Claims
- 1. A superconducting magnet comprising:
- (a) a coil of turns of conductor including at least a supercondcting composite material, the turns of conductor lying substantially on a surface which defines a frustum of a cone having a wide end and a narrow end, such that the outward pressure as a result of current flowing through the conductor in the magnetic field produced by the magnet at the wide end of the coil is less than the outward pressure at the narrow end of the coil; and
- (b) means for supporting the coil of conductors in the magnet to carry the outward pressure imposed on the coil by the interaction of the current flowing in the conductor with the magnetic field, wherein the turns of the conductor in the coil have outwardly bowed ripples therein and inner portions between the ripples with the ripple pattern extending around the circumferential periphery of the magnet structure, and wherein the means for supporting includes support struts extending from a surrounding support mass to engage the conductor at the inwardly bowed portions of the rippled conductor forming the coil.
- 2. The superconducting magnet of claim 1 wherein the angle of the conical surface with respect to its central axis is selected such that the outward pressure at the widest end of the coil is substantially zero.
- 3. The superconducting magnet of claim 2 wherein the aspect ratio is equal to the height of the coil divided by its diameter is approximately 0.03 and the angle of the conical surface with respect to the central axis is approximately 3.degree. .
- 4. The magnet structure of claim 1 further comprising a second, inner coil of turns of conductor including at least a superconducting composite material, the second coil disposed adjacent to the first coil with each turn of the second coil at substantially the same level as a turn on the first coil, and including an inner support structure between the first and second coils and engaged to the conductors of each of the coils.
- 5. The superconducting magnet of claim 1 wherein each of the ripples in the conductor is formed in a shape which undergoes minimum bending during changes in the level of current flowing through the conductor.
- 6. The superconducting magnet of claim 5 wherein the conductor includes a composite of superconductor and a normal conductor and wherein the normal conductor is high purity aluminum.
- 7. A superconducting magnet comprising:
- (a) a coil of turns of conductor including at least a superconducting composite material, the conductor having outwardly bowed ripples therein and inner portions between the ripples with the ripple pattern extending around a substantially circular circumferential periphery,
- (b) support struts extending from an outer supporting mass to support the coil of ripple conductor at the innermost portions of the ripples of the conductor, and
- wherein the ripples are formed to have a non-circular shape which undergoes minimum bending during changes in the current flowing through the conductor with a magnetic field applied to the conductor, and wherein the ripple shape is calculated iteratively by vector addition using the following expression for the Kth iteration:
- R.sub.K =R.sub.K-1 +.alpha.(.delta.-.delta..sub.S)
- where .delta. is the displacement vector at a position along the ripple, .delta..sub.S is the displacement vector at a strut location, .alpha. is a relaxation factor selected to avoid oscillation in the calculations, and R.sub.K-1 =R.sub.0 for the first iteration where R.sub.0 is a chosen initial ripple shape.
- 8. The superconducting magnet of claim 7 wherein the conductor is a composite conductor formed of a superconductor and a normal conducting high-purity aluminum.
- 9. The superconducting magnet of claim 7 wherein the coil is formed of multiple turns of conductor with the turns of conductor arrayed one above the other, each turn of conductor having ripples therein with a minimum bending ripple shape.
- 10. The superconducting magnet of claim 9 including a second, inner coil of conductor including at least a superconducting composite conductor, the inner coil disposed adjacent to the first coil, the second coil formed of turns of conductor having outwardly bowed ripples therein and inner portions between the ripples with the ripple pattern extending around the circumferential periphery of the magnet and each ripple having a minimum bending ripple shape.
- 11. A superconducting magnet comprising:
- (a) a coil of turns of conductor including at least a superconducting composite material disposed in a trench in the ground with an outer sidewall of the trench surrounding the coil, the turns of conductor lying substantially on a surface which defines a frustum of a cone having a top wide end and a bottom narrow end such that the outward pressure as a result of current flowing through the conductor in the magnetic field produced by the magnet at the top end of the coil is less than the outward pressure at the bottom end of the coil; and
- (b) means for supporting the coil of conductors in the magnet to carry the outward pressure imposed on the coil by the interaction of the current flowing in the conductor with the magnetic field to the outer sidewall, the means including support struts extending from the coil of conductors to the outer sidewall.
- 12. The superconducting magnet of claim 1 wherein the angle of the conical surface with respect to its central axis is selected such that outward pressure at the top end of the coil which is imposed on the sidewall is substantially zero.
- 13. The superconducting magnet of claim 16 wherein the aspect ratio equal to the height of the coil divided by its diameter is approximately 0.03 and the angle of the conical surface with respect to the central axis is approximately 3.degree. .
- 14. The magnet structure of claim 11 further comprising a second, inner coil of turns of conductor including at least a superconducting composite material, the second coil disposed adjacent to the first coil with each turn of the second coil at substantially the same level as a turn on the first coil, and including an inner support structure between the first and second coils and engaged to the conductors of each of the coils.
- 15. The superconducting magnet of claim 11 wherein the turns of the conductor in the coil have outwardly bowed ripples therein and inner portions between the ripples with the ripple pattern extending around the circumferential periphery of the magnet structure.
- 16. The superconducting magnet of claim 15 wherein the support struts extend from the surrounding sidewall to engage the conductor at the inwardly bowed portions of the rippled conductor forming the coil.
- 17. The superconducting magnet of claim 16 wherein each of the ripples in the conductor is formed in a shape which undergoes minimum bending during changes in the level of current flowing through the conductor.
- 18. The superconducting magnet of claim 17 wherein the conductor includes a composite of superconductor and a normal conductor and wherein the normal conductor is high purity aluminum.
- 19. A superconducting magnet comprising:
- (a) a coil of turns of conductor including at least a superconducting composite material, the turns of conductor lying substantially on a surface which defines a frustum of a cone having a wide end and a narrow end such that the outward pressure as a result of current flowing through the conductor in the magnetic field produced by the magnet at the wide end of the coil is less than the outward pressure at the narrow end of the coil, the turns of the conductor in the coil having outwardly bowed ripples therein and inner portions between the ripples with the ripple pattern extending around the circumferential periphery of the magnet structure; and
- (b) support struts extending from a surrounding supporting mass to engage the conductor at the inwardly bowed portions of the rippled conductor forming the coil.
- 20. The superconducting magnet of claim 19 wherein the angle of the conical surface with respect to its central axis is selected such that the outward pressure at the top end of the coil is substantially zero.
- 21. The superconducting magnet of claim 20 wherein the aspect ratio equal to the height of the coil divided by its diameter is approximately 0.03 and the angle of the conical surface with respect to the central axis is approximately 3.degree. .
- 22. The magnet structure of claim 19 further comprising a second, inner coil of turns of conductor including at least a superconducting composite material and formed with ripples therein, the second coil disposed adjacent to the first coil with each turn of the second coil at substantially the same level as a turn on the first coil, and including an inner support structure between the first and second coils and engaged to the conductors of each of the coils.
- 23. The superconducting magnet of claim 19 wherein each of the ripples in the conductor is formed in a shape which undergoes minimum bending during changes in the level of current flowing through the conductor.
- 24. The superconducting magnet of claim 23 wherein the composite conductor includes a superconductor and a normal conductor and wherein the normal conductor is high purity aluminum.
Government Interests
This invention was made with United States government support awarded by the NASA Headquarters (NASA), Grant # NAG-3-1041. The United States Government has certain rights in this invention.
US Referenced Citations (7)
Non-Patent Literature Citations (1)
Entry |
B. Nilsson and Y. M. Eyssa, "Constant Tension Winding in a Single Layer Rippled Soleniods," IEEE Trans. on Magnetics, vol. MAG-19, No. 3, 1983, pp. 354-358. |