| 主权项 |
1. An apparatus for extracting a circulating charged particle beam from a synchrotron, said synchrotron having a center, said apparatus comprising: an extraction material; at least a one kilovolt direct current field applied across a pair of extraction blades; a deflector; a patient respiration monitor generating a respiration signal; and a main controller, wherein the circulating charged particle beam passes through said extraction material resulting in a reduced energy charged particle beam, wherein the reduced energy charged particle beam passes between said pair of extraction blades, wherein the direct current field redirects the reduced energy charged particle beam through said deflector, wherein said deflector yields an extracted charged particle beam, wherein said extraction material comprises a foil less than about one hundred fifty micrometers thick, wherein a radio frequency voltage applied across a first pair of blades is configured to induce a betatron oscillation on the circulating charged particle beam, 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 first blades, wherein the circulating charged particle beam comprises a radius of curvature passing through said first pair of 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, wherein timing of the extracted charged particle beam is synchronized to said respiration signal, and said main controller timing all of: (1) particle beam injection, (2) particle beam acceleration, and (3) timing of said radio frequency voltage to synchronize with said respiration signal. |
