806, 505/924, 428/662, 428/674, 428/930
• US Class Current: 336/185
• CPC Class Codes: H05H 13/00 Magnetic resonance accelerators; Cyclotrons strophotrons, turbine tubes H01J25/62
• CPC Class Codes: H05H 13/02 Synchrocyclotrons, i.e. frequency modulated cyclotrons
• CPC Class Codes: H05H 7/04 Magnet systems , e.g. undulators, wigglers free-electron laser H01S3/0903; Energisation thereof
• CPC Class Codes: Y10S 505/806 Niobium base, Nb
• CPC Class Codes: Y10S 505/924 Making superconductive magnet or coil
• CPC Class Codes: Y10T 29/49014 Superconductor

Abstract

A Nb₃Sn superconducting coil can be formed from a wire including multiple unreacted strands comprising tin in contact with niobium. The strands are wound into a cable, which is then heated to react the tin and niobium to form a cable comprising reacted Nb₃Sn strands. The cable comprising the reacted Nb3Sn strands are then mounted in and soldered into an electrically conductive channel to form a reacted cable-in-channel of Nb₃Sn strands. The cable-in-channel of reacted Nb3Sn strands are then wound to fabricate a superconducting coil. The Nb₃Sn superconducting coil can be used, for example, in a magnet structure for particle acceleration. In one example, the superconducting coil is used in a high-field superconducting synchrocyclotron.

Claims

1. A superconducting coil, comprising:

a plurality of windings of a coil comprising Nb₃Sn strands, wherein the strands have a niobium content that increases closer to the perimeter of the strands; and

an electrically conductive channel in which the coil comprising Nb₃Sn strands is mounted, with no more than four Nb₃Sn strands mounted in a cross-section of the channel.

2. The superconducting coil of claim 1, further comprising solder in the channel, wherein the solder bonds the coil comprising Nb₃Sn to the channel.

3. The superconducting coil of claim 1, wherein the channel comprises copper.

4. The superconducting coil of claim 1, wherein coil includes at least 1,500 of the windings.

5. The superconducting coil of claim 4, wherein the windings provide a current-carrying capacity of at least 3 million amps-turns in the coil.

6. The superconducting coil of claim 1, further comprising glass fiber inserted between the windings.

7. The superconducting coil of claim 6, further comprising epoxy impregnated into the glass fiber.

8. The superconducting coil of claim 1, wherein the coil is wound in a radius between 14 and 21 inches.

9. The superconducting coil of claim 1, wherein the cross-section of the channel orthogonal to its length has dimensions no greater than about 2.4 mm.

10. The superconducting coil of claim 1, wherein the coil is mounted in a magnetic yoke of a synchrocyclotron.