In a circular accelerator that applies a radiofrequency wave in a main magnetic field to accelerate charged particle beam while increasing an orbit radius, another radiofrequency wave with a frequency different from the radiofrequency wave used for acceleration is applied to the charged particle beam in order to extract the charged particle beam. Thereby, in the circular accelerator that accelerates charged particle beam while increasing an orbit radius by applying a radiofrequency wave in a main magnetic field, the high precision control on extraction of the charged particle beam from the circular accelerator is achieved.

In a circular accelerator that applies a radiofrequency wave in a main magnetic field to accelerate charged particle beam while increasing an orbit radius, another radiofrequency wave with a frequency different from the radiofrequency wave used for acceleration is applied to the charged particle beam in order to extract the charged particle beam. Thereby, in the circular accelerator that accelerates charged particle beam while increasing an orbit radius by applying a radiofrequency wave in a main magnetic field, the high precision control on extraction of the charged particle beam from the circular accelerator is achieved.

An acceleration radiofrequency acceleration system capable of frequency modulation and feeding an acceleration radiofrequency wave for accelerating a beam, a radiofrequency kicker 70 feeding an extraction radiofrequency wave different in frequency, from the acceleration radiofrequency wave for extracting a beam, a peeler magnetic field region 44 and a regenerator magnetic field region 45 for forming a disturbance magnetic field region including a high-order magnetic field that includes a magnetic field component having a number of poles of two poles or more and that includes at least a quadrupole magnetic field component, a shim of a magnetic material, and a septum magnet 43, 43A, 43B having an inner peripheral side septum coil conductor 5, an outer peripheral side septum coil conductor 6, a coil conductor connecting portion 7, and a coil lead-out portion 8 are provided.

An acceleration radiofrequency acceleration system capable of frequency modulation and feeding an acceleration radiofrequency wave for accelerating a beam, a radiofrequency kicker 70 feeding an extraction radiofrequency wave different in frequency, from the acceleration radiofrequency wave for extracting a beam, a peeler magnetic field region 44 and a regenerator magnetic field region 45 for forming a disturbance magnetic field region including a high-order magnetic field that includes a magnetic field component having a number of poles of two poles or more and that includes at least a quadrupole magnetic field component, a shim of a magnetic material, and a septum magnet 43, 43A, 43B having an inner peripheral side septum coil conductor 5, an outer peripheral side septum coil conductor 6, a coil conductor connecting portion 7, and a coil lead-out portion 8 are provided.

In a magnetic device 1, on faces opposite to a middle plane 2 between an upper magnetic pole 8 and a lower magnetic pole 9, recesses 21a, 21b, 21c, and 21d and projections 22a, 22b, 22c, and 22d are alternately placed along a beam circling direction. In the projections 22a, 22b, 22c, and 22d, angle widths θ of the projections 22a, 22b, 22c, and 22d when viewed from the center O1 of a beam closed orbit is narrowed as beam energy is increased. On the outer circumferential region of the recess 21a on the upper magnetic pole 8 and the lower magnetic pole 9, the inlet of an extraction channel 1019 that extracts a beam accelerated to a predetermined energy to outside an accelerator 1004 is provided.

In a magnetic device 1, on faces opposite to a middle plane 2 between an upper magnetic pole 8 and a lower magnetic pole 9, recesses 21a, 21b, 21c, and 21d and projections 22a, 22b, 22c, and 22d are alternately placed along a beam circling direction. In the projections 22a, 22b, 22c, and 22d, angle widths θ of the projections 22a, 22b, 22c, and 22d when viewed from the center O1 of a beam closed orbit is narrowed as beam energy is increased. On the outer circumferential region of the recess 21a on the upper magnetic pole 8 and the lower magnetic pole 9, the inlet of an extraction channel 1019 that extracts a beam accelerated to a predetermined energy to outside an accelerator 1004 is provided.

In a circular accelerator that applies a radiofrequency wave in a main magnetic field to accelerate charged particle beam while increasing an orbit radius, another radiofrequency wave with a frequency different from the radiofrequency wave used for acceleration is applied to the charged particle beam in order to extract the charged particle beam. Thereby, in the circular accelerator that accelerates charged particle beam while increasing an orbit radius by applying a radiofrequency wave in a main magnetic field, the high precision control on extraction of the charged particle beam from the circular accelerator is achieved.

In a circular accelerator that applies a radiofrequency wave in a main magnetic field to accelerate charged particle beam while increasing an orbit radius, another radiofrequency wave with a frequency different from the radiofrequency wave used for acceleration is applied to the charged particle beam in order to extract the charged particle beam. Thereby, in the circular accelerator that accelerates charged particle beam while increasing an orbit radius by applying a radiofrequency wave in a main magnetic field, the high precision control on extraction of the charged particle beam from the circular accelerator is achieved.

An example method includes: receiving, from a treatment planning process, information that is based on a dose distribution for an irradiation target; and performing at least one of the following operations: moving structures to trim spots of a particle beam so that the spots of the particle beam approximate pre-trimmed spots for which characteristics are obtained based on the information received; moving structures to produce a trimming curve for a layer of an irradiation target based on a specification of a trimming curve for the layer included in the information received; moving structures to produce a single trimming curve for all radiation fields of an irradiation target based on specifications of the single trimming curve included in the information received; or moving structures based on configuration information for the structures in the information received.

An example method includes: receiving, from a treatment planning process, information that is based on a dose distribution for an irradiation target; and performing at least one of the following operations: moving structures to trim spots of a particle beam so that the spots of the particle beam approximate pre-trimmed spots for which characteristics are obtained based on the information received; moving structures to produce a trimming curve for a layer of an irradiation target based on a specification of a trimming curve for the layer included in the information received; moving structures to produce a single trimming curve for all radiation fields of an irradiation target based on specifications of the single trimming curve included in the information received; or moving structures based on configuration information for the structures in the information received.