According to one embodiment, a particle beam accelerator comprising: an injection unit configured to inject a particle beam; a guiding unit configured to guide the particle beam to a trajectory; an acceleration unit configured to accelerate the particle beam circulating on the trajectory; an emission unit configured to output the particle beam; a particle beam blocking unit configured to block the particle beam on the trajectory; a control unit configured to control the injection unit, the guiding unit, the acceleration unit, the emission unit, and the particle beam blocking unit, wherein: the guiding unit includes a superconducting electromagnet and a superconducting electromagnet interrupter configured to interrupt the superconducting electromagnet, the control unit is configured to change a starting sequence of the particle beam blocking unit and the superconducting electromagnet interrupter depending on at least an operating state of the emission unit, when an abnormality occurs in the superconducting electromagnet.

This disclosure relates to apparatuses and methods for the extraction of particle beams while maintaining the energy levels and precision of the particles and the particle beam. Apparatuses and methods for extracting a charged particle beam from a central orbit in a synchrotron are provided, in which a particle beam is deflected from the central orbit. Parts of the deflected particle beam passes through a stripping foil placed in at least parts of the deflected path such that the particles that pass through the foil are stripped of at least one electron. The electron stripped particles and the non-stripped particles may be separated magnetically.

This disclosure relates to apparatuses and methods for the extraction of particle beams while maintaining the energy levels and precision of the particles and the particle beam. Apparatuses and methods for extracting a charged particle beam from a central orbit in a synchrotron are provided, in which a particle beam is deflected from the central orbit. Parts of the deflected particle beam passes through a stripping foil placed in at least parts of the deflected path such that the particles that pass through the foil are stripped of at least one electron. The electron stripped particles and the non-stripped particles may be separated magnetically.

A device controller controls an acceleration-related devices and an extraction-related devices of an accelerator for accelerating and extracting a particle beam, in such a way that the controller checks, at a time point when receiving a master clock pulse, that preparation for operating the acceleration-related devices is completed and then commands the acceleration-related devices to operate in accordance with an operation pattern corresponding to a prescribed energy of the particle beam, and commands the acceleration-related devices to operate in accordance with an extracting operation pattern when an extraction enable signal indicating that the particle beam reaches the prescribed energy is turned ON and an extraction-related device setting-status signal indicating that completion of setting the extraction-related devices for the prescribed energy is ON.

There is provided a circular accelerator that accelerates a beam of charged particles circulating in a magnetic field such that a closed orbit for each energy of the beam is eccentric. The circular accelerator includes a beam extraction port for extracting beams of different energies from the closed orbit, a first bending magnet and a second bending magnet that bend the beam extracted from the beam extraction port, and a control unit that controls magnetic field strengths of the first bending magnet and the second bending magnet in accordance with the energy of the extracted beam. When the energy of the extracted beam is a designed maximum energy of the circular accelerator, the control unit excites both the first bending magnet and the second bending magnet to bend the beam.

There is provided a circular accelerator that accelerates a beam of charged particles circulating in a magnetic field such that a closed orbit for each energy of the beam is eccentric. The circular accelerator includes a beam extraction port for extracting beams of different energies from the closed orbit, a first bending magnet and a second bending magnet that bend the beam extracted from the beam extraction port, and a control unit that controls magnetic field strengths of the first bending magnet and the second bending magnet in accordance with the energy of the extracted beam. When the energy of the extracted beam is a designed maximum energy of the circular accelerator, the control unit excites both the first bending magnet and the second bending magnet to bend the beam.

A rotating capacitor is used in a circular accelerator that accelerates a charged particle beam by feeding a first radio frequency to a DC main magnetic field. The rotating capacitor modulates a frequency of the first radio frequency. The rotating capacitor includes a stator electrode and a rotor electrode used for modulating the frequency of the first radio frequency together with the stator electrode. A vacuum seal performs vacuum sealing around a shaft for rotating the rotor electrode. A bearing that supports the shaft is installed on an atmosphere side.

A rotating capacitor is used in a circular accelerator that accelerates a charged particle beam by feeding a first radio frequency to a DC main magnetic field. The rotating capacitor modulates a frequency of the first radio frequency. The rotating capacitor includes a stator electrode and a rotor electrode used for modulating the frequency of the first radio frequency together with the stator electrode. A vacuum seal performs vacuum sealing around a shaft for rotating the rotor electrode. A bearing that supports the shaft is installed on an atmosphere side.

A control method for an accelerator according to the present embodiment is a control method for an accelerator that supplies a current generating a magnetic field to a plurality of deflection electromagnets based on a current-value instruction signal. The method includes providing a flat region that makes a current value of the deflection electromagnet constant in a case of an acceleration cycle involving emission of the charged particles, not providing the flat region in the current-value instruction signal in a case of an acceleration cycle, smoothing time change of a current value in a transition of the current value to the flat region or a transition from the flat region, and determining a time required for the smoothing based on a predetermined energy for extracting the charged particles or a difference between energies before and after change to the predetermined extraction energy.

A control method for an accelerator according to the present embodiment is a control method for an accelerator that supplies a current generating a magnetic field to a plurality of deflection electromagnets based on a current-value instruction signal. The method includes providing a flat region that makes a current value of the deflection electromagnet constant in a case of an acceleration cycle involving emission of the charged particles, not providing the flat region in the current-value instruction signal in a case of an acceleration cycle, smoothing time change of a current value in a transition of the current value to the flat region or a transition from the flat region, and determining a time required for the smoothing based on a predetermined energy for extracting the charged particles or a difference between energies before and after change to the predetermined extraction energy.