Patent Number: 
Section: claims

1. An assembly comprising:a body,one or more collimators supported by the body, each of the one or more collimators having a through hole configured to define a shape or size of a treatment beam having a beam centerline, one or more photon flattening filters supported by the body, and one or more electron scattering foils supported by the body, wherein said one or more collimators and said one or more photon flattening filters are positioned in a circular or arc configuration having a first radius, and said one or more electron scattering foils are positioned in a circular or arc configuration having a second radius different from the first radius; anda first axis operable to move the body, and a second axis operable to move the body, wherein said first axis is a linear axis operable to translate the body and said second axis is a rotational axis operable to rotate the body about a line parallel to the beam centerline, wherein the first and second axes are operable to align one of the one or more collimators, photon flattening filters, or electron scattering foils with the treatment beam. 2. The assembly of claim 1, wherein said first axis is operable to translate the second axis. 3. The assembly of claim 1 wherein said second axis is operable to rotate the first axis. 4. The assembly of claim 1 further comprising a second axis operable to move the body, wherein said first and second axes are linear axes. 5. The assembly of claim 1 wherein said first axis is a linear axis operable to translate the body and said second axis is a rotational axis operable to rotate the body, and said first axis is further operable to translate the second axis. 6. The assembly of claim 1 further comprising a field light assembly comprising a mirror member and one or more light sources, said mirror member being supported by the body. 7. The assembly of claim 1 further comprising a target assembly comprising one or more targets configured to produce radiation upon impingement by electrons and a third axis operable to move the target assembly. 8. The assembly of claim 7 further comprising an ion chamber assembly and a fourth axis operable to move the ion chamber assembly, wherein each of the one or more collimators is configured to allow a portion of the treatment beam to pass through an outside area of the collimator to be projected onto and detected by the ion chamber. 9. The assembly of claim 1 wherein the first axis comprises a servo motor and one or more feedback devices. 10. The assembly of claim 1 wherein each of the one or more collimators has a conically-, cylindrically-, or trapezoidally-shaped hole configured to define a treatment beam for radiosurgery. 11. A radiation apparatus comprising a linear accelerator, a treatment head, and a gantry enclosing the linear accelerator and the treatment head, the radiation apparatus comprising:a radiation source configured to produce a treatment beam;a primary collimator configured to generally define a field of the treatment beam;one or more stereotactic radiosurgery (SRS) collimators supported by a body movable relative to the radiation source to align one of the one or more SRS Collimators with the treatment beam, each of the one or more SRS collimators having a through hole configured to further collimate the treatment beam to provide a beam suitable for radiosurgery, and each of the one or more SRS collimators having a size to allow a portion of the treatment beam to pass around an outside area of the each of the one or more SRS collimators to be projected onto an ion chamber;the ion chamber configured to detect the portion of the treatment beam passing around the outside area of the each of the one or more SRS collimators; andone or more collimation jaws configured to block at least a portion of the treatment beam passing around the outside area of the each of the one or more SRS collimators and through the ion chambers. 12. The radiation apparatus of claim 11 wherein each of the one or more SRS collimators has a conically-, cylindrically-, or trapezoidally-shaped through hole to define the treatment beam. 13. The radiation apparatus of claim 11 wherein the radiation source comprises a target configured to produce radiation upon impingement by electrons, and said target resides in the treatment head. 14. The radiation apparatus of claim 11 wherein said one or more SRS collimators are movable relative to the radiation source. 15. The radiation apparatus of claim 11 further comprisingone or more photon flattening filters and/or one or more electron scattering foils supported by the body; anda first and a second axes operable to move the body. 16. The radiation apparatus of claim 15 wherein said one or more collimators and said one or more photon flattening filters are arranged in a circular or arc configuration having a first radius, said one or more electron scattering foils are arranged in a circular or arc configuration having a second radius different from the first radius. 17. The radiation apparatus of claim 16 wherein said first axis is a linear axis operable to translate the body and said second axis is a rotational axis operable to rotate the body. 18. The radiation apparatus of claim 17, wherein said first axis is operable to translate the second axis. 19. The radiation apparatus of claim 17 wherein said second axis is operable to rotate the first axis. 20. The radiation apparatus of claim 15 wherein the first and second axes are linear axes. 21. A radiation system comprising:a radiation source operable to generate a radiation beam having a beam centerline;an assembly comprising a body, one or more collimators supported by the body each having a through hole configured to define a shape or size of a treatment beam, one or more photon flattening filters supported by the body, and one or more electron scattering foils supported by the body, wherein said one or more collimators and said one or more photon flattening filters are positioned in a circular or arc configuration having a first radius, and said one or more electron scattering foils are positioned in a circular or arc configuration having a second radius different from the first radius, and a first and a second axes operable to move the body relative to the radiation source, each of the first and second axes comprising a servo motor, wherein said first axis is a linear axis operable to translate the body and said second axis is a rotational axis operable to rotate the body about a line parallel to the beam centerline, and the first and second axes are operable to align one of the one or more collimators, photon flattening filters, or electron scattering foils with the treatment beam; anda controller programmed to control the servo motor of the first and second axes in moving the body to a desired position. 22. The radiation system of claim 21 wherein each of the first and a second axes further comprises one or more feedback devices, and the controller is further programmed to control the servo motor of the first and second axes based on at least signals from the one or more feedback devices. 23. The radiation system of claim 21, wherein said first axis is operable to translate the second axis. 24. The radiation system of claim 21 wherein said second axis is operable to rotate the first axis. 25. The radiation system of claim 21 wherein said one or more collimators have a conically-, cylindrically-, or trapezoidally-shaped hole configured to define a treatment beam suitable for radiosurgery. 26. The radiation system of claim 21 further comprising an ion chamber and a third axis operable to move the ion chamber, wherein said third axis comprises a servo motor and said controller is further programmed to control the servo motor of the third axis in driving the ion chamber, wherein each of the one or more collimators is configured to allow a portion of the treatment beam to pass through an outside area of the collimator to be projected onto and detected by the ion chamber. 27. The radiation system of claim 26 further comprising a field light simulation system comprising a light source and a mirror member, said mirror member being supported by the body and movable by the first and second axes, and said light source being movable by the third axis. 28. The radiation system of claim 27 wherein the radiation source comprises a target assembly comprising one or more targets each being configured to produce radiation upon impingement by electrons, and a fourth axis operable to move the target assembly for positioning the one or more targets, wherein said fourth axis comprises a servo motor and the controller is further programmed to control the servo motor of the fourth axis in driving the target assembly to a desired position.