Patent Number: 
Section: claims

1. A beam diffuser selector apparatus for a particle accelerator, comprising:a movable member having a plurality of beam diffusers mounted thereon, each of the plurality of beam diffusers having a different predetermined thickness; anda driving device coupled to the movable member, the driving device configured to selectively move the movable member such that a selected one of the plurality of beam diffusers is positioned in a test position which is adjacent to an output of the particle accelerator and between the output of the particle accelerator and a device under test. 2. The beam diffuser selector apparatus of claim 1, wherein the movable member has at least one diagnostic tool mounted thereon; and wherein the driving device is configured to selectively move the movable member such that a selected one of the plurality of beam diffusers or a selected one of the at least one diagnostic tool is positioned in the test position. 3. The beam diffuser selector apparatus of claim 2, wherein the at least one diagnostic tool is one or more of a laser apparatus, a phosphor screen, and a radiochromatic film. 4. The beam diffuser selector apparatus of claim 1, wherein the movable member has a partial ring member coupled to a hub member via a plurality of spoke members. 5. The beam diffuser selector apparatus of claim 4, wherein the movable member has a counterweight coupled to the hub member via an additional spoke member, the counterweight positioned opposite the partial ring member. 6. The beam diffuser selector apparatus of claim 1, wherein the driving device has a motor that drives a shaft that is connected to the movable member. 7. The beam diffuser selector apparatus of claim 6, wherein the motor is a stepper motor; and wherein the driving device has a resolver coupled to the shaft to provide feedback about a position of the movable member. 8. The beam diffuser selector apparatus of claim 7, further comprising a controller coupled to the stepper motor and the resolver, the controller configured to cause the stepper motor to rotate to position a selected one of the plurality of beam diffusers in the test position. 9. The beam diffuser selector apparatus of claim 1, wherein the driving device is mounted on a moveable platform and further comprising a retraction device that has a pneumatic cylinder coupled to the moveable platform that selectively retracts the movable member away from the output of the particle accelerator. 10. A beam diffuser selector system for a particle accelerator, comprising:a movable member having a plurality of beam diffusers mounted thereon, each of the plurality of beam diffusers having a different predetermined thickness;a driving device coupled to the movable member, the driving device configured to selectively move the movable member such that a selected one of the plurality of beam diffusers is positioned in a test position which is adjacent to an output of the particle accelerator and between the output of the particle accelerator and a device under test; anda controller coupled to the driving device, the controller having a user interface for receiving commands selecting a particular one of the plurality of beam diffusers and configured to provide control signals to the driving device to cause the driving device to selectively move the movable member such that the selected one of the plurality of beam diffusers is positioned in the test position. 11. The beam diffuser selector system of claim 10, wherein the movable member has at least one diagnostic tool mounted thereon; wherein the driving device is configured to selectively move the movable member such that a selected one of the plurality of beam diffusers or a selected one of the at least one diagnostic tool is positioned in the test position; wherein the user interface is for receiving commands selecting a particular one of the plurality of beam diffusers or of the at least one diagnostic tool; and wherein the controller is configured to provide control signals to the driving device to cause the driving device to selectively move the movable member such that the selected particular one of the plurality of beam diffusers or of the at least one diagnostic tool is positioned in the test position. 12. The beam diffuser selector system of claim 11, wherein the at least one diagnostic tool is one or more of a laser apparatus, a phosphor screen, and a radiochromatic film. 13. The beam diffuser selector system of claim 10, wherein the movable member has a partial ring member coupled to a hub member via a plurality of spoke members. 14. The beam diffuser selector system of claim 13, wherein the movable member has a counterweight coupled to the hub member via an additional spoke member, the counterweight positioned opposite the partial ring member. 15. The beam diffuser selector system of claim 10, wherein the driving device has a motor that drives a shaft that is connected to the movable member. 16. The beam diffuser selector system of claim 15, wherein the motor is a stepper motor; and wherein the driving device has a resolver coupled to the shaft to provide feedback about a position of the movable member. 17. The beam diffuser selector system of claim 16, wherein the controller is coupled to the stepper motor and the resolver and is configured to cause the stepper motor to rotate to position a selected one of the plurality of beam diffusers in the test position. 18. The beam diffuser selector system of claim 10, wherein the movable member and the driving device are positioned adjacent to the particle accelerator within a test chamber and wherein the controller is mounted outside the test chamber. 19. A method of operating a beam diffuser selector apparatus for a particle accelerator, the beam diffuser selector apparatus including a movable member having a plurality of beam diffusers mounted thereon, each of the plurality of beam diffusers having a different predetermined thickness, and a driving device coupled to the movable member, comprising the steps of:selecting one of the plurality of beam diffusers for use in a test; andcausing the driving device to move the movable member such that the selected one of the plurality of beam diffusers is positioned in a test position which is adjacent to an output of the particle accelerator and between the output of the particle accelerator and a device under test. 20. The method of claim 19, further comprising the step of retracting the movable member away from the output of the particle accelerator once the test is complete.