An example particle accelerator includes the following: a voltage source to provide a radio frequency (RF) voltage to a cavity to accelerate particles from a plasma column, where the cavity has a magnetic field causing particles accelerated from the plasma column to move orbitally within the cavity; an extraction channel to receive the particles accelerated from the plasma column and to output the received particles from the cavity; and a regenerator to provide a magnetic field bump within the cavity to thereby change successive orbits of the particles accelerated from the plasma column so that, eventually, particles output to the extraction channel. The magnetic field is at least 6 Tesla and the magnetic field bump is at most 2 Tesla.

An example particle accelerator includes the following: a voltage source to provide a radio frequency (RF) voltage to a cavity to accelerate particles from a plasma column, where the cavity has a magnetic field causing particles accelerated from the plasma column to move orbitally within the cavity; an extraction channel to receive the particles accelerated from the plasma column and to output the received particles from the cavity; and a regenerator to provide a magnetic field bump within the cavity to thereby change successive orbits of the particles accelerated from the plasma column so that, eventually, particles output to the extraction channel. The magnetic field is at least 6 Tesla and the magnetic field bump is at most 2 Tesla.

A charge stripping method includes irradiating a charge stripping film with an ion beam. The charge stripping film includes a single layer body of a graphitic film having a carbon component of at least 96 at % and a thermal conductivity in a film surface direction at 25 C. of at least 800 W/mK, or a laminated body of the graphitic film. The charge stripping film has a thickness of not less than 100 nm and less than 10 m, a tensile strength in a film surface direction of at least 5 MPa, a coefficient of thermal expansion in the film surface direction of not more than 110.sup.5/K, and an area of at least 4 cm.sup.2.

A charge stripping method includes irradiating a charge stripping film with an ion beam. The charge stripping film includes a single layer body of a graphitic film having a carbon component of at least 96 at % and a thermal conductivity in a film surface direction at 25 C. of at least 800 W/mK, or a laminated body of the graphitic film. The charge stripping film has a thickness of not less than 100 nm and less than 10 m, a tensile strength in a film surface direction of at least 5 MPa, a coefficient of thermal expansion in the film surface direction of not more than 110.sup.5/K, and an area of at least 4 cm.sup.2.

A particle therapy system in which the efficiency of extracting a beam from a synchrotron can be improved and time required for therapy can be shortened is provided. The synchrotron 10 of the particle therapy system 100 extracts a charged particle beam, which circulates in the synchrotron 10, out of the synchrotron 10 by means of a slow extraction method using the resonance of a betatron oscillation, and magnetic poles 73 included in a bending magnet 12 of the synchrotron 10 have a SIM structure that generates a magnetic field distribution that makes the horizontal tune of the charged particle more closely approach a resonant line used in the slow extraction method as the amplitude of the horizontal betatron oscillation of a charged particle included in the charged particle beam becomes larger.

A particle therapy system in which the efficiency of extracting a beam from a synchrotron can be improved and time required for therapy can be shortened is provided. The synchrotron 10 of the particle therapy system 100 extracts a charged particle beam, which circulates in the synchrotron 10, out of the synchrotron 10 by means of a slow extraction method using the resonance of a betatron oscillation, and magnetic poles 73 included in a bending magnet 12 of the synchrotron 10 have a SIM structure that generates a magnetic field distribution that makes the horizontal tune of the charged particle more closely approach a resonant line used in the slow extraction method as the amplitude of the horizontal betatron oscillation of a charged particle included in the charged particle beam becomes larger.

The present disclosure relates to a magnet pole for an isochronous sector-focused cyclotron having hill and valley sectors alternatively distributed around a central axis, Z, each hill sector having an upper surface bounded by four edges: an upper peripheral edge, an upper central edge, a first and a second upper lateral edges, and a peripheral surface extending from the upper peripheral edge to a lower peripheral line. The upper peripheral edge of at least one hill sector may further include a concave portion with respect to the central axis defining a recess extending at least partially over a portion of the peripheral surface of the corresponding hill sector.

The present disclosure relates to a magnet pole for an isochronous sector-focused cyclotron having hill and valley sectors alternatively distributed around a central axis, Z, each hill sector having an upper surface bounded by four edges: an upper peripheral edge, an upper central edge, a first and a second upper lateral edges, and a peripheral surface extending from the upper peripheral edge to a lower peripheral line. The upper peripheral edge of at least one hill sector may further include a concave portion with respect to the central axis defining a recess extending at least partially over a portion of the peripheral surface of the corresponding hill sector.

System includes a particle accelerator configured to direct a particle beam of charged particles along a designated path. The system also includes an extraction device positioned downstream from the particle accelerator. The extraction device includes a stripper foil and a foil holder that holds the stripper foil. The foil holder is configured to position the stripper foil across the designated path of the particle beam such that the particle beam is incident thereon. The stripper foil is configured to remove electrons from the charged particles, wherein the stripper foil includes a backing layer and a conductive layer stacked with respect to one another. The backing layer includes synthetic diamond.

System includes a particle accelerator configured to direct a particle beam of charged particles along a designated path. The system also includes an extraction device positioned downstream from the particle accelerator. The extraction device includes a stripper foil and a foil holder that holds the stripper foil. The foil holder is configured to position the stripper foil across the designated path of the particle beam such that the particle beam is incident thereon. The stripper foil is configured to remove electrons from the charged particles, wherein the stripper foil includes a backing layer and a conductive layer stacked with respect to one another. The backing layer includes synthetic diamond.