A synchrocyclotron .[.comprises.]. .Iadd.includes .Iaddend.a resonant circuit that includes electrodes having a gap therebetween across the magnetic field. An oscillating voltage input, having a variable amplitude and frequency determined by a programmable digital waveform generator generates an oscillating electric field across the gap. The synchrocyclotron can include a variable capacitor in circuit with the electrodes to vary the resonant frequency. The synchrocyclotron can further include an injection electrode and an extraction electrode having voltages controlled by the programmable digital waveform generator. The synchrocyclotron can further include a beam monitor. The synchrocyclotron can detect resonant conditions in the resonant circuit by measuring the voltage .[.and or.]. .Iadd.and/or .Iaddend.current in the resonant circuit, driven by the input voltage, and adjust the capacitance of the variable capacitor or the frequency of the input voltage to maintain the resonant conditions. The programmable waveform generator can adjust at least one of the oscillating voltage input, the voltage on the injection electrode and the voltage on the extraction electrode according to beam intensity and in response to changes in resonant conditions.

A synchrocyclotron .[.comprises.]. .Iadd.includes .Iaddend.a resonant circuit that includes electrodes having a gap therebetween across the magnetic field. An oscillating voltage input, having a variable amplitude and frequency determined by a programmable digital waveform generator generates an oscillating electric field across the gap. The synchrocyclotron can include a variable capacitor in circuit with the electrodes to vary the resonant frequency. The synchrocyclotron can further include an injection electrode and an extraction electrode having voltages controlled by the programmable digital waveform generator. The synchrocyclotron can further include a beam monitor. The synchrocyclotron can detect resonant conditions in the resonant circuit by measuring the voltage .[.and or.]. .Iadd.and/or .Iaddend.current in the resonant circuit, driven by the input voltage, and adjust the capacitance of the variable capacitor or the frequency of the input voltage to maintain the resonant conditions. The programmable waveform generator can adjust at least one of the oscillating voltage input, the voltage on the injection electrode and the voltage on the extraction electrode according to beam intensity and in response to changes in resonant conditions.

An example particle therapy system may include: a synchrocyclotron to produce a particle beam; a scanner to move the particle beam in one or more dimensions relative to an irradiation target; and an energy degrader that is between the scanner and the irradiation target. The energy degrader may include multiple plates that are movable relative to a path of the particle beam, with the multiple plates each being controllable to move while in the path of the particle beam and during movement of the particle beam. An aperture may be between the energy degrader and the irradiation target. The aperture being may be to trim the particle beam prior to the particle beam reaching the irradiation target.

An example particle therapy system may include: a synchrocyclotron to produce a particle beam; a scanner to move the particle beam in one or more dimensions relative to an irradiation target; and an energy degrader that is between the scanner and the irradiation target. The energy degrader may include multiple plates that are movable relative to a path of the particle beam, with the multiple plates each being controllable to move while in the path of the particle beam and during movement of the particle beam. An aperture may be between the energy degrader and the irradiation target. The aperture being may be to trim the particle beam prior to the particle beam reaching the irradiation target.

An example device for trimming a particle beam includes: structures made of material that blocks passage of the particle beam, with the structures being configurable to define an edge that is movable into a path of the particle beam; and linear motors that are controllable to configure the structures to define the edge.

An example device for trimming a particle beam includes: structures made of material that blocks passage of the particle beam, with the structures being configurable to define an edge that is movable into a path of the particle beam; and linear motors that are controllable to configure the structures to define the edge.

An accelerator includes: a main magnetic field magnet that has a plurality of magnetic poles and excites the main magnetic field in a space interposed between the magnetic poles; a magnetic channel that extracts the ion beam from an inside of the main magnetic field magnet toward an outside of the main magnetic field magnet; a displacement unit that displaces the ion beam circulating in a main magnetic field region to an outer side of the main magnetic field region; and a disturbance magnetic field region that is provided in an outer peripheral portion of the main magnetic field region and excites a magnetic field which disturbs the ion beam displaced to the outer side and guides the ion beam to the magnetic channel, the magnetic channel including a predetermined mechanism that suppresses a magnetic field gradient generated radially inward in the circulating ion beam region.

An accelerator includes: a main magnetic field magnet that has a plurality of magnetic poles and excites the main magnetic field in a space interposed between the magnetic poles; a magnetic channel that extracts the ion beam from an inside of the main magnetic field magnet toward an outside of the main magnetic field magnet; a displacement unit that displaces the ion beam circulating in a main magnetic field region to an outer side of the main magnetic field region; and a disturbance magnetic field region that is provided in an outer peripheral portion of the main magnetic field region and excites a magnetic field which disturbs the ion beam displaced to the outer side and guides the ion beam to the magnetic channel, the magnetic channel including a predetermined mechanism that suppresses a magnetic field gradient generated radially inward in the circulating ion beam region.

Conventional cyclotrons have been incapable of changing energy of a beam to be extracted. Conventional synchrotrons have been difficult to output beams in a continuous manner. An accelerator has a dense region dense region in which orbits of different energies densely gather as a result of using a radiofrequency electric field to accelerate an ion orbiting in an isochronous magnetic field in order to cause a beam orbit to be displaced in a specific direction with increasing acceleration, and a sparse region in which orbits of different energies are sparsely discrete from each other. The accelerator has a feature that a magnetic field has a magnetic field gradient in a radial direction of a beam orbit in the dense region, and a product of a gradient of magnetic field gradient and a beam size passing through the dense region becomes smaller than the magnetic field gradient.

Conventional cyclotrons have been incapable of changing energy of a beam to be extracted. Conventional synchrotrons have been difficult to output beams in a continuous manner. An accelerator has a dense region dense region in which orbits of different energies densely gather as a result of using a radiofrequency electric field to accelerate an ion orbiting in an isochronous magnetic field in order to cause a beam orbit to be displaced in a specific direction with increasing acceleration, and a sparse region in which orbits of different energies are sparsely discrete from each other. The accelerator has a feature that a magnetic field has a magnetic field gradient in a radial direction of a beam orbit in the dense region, and a product of a gradient of magnetic field gradient and a beam size passing through the dense region becomes smaller than the magnetic field gradient.