Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: To provide a preferred device configuration and arrangement capable of forming a large irradiation field, miniaturizing a gantry and reducing weight of the gantry. A gantry includes a bending magnet configured to bend a beam orbit, a plurality of horizontal direction scanning magnets which are first scanning magnets configured to scan the beam orbit in a horizontal direction which is a first direction, and a vertical direction scanning magnet which is a second scanning magnet configured to scan the beam orbit in a vertical direction which is a second direction. The plurality of horizontal direction scanning magnets is arranged so that ? is equal to or less than 90° when it is assumed that a phase difference between the horizontal direction scanning magnets is 180n°±?. The bending magnet is arranged between the plurality of horizontal direction scanning magnets.

Abstract: A circular accelerator of the present invention includes an electrode that applies a high frequency electric field for accelerating a charged particle beam, an electromagnetic device that bends the charged particle beam, and a direct current (or DC) power supply device that applies a direct current (or DC) electric field to the previous described electrode.

Abstract: To provide a preferred device configuration and arrangement capable of forming a large irradiation field, miniaturizing a gantry and reducing weight of the gantry. A gantry includes a bending magnet configured to bend a beam orbit, a plurality of horizontal direction scanning magnets which are first scanning magnets configured to scan the beam orbit in a horizontal direction which is a first direction, and a vertical direction scanning magnet which is a second scanning magnet configured to scan the beam orbit in a vertical direction which is a second direction. The plurality of horizontal direction scanning magnets is arranged so that ? is equal to or less than 90° when it is assumed that a phase difference between the horizontal direction scanning magnets is 180n°±?. The bending magnet is arranged between the plurality of horizontal direction scanning magnets.

Abstract: To provide a magnetic field control apparatus capable of reducing a width of a correcting plate. The magnetic field control apparatus includes a conductive vacuum duct 1 disposed between dipole magnet magnetic poles 3 and a conductive correcting plate 2. The correcting plate 2 is formed of a material having an electric conductivity higher than that of the vacuum duct 1. A plurality of conductive correcting plates 2 are disposed in each of four areas, the four areas being formed by dividing a cross section of a vacuum duct 1 extending perpendicularly to a direction in which a charged particle beam travels by a symmetrical surface having each of both magnetic poles of the dipole magnet defined as a mirror image and a plane which extends perpendicularly to the symmetrical surface and through which a center of gravity of the charged particle beam passes.

Abstract: Disclosed herein are provided an arrangement of devices suitable to downsize a synchrotron, a synchrotron using such an arrangement, and a particle therapy system using the synchrotron. In the synchrotron, a plurality of deflection magnets and a single defocusing quadrupole magnet are arranged between a first extraction deflector and a second extraction deflector. The defocusing quadrupole magnet is arranged between deflection magnets among the plurality of deflection magnets, a focusing quadrupole magnet is arranged on the side of an inlet of the first extraction deflector, and a focusing quadrupole magnet is arranged on the side of an outlet of the second extraction deflector.

Abstract: Disclosed herein are provided an arrangement of devices suitable to downsize a synchrotron, a synchrotron using such an arrangement, and a particle therapy system using the synchrotron. In the synchrotron, a plurality of deflection magnets and a single defocusing quadrupole magnet are arranged between a first extraction deflector and a second extraction deflector. The defocusing quadrupole magnet is arranged between deflection magnets among the plurality of deflection magnets, a focusing quadrupole magnet is arranged on the side of an inlet of the first extraction deflector, and a focusing quadrupole magnet is arranged on the side of an outlet of the second extraction deflector.

Abstract: To provide a magnetic field control apparatus capable of reducing a width of a correcting plate. The magnetic field control apparatus includes a conductive vacuum duct 1 disposed between dipole magnet magnetic poles 3 and a conductive correcting plate 2. The correcting plate 2 is formed of a material having an electric conductivity higher than that of the vacuum duct 1. A plurality of conductive correcting plates 2 are disposed in each of four areas, the four areas being formed by dividing a cross section of a vacuum duct 1 extending perpendicularly to a direction in which a charged particle beam travels by a symmetrical surface having each of both magnetic poles of the dipole magnet defined as a mirror image and a plane which extends perpendicularly to the symmetrical surface and through which a center of gravity of the charged particle beam passes.