Shielding structures for linear accelerators

Patent metadata

Field	Value
Publication number	US-10143076-B2
Application number	US-201615097007-A
Country	US
Kind code	B2
Filing date	Apr 12, 2016
Priority date	Apr 12, 2016
Publication date	Nov 27, 2018
Grant date	Nov 27, 2018

Abstract

An apparatus includes an accelerator guide and a shielding structure enclosing the accelerator guide. The accelerator guide includes an electron source at a first end, a target at a second end, and a plurality of accelerating cavities coupled in series along a longitudinal axis between the first end and the second end. The accelerator guide has a contour as viewed in the longitudinal axis. The shielding structure has an inner wall surface defining a contour as viewed in the longitudinal axis generally conformal to the contour of the accelerator guide.

First claim

What is claimed is:

1. An apparatus, comprising:
an accelerator guide comprising an electron source at a first end, a target at a second end, and a plurality of accelerating cavities coupled in series along a longitudinal axis between the first end and the second end, the accelerator guide having a contour as viewed in the longitudinal axis;
a shielding structure enclosing at least the electron source and the plurality of accelerating cavities of the accelerator guide, the shielding structure having an inner wall surface defining a contour as viewed in the longitudinal axis generally conformal to the contour of the accelerator guide.

2. The apparatus of claim 1 , wherein the accelerator guide further comprises a guide-slide coupled at the second end, the guide-slide defining the contour of the accelerator guide as viewed in the longitudinal axis and providing a contact surface slidably engaging the inner wall surface of the shielding structure.

3. The apparatus of claim 2 , wherein the guide-slide has a contour generally in an obround shape as view in the longitudinal axis.

4. The apparatus of claim 2 , wherein the shielding structure comprises a mono-block surrounding at least a major portion of the accelerator guide.

5. The apparatus of claim 4 , wherein the mono-block comprises a radiation shield and a magnetic shield integrated with the radiation shield.

6. The apparatus of claim 4 , further comprising a mounting flange coupled to the first end of the accelerator guide for mounting the accelerator guide to the mono-block.

7. The apparatus of claim 6 , wherein the accelerator guide and the shielding structure are movable as a unit during alignment of the accelerator guide.

8. The apparatus of claim 1 , wherein the accelerator guide further comprises a plurality of side cavities each coupling two adjacent accelerating cavities, and wherein the contour of the accelerator guide comprises a first section defined by a portion of an accelerating cavity and a second section defined by two side cavities coupled to the accelerating cavity.

9. An apparatus, comprising:
an accelerator guide comprising an electron source at a first end, a target at a second end, and a plurality of accelerating cavities coupled in series along a longitudinal axis between the first end and the second end; and
a shielding structure enclosing the accelerator guide, wherein the shielding structure comprises a mono-block operable to hold the accelerator guide at least in a horizontal orientation,
wherein the mono-block comprises a cut-away providing clearance for a waveguide coupled to the accelerator guide.

10. The apparatus of claim 9 , wherein the mono-block is configured to surround less than a major portion of the accelerator guide.

11. An apparatus comprising:
an accelerator guide comprising an electron source at a first end, a target at a second end, and a plurality of accelerating cavities coupled in series along a longitudinal axis between the first end and the second end; and
a shielding structure enclosing the accelerator guide, wherein the shielding structure comprises a mono-block operable to hold the accelerator guide at least in a horizontal orientation,
wherein the mono-block is configured to surround at least a major portion of the accelerator guide.

12. The apparatus of claim 11 , wherein the mono-block comprises a radiation shield and a magnetic shield integrated with the radiation shield.

13. The apparatus of claim 11 , wherein the accelerator guide has a contour as viewed in the longitudinal axis and the mono-block has an inner wall surface defining a contour as viewed in the longitudinal axis generally conformal to the contour of the accelerator guide.

14. The apparatus of claim 13 , wherein the contour defined by the inner wall surface of the mono-block is generally in an obround shape.

15. The apparatus of claim 13 , wherein the accelerator guide further comprises a guide-slide at the second end, the guide-slide providing a contact surface slidably engaging the inner wall surface of the mono-block.

16. The apparatus of claim 15 , wherein the guide-slide has a contour generally in an obround shape as view in the longitudinal axis.

17. The apparatus of claim 13 , wherein the mono-block comprises a mounting interface for mounting the accelerating guide to the mono-block.

18. The apparatus of claim 17 , further comprising a mounting flange coupled to the first end of the accelerator guide for securing the accelerator guide to the mono-block via the mounting interface.

19. An apparatus, comprising:
an accelerator guide comprising an electron source at a first end, a target at a second end, and a plurality of accelerating cavities coupled in series along a longitudinal axis between the first end and the second end; and
a shielding structure enclosing at least the electron source and the plurality of accelerating cavities of the accelerator guide, the shielding structure having an inner wall surface surrounding the accelerator guide;
wherein the accelerator guide further comprises a guide-slide at the second end providing a contact surface slidably engaging the inner wall surface of the shielding structure.

20. The apparatus of claim 19 , wherein the guide-slide has a contour as viewed in the longitudinal axis, and wherein the inner wall surface of the shielding structure has a contour as viewed in the longitudinal axis generally conformal to the contour of the guide-slide.

21. The apparatus of claim 20 , wherein the contour of the guide-slide and the contour of the inner wall surface of the shielding structure are generally in an oval shape.

22. The apparatus of claim 20 , wherein the contour of the guide-slide and the contour of the inner wall surface of the shielding structure are generally in an obround shape.

23. The apparatus of claim 20 , wherein the shielding structure comprises a mono-block surrounding at least a major portion of the accelerator guide.

24. The apparatus of claim 23 , wherein the mono-block comprises a radiation shield and a magnetic shield integrated with the radiation shield.

25. The apparatus of claim 24 , wherein the mono-block comprises a mounting interface.

26. The apparatus of claim 25 , further comprising a mounting flange coupled to the first end of the accelerator guide for securing the accelerator guide to the mono-block via the mounting interface.

27. The apparatus of claim 20 , wherein the mono-block comprises a cut-away providing clearance for a waveguide coupled to the accelerator guide.

28. The apparatus of claim 19 , wherein the accelerator guide comprises a plurality of side cavities each coupling two adjacent accelerating cavities, wherein adjacent side cavities of the accelerator guide form gaps therebetween.

29. The apparatus of claim 28 , further comprising radiation attenuating materials disposed in the gaps, wherein the radiation attenuating materials comprise lead or tungsten BBs, tungsten loaded epoxy, or shielding pieces.

30. A shielding structure, comprising:
a radiation shield; and
a magnetic shield comprising a ferromagnetic metal or alloy, wherein the radiation shield and magnetic shield are integrated in the form of a mono-block providing an internal volume configured to surround at least a major portion of an accelerator guide.

31. The radiation shi

Assignees

• Varian Med Sys Inc

Inventors

• Trail Mark E
• Gaderlund Blake H

Classifications

• A61N2005/1094

  Shielding, protecting against radiation · CPC title

• A61N5/1077

  Beam delivery systems · CPC title

• H05H9/00

  Linear accelerators · CPC title

• H05H7/22 Primary

  Details of linear accelerators, e.g. drift tubes (H05H7/02 - H05H7/20 take precedence) · CPC title

• A61N2005/1095

  Elements inserted into the radiation path within the system, e.g. filters or wedges · CPC title