Isochronous cyclotrons employing magnetic field concentrating or guiding sectors

Patent metadata

Field	Value
Publication number	US-11570880-B2
Application number	US-202016838750-A
Country	US
Kind code	B2
Filing date	Apr 2, 2020
Priority date	Apr 2, 2020
Publication date	Jan 31, 2023
Grant date	Jan 31, 2023

Abstract

An isochronous cyclotron including one or more coils and a plurality of pairs of bulk superconductor sectors. The one or more coils can be configured to generate a magnetic field in the beam chamber having a magnetic flux density that increases radially from the central axis of the beam chamber, and is orientated substantially perpendicular to the median acceleration plane of the beam chamber. Each pair of bulk superconductor sectors can be disposed on opposite sides of the median acceleration plane. The plurality of pairs of bulk superconductor sectors can be configured to guide or concentrate the magnetic field to provide an axial focusing component of the magnetic field.

First claim

What is claimed is:

1. An isochronous cyclotron comprising:
a beam chamber including a central axis and a median acceleration plane;
a particle source coupled to the median acceleration plane proximate the central axis of the beam chamber;
one or more coils disposed about the beam chamber;
one or more radio frequency drive circuits coupled to the beam chamber; and
a plurality of pairs of bulk superconductor sectors, wherein each pair of bulk superconductor sectors are disposed on opposite sides of the median acceleration plane and extend from the central axis along a radial length of the median acceleration plane.

2. The isochronous cyclotron according to claim 1 , further comprising:
a plurality of pairs of structural sectors, wherein each pair of structural sectors are disposed on opposite sides of the median acceleration plane; and
wherein the plurality of pairs of bulk superconductor sectors are disposed between adjacent pairs of structural sectors.

3. The isochronous cyclotron according to claim 2 , wherein the plurality of pairs of structural sectors comprise a plurality of pairs of magnetically neutral sectors.

4. The isochronous cyclotron according to claim 2 , wherein the plurality of pairs of structural sectors comprise a plurality of pairs of ferromagnetic, paramagnetic, or diamagnetic sectors.

5. The isochronous cyclotron according to claim 1 , wherein the plurality of pairs of bulk superconductor sectors include a bulk high-temperature superconductor.

6. The isochronous cyclotron according to claim 1 , wherein the plurality of pairs of bulk superconductor sectors include a bulk type-II superconductor.

7. The isochronous cyclotron according to claim 1 , wherein the one or more coils comprise a pair of coils encircling the beam chamber and disposed on opposite sides of the median acceleration plane of the beam chamber.

8. The isochronous cyclotron according to claim 1 , wherein the one or more coils comprise one or more superconductor coils.

9. The isochronous cyclotron according to claim 1 , wherein the plurality of pairs of bulk superconductor sectors have a wedge shape.

10. The isochronous cyclotron according to claim 1 , wherein the plurality of pairs of bulk superconductor sectors have a spiral shape.

11. An isochronous cyclotron comprising:
one or more coils disposed about a beam chamber and configured to generate a magnetic field in the beam chamber having a magnetic flux density that increases radially from a central axis of the beam chamber and is orientated substantially perpendicular to a median acceleration plane; and
a plurality of pairs of bulk superconductor sectors, wherein each pair of bulk superconductor sectors are disposed on opposite sides of a median acceleration plane from the central axis to an outer extent of the median acceleration plane, and wherein the plurality of pairs of bulk superconductor sectors are configured to guide or concentrate the magnetic field to provide an axial focusing component of the magnetic field.

12. The isochronous cyclotron according to claim 11 , further comprising:
a plurality of pairs of structural sectors, wherein each pair of structural sectors are disposed on opposite sides of the median acceleration plane of the beam chamber; and
wherein the plurality of pairs of bulk superconductor sectors are disposed between adjacent pairs of structural sectors, and wherein the plurality of pairs of bulk superconductor sectors are configured to guide or concentrate the magnetic field into the beam chamber proximate the plurality of pairs of structural sectors.

13. The isochronous cyclotron according to claim 12 , wherein the plurality of pairs of structural sectors and the plurality of pairs of bulk superconductor sectors have a form factor configured to increase the axial focusing component of the magnetic field.

14. The isochronous cyclotron according to claim 12 , wherein an axial separation between respective pairs of the bulk superconductor sectors is smaller and or greater than an axial separation between respective pairs of the structural sectors.

15. The isochronous cyclotron according to claim 11 , wherein the plurality of pairs of bulk superconductor sectors include a bulk high-temperature superconductor.

16. The isochronous cyclotron according to claim 11 , wherein the plurality of pairs of bulk superconductor sectors include a bulk type-II superconductor.

17. The isochronous cyclotron according to claim 11 , wherein the plurality of pairs of bulk superconductor sectors are maintained in a mixed state.

18. The isochronous cyclotron according to claim 11 , wherein the one or more coils comprise a pair of coils encircling the beam chamber and disposed on opposite sides of the median acceleration plane of the beam chamber.

19. The isochronous cyclotron according to claim 11 , wherein the one or more coils comprise one or more superconductor coils.

20. A charged particle acceleration method comprising:
providing a plurality of pairs of bulk superconductor sectors, wherein each pair of bulk superconductor sectors are disposed on opposite sides of a median acceleration plane of a beam chamber and extend a radial length of the median acceleration plane, and wherein pairs of the bulk superconductor sectors are spaced apart from each other along a radial arch of the beam chamber; and
providing a magnetic field in the beam chamber having a magnetic flux density that increases radially from a central axis of the beam chamber and is orientated substantially perpendicular to the median acceleration plane, wherein the plurality of pairs of bulk superconductor sectors are configured to guide or concentrate the magnetic field between the plurality of pairs of bulk superconductor sectors to provide an axial focusing component of the magnetic field.

21. The charged particle acceleration method of claim 20 , further comprising:
providing a plurality of pairs of structural sectors, wherein each pair of structural sectors are disposed on opposite sides of the median acceleration plan of the beam chamber and wherein pairs of the bulk superconductor sectors are disposed between adjacent pairs of the structural sectors.

22. The charged particle acceleration method of claim 20 , further comprising:
providing charge particles proximate a central axis of the beam chamber; and
providing a radio frequency signal configured to accelerate the charged particles in the beam chamber in an orbital trajectory expanding outward from the central axis of the beam chamber.

23. The charged particle acceleration method of claim 20 , wherein the plurality of pairs of bulk superconductor sectors include a bulk high-temperature superconductor.

24. The charged particle acceleration method of claim 20 , wherein the plurality of pairs of bulk superconductor sectors include a bulk type-II superconductor.

25. The charged particle acceleration method of claim 20 , wherein the provided magnetic field is above a lower critical magnetic field Hc 1 and below an upper critical magnetic field Hc 2 of a bulk superconductor material of the bulk superconductor sectors.

Assignees

• Varian Medical Systems Particle Therapy Gmbh
• Bock Joachim

Inventors

• Bock Joachim
• Godeke Arno

Classifications

• H05H13/005 Primary

  Cyclotrons · CPC title

• H05H2007/025

  Radiofrequency systems · CPC title

• H05H7/04 Primary

  Magnet systems {, e.g. undulators, wigglers (free-electron laser H01S3/0903)}; Energisation thereof · CPC title

• H05H7/02

  Circuits or systems for supplying or feeding radio-frequency energy · CPC title

• H01F6/06

  Coils, e.g. winding, insulating, terminating or casing arrangements therefor · CPC title