The present disclosure relates to compact isochronous sector-focused cyclotrons having reduced dimensions and weight compared with state of the art cyclotrons of same energies. In one implementation, a cyclotron may include two pole magnets facing each other in a chamber defined by a yoke having base plates and flux return yokes forming a lateral wall of the chamber. The magnet poles may include between three and eight hill sectors alternating with a same number of valley sectors distributed about a central axis. The lip of the abyssal opening may be positioned at a distance from the corresponding valley peripheral edge. The flux return yoke may have a thickness in the portions facing valley sectors, such that the ratio of the product of the distance times the thickness to the square of the distance of the peripheral edge to the central axis is less than 5%.

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.

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. The upper surface of at least one hill sector may further include: a recess extending over a length between a proximal end and a distal end along a longitudinal axis intersecting the upper peripheral edge and the upper central edge. The recess may be separate from the first and second upper lateral edges over at least 80% of its length, and a pole insert having a geometry fitting in the recess may be positioned in, and reversibly coupled to the recess.

A non-scaling fixed field alternating gradient accelerator includes a racetrack shape including a first straight section connected to a first arc section, the first arc section connected to a second straight section, the second straight section connected to a second arc section, and the second arc section connected to the first straight section; an matching cells configured to match particle orbits between the first straight section, the first arc section, the second straight section, and the second arc section. The accelerator includes the matching cells and an associated matching procedure enabling the particle orbits at varying energies between an arc section and a straight section in the racetrack shape.

A non-scaling fixed field alternating gradient accelerator includes a racetrack shape including a first straight section connected to a first arc section, the first arc section connected to a second straight section, the second straight section connected to a second arc section, and the second arc section connected to the first straight section; an matching cells configured to match particle orbits between the first straight section, the first arc section, the second straight section, and the second arc section. The accelerator includes the matching cells and an associated matching procedure enabling the particle orbits at varying energies between an arc section and a straight section in the racetrack shape.

A magnetic orbital angular momentum beam accelerator will accelerate charged particles, electrons or ions, from rest in zero or low magnetic field into a high magnetic field regions with high kinetic energies in the form of magnetic orbital angular momentum. For example, a beam injector that accelerates electrons or ions into 1T magnetic fields with tens of keV kinetic energies transverse to the magnetic fields can be used to heat magnetically confined plasmas, to inject an initial energetic plasma component with high magnetic orbital angular momentum and to produce highly transverse particle momenta to the magnetic field for electron or ion beam lithography.

A magnetic orbital angular momentum beam accelerator will accelerate charged particles, electrons or ions, from rest in zero or low magnetic field into a high magnetic field regions with high kinetic energies in the form of magnetic orbital angular momentum. For example, a beam injector that accelerates electrons or ions into 1T magnetic fields with tens of keV kinetic energies transverse to the magnetic fields can be used to heat magnetically confined plasmas, to inject an initial energetic plasma component with high magnetic orbital angular momentum and to produce highly transverse particle momenta to the magnetic field for electron or ion beam lithography.