Charged particle beam acceleration and extraction method and apparatus used in conjunction with a charged particle cancer therapy system

• US 8,415,643 B2
• Filed: 11/05/2011
• Issued: 04/09/2013
• Est. Priority Date: 05/22/2008
• Status: Active Grant

• Current Assignee: Andrey Vladimirovich Balakin, Pavel Vladimirovich Balakin
• Original Assignee: Vladimir Balakin
• Inventors: Balakin, Vladimir
• Primary Examiner(s): MASKELL, MICHAEL P
• Application Number:
  US13/290,068
• Publication Number:
  US 20120043472A1
• Time in Patent Office: 521 Days
• Field of Search: 250/396.R, 250/492.1, 250/492.3, 313/62, 315/503, 315/504
• US Class Current: 250/492.1
• CPC Class Codes: A61N 2005/1074 Details of the control system, e.g. user interfaces
• CPC Class Codes: A61N 2005/1087 Ions; Protons
• CPC Class Codes: A61N 5/10 X-ray therapy; Gamma-ray therapy; Particle-irradiation therapy A61N5/01 takes precedence
• CPC Class Codes: H05H 13/04 Synchrotrons
• 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

The invention comprises a charged particle beam acceleration and/or extraction method and apparatus used in conjunction with charged particle beam radiation therapy of cancerous tumors. Novel design features of a synchrotron are described. Particularly, turning magnets, edge focusing magnets, and extraction elements are described that minimize the overall size of the synchrotron, provide a tightly controlled proton beam, directly reduce the size of required magnetic fields, directly reduces required operating power, and allow continual acceleration of protons in a synchrotron even during a process of extracting protons from the synchrotron.

Claims

1. An apparatus for tumor therapy using charged particles, comprising:

a synchrotron, comprising;

a center; and

a charged particle circulation beam path running;

about said center;

through straight sections; and

through turning sections,

wherein at least one of said turning sections comprises a total of at least five bending magnet edge focusing surfaces for a ninety degree turn of the circulation beam path.

2. The apparatus of claim 1, wherein said number of turning sections comprises exactly four turning sections, wherein each of said four turning sections turns the charged particle circulation beam path about ninety degrees, said synchrotron capable of accelerating the charged particles to at least 300 MeV.

3. The apparatus of claim 2, wherein said four turning sections comprise at least thirty-two charged particle edge focusing surfaces.

4. The apparatus of claim 1, wherein said charged particle circulation beam path does not pass through any operational quadrupole magnets.

5. The apparatus of claim 1, each of said bending magnets comprising:

a gap, said charged particle beam path running through said gap, and

a core, wherein said core terminates at said gap with a surface comprising a finish of less than about ten microns polish.

6. The apparatus of claim 1, wherein said synchrotron further comprises:

an extraction material;

at least a one kilovolt direct current field applied across a pair of extraction blades; and

a deflector,

wherein during use the charged particles pass through said extraction material resulting in a reduced energy charged particle beam,

wherein during use the reduced energy charged particle beam passes between said pair of extraction blades, and

the direct current field configured to redirect the reduced energy charged particle beam through said deflector to yield an extracted charged particle beam.

7. The apparatus of claim 6, wherein said extraction material comprises at least one foil of thirty to one hundred micrometers thickness,

wherein said extraction material comprises atoms consisting essentially of six or fewer protons per atom.

8. The apparatus of claim 6, further comprising a pair of betatron oscillation inducing blades, wherein the charged particles traverse said pair of betatron oscillation inducing blades during acceleration.

9. The apparatus of claim 8, wherein a radio frequency voltage applied across said pair of betatron oscillation inducing blades induces a betatron oscillation on the circulating charged particles,

wherein the charged particles comprise a radius of curvature passing through said betatron oscillation blades,

wherein the reduced energy charged particle beam, resulting from transmission through said extraction material, comprises a radius of curvature passing through said extraction blades, and

wherein a first distance between said center of said synchrotron and said pair of extraction blades is less than a second distance between said center of said synchrotron and said pair of betatron oscillation inducing blades.

10. The apparatus of claim 1, further comprising:

a first focusing edge;

a second focusing edge;

a third focusing edge; and

a fourth focusing edge,

wherein said at least four bending magnets reside in a first of said turning sections,

wherein said at least four bending magnets comprise;

a first bending magnet and a second bending magnet,

wherein said first bending magnet terminates on opposite sides with said first focusing edge and said second focusing edge,

wherein a first plane established by said first focusing edge intersects a plane established by said second focusing edge beyond said center of said synchrotron,

wherein said second bending magnet terminates on opposite sides with said third focusing edge and said fourth focusing edge,

wherein a second plane established by said third focusing edge intersects a plane established by said fourth focusing edge beyond said center of said synchrotron,

all of said first focusing edge;

said second focusing edge;

said third focusing edge; and

said fourth focusing edge configured to bend movement of the charged particles toward said center of said synchrotron.

11. The apparatus of claim 1, further comprising:

a winding coil, wherein a turn in said coil wraps around at least two of said turning magnets, wherein said turn does not occupy space directly between said at least two of said turning magnets.

12. A method for tumor therapy using charged particles, comprising the step of:

accelerating the charged particles in a charged particle circulation beam path running about a center of a synchrotron, said charged particle circulation beam path comprising;

straight sections; and

turning sections,

wherein at least one of said turning sections comprises at least five bending magnet edge focusing surfaces per a ninety degree turn of the circulation beam path.

13. The method of claim 12, further comprising the steps of:

accelerating the charged particles to at least 300 MeV using said synchrotron, wherein said number of turning sections comprises exactly four turning sections; and

turning the charged particles about ninety degrees with each of said four turning sections.

14. The method of claim 13, wherein said four turning sections comprise at least thirty-two charged particle edge focusing surfaces.

15. The method of claim 12, wherein said turning sections comprise at least ten bending magnets.

16. The method of claim 12, further comprising the step of:

running the charged particles through a gap, said gap running through each of said bending magnets, said gap comprising a surface finish of less than about ten microns polish, wherein each of said turning magnets comprises a core terminating at said gap.

17. The method of claim 12, further comprising the steps of:

transmitting the charged particles through an extraction material, said extraction material yielding a reduced energy charged particle beam;

applying at least five hundred volts across a first pair of blades; and

passing the reduced energy charged particle beam between said first pair of blades,

wherein said first pair of blades redirect the reduced energy charged particle beam to a deflector,

wherein said deflector yields an extracted charged particle beam.

18. The method of claim 17, wherein said extraction material comprises a foil of about forty to sixty microns thickness,

wherein said extraction material comprises any of:

beryllium;

lithium hydride; and

carbon.

19. The method of claim 12, further comprising the steps of:

transmitting the charged particles through an extraction material in said charged particle beam path, said extraction material yielding a reduced energy charged particle beam;

applying a field of at least five hundred volts across a pair of extraction blades, said charged particle beam path passing between said pair of extraction blades;

passing the reduced energy charged particle beam between said pair of extraction blades; and

prior to said step of transmitting, inducing betatron oscillation on the circulating charged particle beam,

wherein said field redirects the reduced energy charged particle as an extracted charged particle beam,

wherein said step of inducing occurs at a selected energy level of the circulating charged particle beam,

wherein the betatron oscillation increases average radius of curvature of the circulating charged particle beam until said step of transmitting yields the reduced energy charged particle beam,

wherein said step of inducing at said selected energy level yields an energy controlled extracted charged particle beam.

20. The method of claim 12, further comprising the step of:

bending the charged particles toward said center of said synchrotron using all of a first focusing edge, a second focusing edge, a third focusing edge, and a fourth focusing edge,

wherein said at least four bending magnets are located in a first of said turning sections,

wherein said at least four bending magnets comprise;

a first bending magnet and a second bending magnet,

wherein said first bending magnet terminates on opposite sides with said first focusing edge and said second focusing edge,

wherein a first plane established by said first focusing edge intersects a plane established by said second focusing edge beyond said center of said synchrotron,

wherein said second bending magnet terminates on opposite sides with said third focusing edge and said fourth focusing edge, and wherein a second plane established by said third focusing edge intersects a plane established by said fourth focusing edge beyond said center of said synchrotron.