Patent ID: 8742699

Claim:
A method for operating a charged particle beam generator that includes a linear accelerator and a circular accelerator, wherein the linear accelerator operates in a predetermined operation cycle on the basis of a radiofrequency power supply for applying a pulse voltage for acceleration, and accelerates, at an operation timing based on the operation cycle, charged particles extracted from an ion source so as to cause a charged particle beam to be extracted from the linear accelerator; and wherein the circular accelerator operates in an operation cycle including a process of causing the charged particle beam to be injected into the circular accelerator, a process of accelerating the charged particle beam, a process of causing the charged particle beam to be extracted from the circular accelerator and a process of decelerating the charged particle beam, causes the charged particle beam accelerated by the linear accelerator to be injected into the circular accelerator at a predetermined timing, and causes the accelerated charged particle beam to be extracted from the circular accelerator, the method comprising the step of changing the operation timing of the linear accelerator after completion of the process of causing the charged particle beam to be extracted from the circular accelerator in the operation cycle of the circular accelerator so that the operation cycle of the linear accelerator temporarily increases and the operation timing of the linear accelerator matches an injection timing of the next operation cycle of the circular accelerator.