Abstract: A compact, cold, superconducting isochronous cyclotron can include at least two superconducting coils on opposite sides of a median acceleration plane. A magnetic yoke surrounds the coils and a portion of a beam chamber in which ions are accelerated. A cryogenic refrigerator is thermally coupled both with the superconducting coils and with the magnetic yoke. The superconducting isochronous cyclotron also includes sector pole tips that provide strong focusing; the sector pole tips can have a spiral configuration and can be formed of a rare earth magnet. The sector pole tips can also be separated from the rest of the yoke by a non-magnetic material. In other embodiments, the sector pole tips can include a superconducting material. The spiral pole tips can also include cut-outs on a back side of the sector pole tips remote from the median acceleration plane.

Abstract: The present invention provides a linear accelerator in which a rotatable conductive vane is employed to vary the electromagnetic coupling between adjacent accelerating cells. The vane is sealed off from the rest of the linear accelerator by an insulating partition, so the pressure around the vane can be higher than in the rest of the accelerator. This greatly simplifies the mechanisms which may be used to control the rotation of the vane, allowing a higher bakeout temperature in manufacture and a higher rate of rotation in use.

Abstract: A compact, cold, weak-focusing superconducting cyclotron can include at least two superconducting coils on opposite sides of a median acceleration plane. A magnetic yoke surrounds the coils and contains an acceleration chamber. The magnetic yoke is in thermal contact with the superconducting coils, and the median acceleration plane extends through the acceleration chamber. A cryogenic refrigerator is thermally coupled both with the superconducting coils and with the magnetic yoke.