EMITTING METHOD OF CHARGED PARTICLE BEAM AND PARTICLE BEAM IRRADIATION SYSTEM

PROBLEM TO BE SOLVED: To suppress irradiation displacement of beams in a depth direction in the body of a patient. SOLUTION: When a difference between a frequency Fmes of an acceleration high-frequency signal at finish of beam acceleration and a target frequency Fdes is in a tolerance range of ±Ferr, an energy compensation device 27 sequentially calculates compensation frequency data of a time-wise smooth change to make the frequency Fmes the target frequency Fdes. A high-frequency control device 24 sequentially sets the compensation frequency data on a high-frequency oscillator 11. The high-frequency oscillator 11 sequentially impresses the high-frequency signal of the frequency output, based on the compensation frequency data on an acceleration cavity 10 provided at a synchrotron 3. With this, beam energy going around the inside of the synchrotron 3 matches with a target energy after acceleration. The beam reaching the target energy is emitted from the synchrotron 3 and irradiated onto a patient from an irradiation field forming device 16. COPYRIGHT: (C)2006,JPO&NCIPI