Patent Number: 
Section: claims

1. An energy modulator for use with a particle source that provides a beam of particles, comprising:a first block moveable between a first position and a second position, wherein when the first block is at the first position, it is out of a path of the beam, and wherein when the first block is at the second position, it is in the path of the beam; anda second block moveable relative to the first block, wherein the second block and the first block are offset from each other in a direction of the beam;wherein the first block has a first energy absorption characteristic, and the second block has a second energy absorption characteristic that is different from the first energy absorption characteristic; andwherein the first block is moveable between the first position and the second position as a single unit, and has a size sufficient to traverse an entire cross section of the beam when the first block is at the second position. 2. The energy modulator of claim 1, wherein the first block has a first thickness, and the second block has a second thickness that is different from the first thickness. 3. The energy modulator of claim 1, wherein the first block has a thickness, and the second block has a thickness that is two times the thickness of the first block. 4. The energy modulator of claim 1, wherein the first block is made from a first material, and the second block is made from a second material that is different from the first material. 5. The energy modulator of claim 1, wherein the first block is made from a first material and has a first thickness, and the second block is made from a second material and has a second thickness, the second material being different from the first material, and the second thickness being different from the first thickness. 6. The energy modulator of claim 1, wherein the first block is made from a material that is at least partially transparent to the particle beam. 7. The energy modulator of claim 1, further comprising a third block, wherein the first, second, and third blocks are offset relative to each other in a direction of the beam. 8. The energy modulator of claim 7, wherein the third block has a thickness that is four times the thickness of the first block, and the second block has a thickness that is two times the thickness of the first block. 9. The energy modulator of claim 1, further comprising a positioner for moving the first block. 10. The energy modulator of claim 9, wherein the positioner is driven by hydraulics, a pneumatic mechanism, a rotating motor, or a linear motor. 11. The energy modulator of claim 1, wherein a surface of the first block is perpendicular to the beam. 12. The energy modulator of claim 1, further comprising a first mounting structure to which the first and the second blocks are slidably mounted. 13. The energy modulator of claim 12, wherein the first mounting structure is mounted to a particle delivery system having the particle source, a particle transport system, and a nozzle. 14. The energy modulator of claim 13, wherein the first mounting structure is mounted to the particle delivery system such that the first mounting structure is closer to the particle source than the nozzle. 15. The energy modulator of claim 14, further comprising a second mounting structure to which a plurality of blocks are slidably mounted, wherein the second mounting structure is mounted to the particle delivery system such that the second mounting structure is closer to the nozzle than the particle source. 16. The energy modulator of claim 15, wherein the first block is made from a first material, the second block is made from a second material, and the second material has a Z value that is less than a Z value of the first material. 17. The energy modulator of claim 1, further comprising a cooling system coupled to the first block, the second block, or both. 18. The energy modulator of claim 1, further comprising an energy sensor, and a control coupled to the energy sensor, wherein the control is configured to adjust a position of the first block based on a feedback signal provided by the energy sensor. 19. The energy modulator of claim 1, wherein the particle source comprises a proton source. 20. The energy modulator of claim 1, further comprising a frame having a first side and a second side, wherein the first block has a thickness that is less than 1 cm and is mounted between the first and second sides. 21. The energy modulator of claim 20, further comprising a cooling system for providing cooling to the first block via convection. 22. The energy modulator of claim 1, further comprising a shield for protecting a patient from being irradiated by neutrons generated as a result of an interaction between the beam and one of the blocks. 23. The energy modulator of claim 1, wherein the first block comprises a solid portion that is moveable relative to the path of the beam. 24. The energy modulator of claim 1, wherein the first block, when placed in the path of the beam, is aligned with a longitudinal axis of a particle accelerator. 25. An energy modulator for use with a particle source that provides a beam of particles, comprising:a first block moveable between a first position and a second position, wherein when the first block is at the first position, it is out of a path of the beam, and wherein when the first block is at the second position, it is in the path of the beam; anda second block moveable relative to the first block, wherein the second block and the first block are offset from each other in a direction of the beam;wherein the first block and the second block are at least partially transparent to the particle beam, the first block having a surface that is perpendicular to the beam; andwherein the first block is moveable between the first position and the second position as a single unit, and has a size sufficient to traverse an entire cross section of the beam when the first block is at the second position. 26. The energy modulator of claim 25, further comprising a third block, wherein the first, second, and third blocks are offset from each other in a direction of the beam. 27. The energy modulator of claim 26, wherein the third block has a thickness that is four times the thickness of the first block. 28. The energy modulator of claim 26, wherein, the third block is moveable relative to the first block and the second block. 29. The energy modulator of claim 25, further comprising a positioner for moving the first block. 30. The energy modulator of claim 29, wherein the positioner is driven by hydraulics or pneumatically. 31. The energy modulator of claim 29, wherein the positioner is driven by a rotating or linear motor. 32. The energy modulator of claim 25, wherein the first block has an opposite surface that is parallel to the surface. 33. The energy modulator of claim 25, further comprising a first mounting structure to which the first and the second blocks are slidably mounted. 34. The energy modulator of claim 33, wherein the first mounting structure is mounted to a particle delivery system having the particle source, a particle transport system, and a nozzle. 35. The energy modulator of claim 34, wherein the first mounting structure is mounted to the particle delivery system such that the first mounting structure is closer to the particle source than the nozzle. 36. The energy modulator of claim 35, further comprising a second mounting structure to which a plurality of blocks are slidably mounted, wherein the second mounting structure is mounted to the particle delivery system such that the second mounting structure is closer to the nozzle than the particle source. 37. The energy modulator of claim 25, wherein the first block is made from a first material, and the second block is made from a second material that is different from the first material. 38. The energy modulator of claim 37, wherein the second material has a Z value that is less than a Z value of the first material. 39. The energy modulator of claim 25, further comprising a cooling system coupled to the first block, the second block, or both. 40. The energy modulator of claim 25, further comprising an energy sensor, and a control coupled to the energy sensor, wherein the control is configured to adjust a position of the first block based on a feedback signal provided by the energy sensor. 41. The energy modulator of claim 25, wherein the particle source comprises a proton source. 42. The energy modulator of claim 25, further comprising a frame having a first side and a second side, wherein the first block has a thickness that is less than 1 cm and is mounted between the, first and second sides. 43. The energy modulator of claim 42, further comprising a cooling system for providing cooling to the first block via convection. 44. The energy modulator of claim 25, wherein the second block has a thickness that is two times a thickness of the first block. 45. The energy modulator of claim 44, wherein the thickness of the second block is measured in a direction of the beam. 46. The energy modulator of claim 25, wherein the first block comprises a solid portion that is moveable relative to the path of the beam. 47. The energy modulator of claim 25, wherein the first block, when placed in the path of the beam, is aligned with a longitudinal axis of a particle accelerator. 48. An energy modulator for use with a particle source that provides a beam of particles, comprising:a first block moveable between a first position and a second position, wherein when the first block is at the first position, it is out of a path of the beam, and wherein when the first block is at the second position, it is in the path of the beam; anda second block moveable relative to the first block, wherein the second block and the first block are offset from each other in a direction of the beam;wherein the first block and the second block are at least partially transparent to the particle beam, and wherein the first block is made from a first material, the second block is made from a second material that is different from the first material; andwherein the first block is moveable between the first position and the second position as a single unit, and has a size sufficient to traverse an entire cross section of the beam when the first block is at the second position. 49. The energy modulator of claim 48, further comprising a third block, wherein the first, second, and third blocks are offset relative to each other in a direction of the beam. 50. The energy modulator of claim 49, wherein the second block has a thickness that is two times a thickness of the first block, and the third block has a thickness that is four times the thickness of the first block. 51. The energy modulator of claim 49, wherein the third block is moveable relative to the first block and the second block. 52. The energy modulator of claim 48, further comprising a positioner for moving the first block. 53. The energy modulator of claim 52, wherein the positioner is driven by hydraulics or a pneumatic mechanism. 54. The energy modulator of claim 52, wherein the positioner is driven by a rotating or linear motor. 55. The energy modulator of claim 48, wherein the first block comprises a rectangular block. 56. The energy modulator of claim 48, wherein a surface of the first block is perpendicular to the beam. 57. The energy modulator of claim 48, further comprising a first mounting structure to which the first and the second blocks are slidably mounted. 58. The energy modulator of claim 57, wherein the first mounting structure is mounted to a particle delivery system having the particle source, a particle transport system, and a nozzle. 59. The energy modulator of claim 58, wherein the first mounting structure is mounted to the particle delivery system such that the first mounting structure is closer to the particle source than the nozzle. 60. The energy modulator of claim 59, further comprising a second mounting structure to which a plurality of blocks are slidably mounted, wherein the second mounting structure is mounted to the particle delivery system such that the second mounting structure is closer to the nozzle than the particle source. 61. The energy modulator of claim 48, wherein the second material has a Z value that is less than a Z value of the first material. 62. The energy modulator of claim 48, further comprising a cooling system coupled to the first block, the second block, or both. 63. The energy modulator of claim 48, further comprising an energy sensor, and a control coupled to the energy sensor, wherein the control is configured to adjust a position of the first block based on a feedback signal provided by the energy sensor. 64. The energy modulator of claim 48, wherein the particle source comprises a proton source. 65. The energy modulator of claim 48, further comprising a frame having a first side and a second side, wherein the first block has a thickness that is less than 1 cm and is mounted between the first and second sides. 66. The energy modulator of claim 65, further comprising a cooling system for providing cooling to the first block via convection. 67. The energy modulator of claim 48, wherein the first block comprises a solid portion that is moveable relative to the path of the beam. 68. The energy modulator of claim 48, wherein the first block, when placed in the path of the beam, is aligned with a longitudinal axis of a particle accelerator. 69. A method for modulating an energy of a particle beam, comprising:determining information regarding a desired particle beam energy;determining a combination of blocks to be placed in a path of a beam based on the determined information, wherein the blocks are offset from each other in a direction of the beam; andpositioning the blocks such that they are in the path of the beam;wherein at least one of the blocks includes a solid portion that is positionable from a first location that is out of the path of the beam, to a second location that is in the path of the beam; andwherein the at least one of the blocks is moveable between the first location and the second location as a single unit, and has a size sufficient to traverse an entire cross section of the beam when the at least one of the blocks is at the second position. 70. The method of claim 69, wherein the particle beam comprises a proton beam. 71. The method of claim 69, wherein the act of determining the combination of blocks comprises selecting the blocks from a set of blocks, each of the blocks in a part of the set having a thickness that is different from the remaining blocks in the part of the set. 72. The method of claim 71, wherein one of the blocks in the part of the set has a thickness that is two times a thickness of another one of the blocks in the part of the set. 73. The method of claim 69, wherein the blocks are at least partially transparent to the beam. 74. The method of claim 69, wherein each of the blocks has two surfaces that are parallel to each other. 75. The method of claim 69, wherein one of the blocks has a Z value that is different from a Z value of another one of the blocks. 76. The method of claim 69, further comprising cooling the blocks. 77. The method of claim 76, wherein one of the blocks is cooled using liquid, and another one of the blocks is cooled using convection. 78. The method of claim 69, wherein the act of determining the information regarding the desired particle beam energy comprises obtaining the information from a treatment plan. 79. The method of claim 69, wherein the act of determining the information regarding the desired particle beam energy comprises: measuring an energy of a delivered beam; and determining a difference between the measured energy and a desired energy, wherein the information comprises the determined difference. 80. The method of claim 69, wherein the blocks comprise respective solid portions that are moveable relative to each other.