A magnet device that includes upper and lower disk-shaped return yokes, a pair of upper magnetic pole and lower magnetic pole respectively fixed to a disk-shaped surface of the upper return yoke and a disk-shaped surface of the lower return yoke, in which a space to circulate and accelerate an ion beam is formed between the upper magnetic pole and the lower magnetic pole. The upper magnetic pole and the lower magnetic pole have a plurality of concave and convex parts along a track along which the ion beam circulates, are plane-symmetrical with respect to a horizontal symmetry plane formed by the track along which an ion beam circulates, and are plane-symmetrical to one of the vertical planes vertical to the horizontal symmetry plane. Also, the magnetic pole intervals between the concave parts of the upper magnetic pole and the lower magnetic pole are different from each other.

Disclosed is a method of utilizing deuterons (nuclear particles consisting of a proton and a neutron) for charged particle radiotherapy. Compared with proton therapy, at their maximum treatment depth of 66 mm, 125 MeV deuterons possess 82-85% less beam straggling than protons. This difference enables better protection of radiosensitive critical tissues that may be in contact with a tumor. Alternatively, it enables higher doses to be delivered to the tumor, resulting in better tumor control. The implementation of deuteron therapy interchangeably alongside proton therapy requires minor modifications at modest cost to many existing proton therapy systems and provides a clinically useful hybrid particle therapy facility. A free-standing deuteron therapy facility that employs only deuterons is also described.

A proton therapy system based on a compact superconducting cyclotron, including: a superconducting cyclotron system, an energy selection system, a beam transport system, a fixed therapy room subsystem and a rotating frame therapy subsystem; a fixed-energy proton beam extracted from a superconducting cyclotron of the superconducting cyclotron system is adjusted into a continuous and adjustable proton beam of 70 MeV to 200 MeV by the energy selection system, thus realizing a longitudinal adjustment for a proton range during treating a tumor, and the continuous and adjustable proton beam is respectively transmitted to the fixed therapy room subsystem and the rotating frame therapy subsystem by the beam transport system. The cooperative control of the superconducting cyclotron system, the energy selection system, the beam transport system and the therapy head realizes the transverse expansion of proton beams, thus realizing intensity modulated radiation therapy for the tumor.

A cryogenic magnet structure includes at least two superconducting coils that are substantially symmetric about a central axis and on opposite sides of a median plane. At least one cryostat contains the superconducting coils; and a magnetic yoke surrounds the superconducting coils and contains at least a portion of a chamber, wherein the median plane extends through the chamber. At least one integral maintenance boot assembly is in thermal contact with the superconducting coils and is configured to preserve a sealed vacuum in the cryostat; and a cryogenic refrigerator is in thermal contact with the maintenance boot assembly and is configured to cool the superconducting coils below their critical superconducting temperatures and is configured for removal from thermal contact with the integral maintenance boot assembly without breaking the sealed vacuum in the cryostat.

A gantry-less particle therapy system is provided. Charged particles are extracted from an ion source and accelerated in a beam transport system having an annular portion extending in a first plane and that circumscribes a volume, an arcuate portion extending in a second plane, and a transition portion that connects the annular portion and the arcuate portion. The arcuate portion terminates at a beam nozzle extending radially inward from the annular portion to deliver an ion beam to a treatment area contained in the volume circumscribed by the annular portion.

A cryogenic magnet structure includes at least two superconducting coils that are substantially symmetric about a central axis and on opposite sides of a median plane. At least one cryostat contains the superconducting coils; and a magnetic yoke surrounds the superconducting coils and contains at least a portion of a chamber, wherein the median plane extends through the chamber. At least one integral maintenance boot assembly is in thermal contact with the superconducting coils and is configured to preserve a sealed vacuum in the cryostat; and a cryogenic refrigerator is in thermal contact with the maintenance boot assembly and is configured to cool the superconducting coils below their critical superconducting temperatures and is configured for removal from thermal contact with the integral maintenance boot assembly without breaking the sealed vacuum in the cryostat.

The present invention provides a particle projection spatial imaging system, comprising a particle source for generating and accelerating a particle beam, a deflection coil set for deflecting the particle beam into a chronologically deployed dynamic 3D particle array, an exciting coil set for generating a magnetic field, and a scan control mechanism for controlling the particle source, the deflection coil set, and the particle exciting coil set. The particle projection spatial imaging system set forth by the present invention generates a 3D spatial image by generating and accelerating a particle beam by providing a particle source, deflecting the particle beam by using a deflection coil set to form a dynamic 3D particle array, and exciting particle bunches at corresponding pixel points in the array in a time-division manner by a particle exciting coil set to cause them to generate a radiation effect, and this particle projection spatial imaging system does not rely on a solid display medium, and can operate in the air and in vacuum. A 3D dynamic image can be generated by refreshing the scan control mechanism.

A magnet device that includes upper and lower disk-shaped return yokes, a pair of upper magnetic pole and lower magnetic pole respectively fixed to a disk-shaped surface of the upper return yoke and a disk-shaped surface of the lower return yoke, in which a space to circulate and accelerate an ion beam is formed between the upper magnetic pole and the lower magnetic pole. The upper magnetic pole and the lower magnetic pole have a plurality of concave and convex parts along a track along which the ion beam circulates, are plane-symmetrical with respect to a horizontal symmetry plane formed by the track along which an ion beam circulates, and are plane-symmetrical to one of the vertical planes vertical to the horizontal symmetry plane. Also, the magnetic pole intervals between the concave parts of the upper magnetic pole and the lower magnetic pole are different from each other.

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.

To provide an accelerator that easily provides a space for placing equipment incorporated into an accelerator magnet, and that has a dense region with small turn separations of beams and a sparse region with large turn separations of the beams in different positions in the beam orbit direction. A pair of magnetic poles (8, 9) has a depression structure of a plurality of depression and projection structures, in a position intersecting with a vertical plane (3). A boundary surface (41, 44, 45, 48) between the depression structure (21, 23) placed in a position intersecting with the vertical plane (3) and a projection structure (31, 32, 33, 34) adjacent to the depression structure has unanimously either a projection shape or a depression shape with respect to the vertical plane (3).