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At the Heavy Ion Medical Accelerator in Chiba (HIMAC), more than 8000 patients have been successfully treated by carbon ion beams since 1994. The successful results of treatments have led us to construct a new treatment facility equipped with a 3-D pencil beam scanning irradiation system. For the implementation of this irradiation technique, we developed a fast scanning magnet and its power supply, which are required to have field ramp rate of more than 250 T/s. The scanning magnets set at the entrance of the irradiation system are two dipole magnets to scan the beam in both horizontal and vertical directions and used to form the irradiation field to be tumor shape. Before the installation, performance test including both static and dynamic field measurement was carried out. Severe delay of the field and temperature rise were not observed as expected. Measured field ramp rate reached up to 300 T/s. After the installation, we verified the accuracy and stability of the scanned ion beam through the commissioning with the beam. As a successful result of the commissioning, treatment using the new scanning system was started in 2011. [ABSTRACT FROM PUBLISHER]

Combined-function superconducting magnets are designed for a heavy-ion rotating gantry. The superconducting coils of these magnets have a surface winding coil structure. To minimize sagitta, the superconducting magnets as well as their coils have a curved shape. Ten superconducting magnets are installed on the rotating gantry. With the superconducting magnets, the rotating gantry can transport carbon ions having 430 MeV/u to a patient with irradiation angles of over \pm180 degrees, and is further capable of performing three-dimensional raster-scanning irradiation. Since the superconducting magnets would be rotated by \pm180 degrees, compact cryocoolers are employed for cooling of the superconducting coil. Because the coil has quadrupole and dipole layers, the superconducting magnets can provide both quadrupole and dipole magnetic field. Using the combined-function superconducting magnets, we can design a compact rotating gantry, while keeping a large scan size at the isocenter; the length and the radius of the gantry would be approximately 13 and 5.5 m, respectively, which are comparable to those for the existing proton gantries. In this paper, we report the design of the superconducting magnets as well as results of some tests. [ABSTRACT FROM PUBLISHER]