Magnetic field regenerator

• US 9,622,335 B2
• Filed: 09/27/2013
• Issued: 04/11/2017
• Est. Priority Date: 09/28/2012
• Status: Active Grant

• Current Assignee: Mevion Medical Systems Incorporated
• Original Assignee: Mevion Medical Systems Incorporated
• Inventors: Van Der Laan, Jan, Gall, Kenneth P., Zwart, Gerrit Townsend, Franzen, Ken Yoshiki
• Primary Examiner(s): Owens, Douglas W
• Assistant Examiner(s): Sathiraju, Srinivas
• Application Number:
  US14/039,652
• Publication Number:
  US 20140094640A1
• Time in Patent Office: 1,292 Days
• Field of Search: 315500, 315502, 315505
• CPC Class Codes: A61N 2005/1087 Ions; Protons
• CPC Class Codes: A61N 5/1077 Beam delivery systems
• CPC Class Codes: H05H 13/02 Synchrocyclotrons, i.e. frequency modulated cyclotrons
• CPC Class Codes: H05H 2007/025 Radiofrequency systems
• CPC Class Codes: H05H 2007/046 for beam deflection
• CPC Class Codes: H05H 7/02 Circuits or systems for supplying or feeding radio-frequency energy radio-frequency generators H03B
• CPC Class Codes: H05H 7/04 Magnet systems , e.g. undulators, wigglers free-electron laser H01S3/0903; Energisation thereof
• CPC Class Codes: H05H 7/10 Arrangements for ejecting particles from orbits

Abstract

An example particle accelerator includes the following: a voltage source to provide a radio frequency (RF) voltage to a cavity to accelerate particles from a plasma column, where the cavity has a magnetic field causing particles accelerated from the plasma column to move orbitally within the cavity; an extraction channel to receive the particles accelerated from the plasma column and to output the received particles from the cavity; and a regenerator to provide a magnetic field bump within the cavity to thereby change successive orbits of the particles accelerated from the plasma column so that, eventually, particles output to the extraction channel. The magnetic field is at least 6 Tesla and the magnetic field bump is at most 2 Tesla.

Claims

1. A particle accelerator comprising:

a voltage source to provide a radio frequency (RF) voltage to a cavity to accelerate particles from a plasma column, the cavity having a magnetic field causing particles accelerated from the plasma column to move orbitally within the cavity;

an extraction channel to receive the particles accelerated from the plasma column and to output the received particles from the cavity; and

a regenerator to provide a magnetic field bump within the cavity to thereby change successive orbits of the particles accelerated from the plasma column so that, eventually, particles output to the extraction channel, the regenerator comprising at least one edge comprising a non-orthogonal intersection of two faces;

wherein the magnetic field is at least 6 Tesla and the magnetic field bump is at most 2 Tesla.

2. The particle accelerator of claim 1, wherein the regenerator comprises a ferromagnetic arrangement located at a radial location from the plasma column.

3. The particle accelerator of claim 2, wherein the regenerator comprises a single ferromagnetic arrangement.

4. The particle accelerator of claim 2, wherein the ferromagnetic structure includes steel.

6. The particle accelerator of claim 1, wherein the regenerator has an irregular shape that is designed to produce a magnetic field bump having a specific shape and/or magnitude.

7. The particle accelerator of claim 6, wherein the irregular shape comprises an edge comprising a non-orthogonal intersection of two faces.

9. A proton therapy system comprising:

the particle accelerator of claim 1; and

a gantry on which the particle accelerator is mounted, the gantry being rotatable relative to a patient position;

wherein protons are output from the particle accelerator to the patient position.

10. The proton therapy system of claim 9, wherein the particle accelerator comprises a synchrocyclotron.

30. The particle accelerator of claim 1, wherein the at least one edge comprises two edges, each of the two edges comprising a non-orthogonal intersection of two faces.

45. The particle accelerator of claim 1, wherein the at least one edge comprises a first edge comprised of a non-orthogonal intersection of a first face and a second face, and a second edge comprised of a non-orthogonal intersection of the second face and a third face.

5. A particle accelerator comprising:

a voltage source to provide a radio frequency (RF) voltage to a cavity to accelerate particles from a plasma column, the cavity having a magnetic field causing particles accelerated from the plasma column to move orbitally within the cavity;

an extraction channel to receive the particles accelerated from the plasma column and to output the received particles from the cavity; and

a regenerator to provide a magnetic field bump within the cavity to thereby change successive orbits of the particles accelerated from the plasma column so that, eventually, particles output to the extraction channel;

wherein the magnetic field is at least 4 Tesla and the magnetic field bump is at most 2 Tesla; and

wherein the extraction channel comprises a septum that separates particles entering the extraction channel from other particles in the cavity, the regenerator being configured so that a pitch and an angle of a particle orbit enable a majority of particles in the particle orbit to pass over the septum and into the extraction channel.

8. The particle accelerator of claim 5, wherein particle orbits passing over the septum comprise a range of radii of particles relative to the plasma column.

11. A particle accelerator comprising:

a particle source to provide pulses of ionized plasma to a cavity, a magnetic field being in the cavity;

a voltage source to provide a radio frequency (RF) voltage to the cavity to accelerate particles from the particle source outwardly, the particles accelerated from the particle source traveling in orbits within the cavity;

an extraction channel to receive orbits of particles from the cavity for output from the particle accelerator; and

a regenerator to provide a magnetic field bump within the cavity to shape the orbits of the particles in order to direct the orbits of particles to the extraction channel, the regenerator comprising at least one edge comprising a non-orthogonal intersection of two faces, wherein the magnetic field in the cavity is at least 4 Tesla.

12. The particle accelerator of claim 11, wherein the magnetic field in the cavity is at least 6 Tesla.

13. The particle accelerator of claim 11, wherein the magnetic field bump is at most 2 Tesla.

14. The particle accelerator of claim 11, wherein the regenerator is movable in one or more dimensions relative to the particle source.

15. The particle accelerator of claim 11, wherein the regenerator has a cross-sectional shape that is designed to produce a magnetic field bump have a specific shape and/or magnitude.

16. The particle accelerator of claim 11, wherein the extraction channel comprises a septum that separates particles entering the extraction channel from other particles in the cavity, the regenerator being configured so that a pitch and an angle of a particle orbit enable a majority of particles in the particle orbit to pass over the septum and into the extraction channel.

17. The particle accelerator of claim 16, wherein particle orbits passing over the septum comprise a range of radii of particles relative to the particle source.

18. A proton therapy system comprising:

the particle accelerator of claim 11; and

a gantry on which the particle accelerator is mounted, the gantry being rotatable relative to a patient position;

wherein protons are output from the particle accelerator to the patient position.

19. The proton therapy system of claim 18, wherein the particle accelerator comprises a synchrocyclotron.

31. The particle accelerator of claim 11, wherein the at least one edge comprises two edges, each of the two edges comprising a non-orthogonal intersection of two faces.

46. The particle accelerator of claim 11, wherein the at least one edge comprises a first edge comprised of a non-orthogonal intersection of a first face and a second face, and a second edge comprised of a non-orthogonal intersection of the second face and a third face.

20. A particle accelerator comprising:

a voltage source to provide a radio frequency (RF) voltage to a cavity to accelerate particles from a plasma column, the cavity having a magnetic field causing particles accelerated from the plasma column to move orbitally within the cavity;

an extraction channel to receive the particles accelerated from the plasma column and to output the received particles from the cavity; and

a regenerator to provide a magnetic field bump within the cavity to thereby change successive orbits of the particles accelerated from the plasma column so that, eventually, particles output to the extraction channel;

wherein the particle accelerator is configured to vary an energy of the particles that are output by the particle accelerator, wherein the regenerator comprises at least one edge comprising a non-orthogonal intersection of two faces, and wherein the magnetic field in the cavity is at least 6 Tesla and the magnetic field bump is at most 2 Tesla.

21. The particle accelerator of claim 20, wherein the regenerator is movable in one or more dimensions within the cavity, movement of the regenerator being correlated to an energy of the particles.

22. The particle accelerator of claim 20, further comprising:

coils to pass current to generate the magnetic field, wherein a variation in the amount of current through the coils corresponds to a variation in the energy of the particles.

23. The particle accelerator of claim 20, further comprising:

an energy degrader to affect an energy of a particle beam output from the particle accelerator.

24. A particle accelerator comprising:

a coil to provide a magnetic field to a cavity;

a particle source to provide a plasma column to the cavity;

a voltage source to provide a radio frequency (RF) voltage to the cavity to accelerate particles from the plasma column, the magnetic field causing particles accelerated from the plasma column to move orbitally within the cavity;

an enclosure containing an extraction channel to receive the particles accelerated from the plasma column and to output the particles from the cavity; and

a regenerator to adjust the magnetic field within the cavity to thereby change successive orbits of the particles accelerated from the plasma column so that, eventually, the particles output to the extraction channel, the regenerator being movable within the cavity across orbital locations of the particles.

25. The particle accelerator of claim 24, wherein the regenerator is configured to move radially relative to an approximate center of the cavity.

26. The particle accelerator of claim 25, further comprising:

an actuator to move the regenerator in response to a control signal.

27. The particle accelerator of claim 26, wherein the particle accelerator is rotatable relative to a fixed position;

and

wherein the particle accelerator further comprises a control system to generate the control signal to control movement of the regenerator based on a rotational position of the particle accelerator.

28. The particle accelerator of claim 24, wherein the regenerator comprises a ferromagnetic material.

29. A proton therapy system comprising:

the particle accelerator of claim 24, wherein the particles comprise protons; and

a gantry on which the particle accelerator is mounted, the gantry being rotatable relative to a patient position;

wherein protons are output from the particle accelerator towards the patient position.

32. A particle accelerator comprising:

a voltage source to provide a radio frequency (RF) voltage to a cavity to accelerate particles from a plasma column, the cavity having a magnetic field causing particles accelerated from the plasma column to move orbitally within the cavity;

an extraction channel to receive the particles accelerated from the plasma column and to output the received particles from the cavity; and

a regenerator to provide a magnetic field bump within the cavity to thereby change successive orbits of the particles accelerated from the plasma column so that, eventually, particles output to the extraction channel, the regenerator comprising a face that is not parallel to, or perpendicular to, a mid-plane of the particle accelerator;

wherein the magnetic field is at least 6 Tesla and the magnetic field bump is at most 2 Tesla.

33. The particle accelerator of claim 32, wherein the regenerator comprises a ferromagnetic arrangement located at a radial location from the plasma column.

34. The particle accelerator of claim 33, wherein the regenerator comprises a single ferromagnetic arrangement.

35. The particle accelerator of claim 33, wherein the regenerator has an irregular a cross-sectional shape, the regenerator comprising two edges, each edge comprising a non-orthogonal intersection of two faces.

36. A particle accelerator comprising:

a particle source to provide pulses of ionized plasma to a cavity, a magnetic field being in the cavity;

a voltage source to provide a radio frequency (RF) voltage to the cavity to accelerate particles from the particle source outwardly, the particles accelerated from the particle source traveling in orbits within the cavity;

an extraction channel to receive orbits of particles from the cavity for output from the particle accelerator; and

a regenerator to provide a magnetic field bump within the cavity to shape the orbits of the particles in order to direct the orbits of particles to the extraction channel, the regenerator comprising a face that is not parallel to, or perpendicular to, a mid-plane of the particle accelerator, wherein the magnetic field in the cavity is at least 4 Tesla.

37. The particle accelerator of claim 36, wherein the magnetic field in the cavity is at least 6 Tesla.

38. The particle accelerator of claim 36, wherein the magnetic field bump is at most 2 Tesla.

39. The particle accelerator of claim 36, wherein the regenerator is movable in one or more dimensions relative to the plasma column.

40. The particle accelerator of claim 36, wherein the regenerator has an irregular shape, the regenerator comprising edges including two edges, each of the two edges comprising a non-orthogonal intersection of two faces.

41. The particle accelerator of claim 36, wherein the extraction channel comprises a septum that separates particles entering the extraction channel from other particles in the cavity, the regenerator being configured so that a pitch and an angle of a particle orbit enable a majority of particles in the particle orbit to pass over the septum and into the extraction channel.

42. The particle accelerator of claim 41, wherein particle orbits passing over the septum comprise a range of radii of particles relative to the particle source.

43. A proton therapy system comprising:

the particle accelerator of claim 36; and

a gantry on which the particle accelerator is mounted, the gantry being rotatable relative to a patient position;

wherein protons are output from the particle accelerator to the patient position.

44. The proton therapy system of claim 43, wherein the particle accelerator comprises a synchrocyclotron.