A particle beam to treat malignant tissue is delivered to a patient by a gantry. The gantry includes a plurality of small magnets sequentially arranged along a beam tube to transfer the particle beam with strong focusing and a small dispersion function, whereby a beam size is very small, allowing for the small magnet size. Magnets arranged along the beam tube uses combined function magnets where the magnetic field is a combination of a bending dipole field with a focusing or defocusing quadrupole field. A triplet set of combined function magnets defines the beam size at the patient. A scanning system of magnets arranged along the beam tube after the bending system delivers the particle beam in a direction normal to the patient, to minimize healthy skin and tissue exposure to the particle beam.
STATEMENT OF GOVERNMENT LICENSE RIGHTS
This invention was made with Government support under contract number DE-AC02-98CH10886, awarded by the U.S. Department of Energy. The Government has certain rights in the invention.