Beam scanning system for a heavy ion gantry

Abstract

The present invention relates to a scanning System for a heavy ion gantry comprising a scanner magnet (1-2; 3-4) for a high energy ion beam used in a heavy ion cancer therapy facility having a maximal bending angle (α) of about 1.5. degree; a curvature radius of about 22 m; a path length of about 0.6 m and a gap height (h) and a gap width (w) in the range of 120 mm to 150 mm. Further each scanner magnet (1-2, 3-4 ) comprises one glued yoke element made of steel plates having a thickness of up to 0.3 mm and being alloyed with up to 2% silicon. This yoke element has a width in the range of 300 mm to 400 mm, a height in the range of 200 mm to 250 mm and a length in the range of 500 to 600 mm. A coil for each scanner magnet (1-2; 3-4) has a number of windings in the range of 50 to 70. Further the system (11) comprises a 90 degree dipole (6) positioned downstream of said scanner magnets (1-2; 3-4) having an aperture adapted to the scanning area, and enclosing a yoke element with gaps to increase the homogeneity of the electric field. Additionally the system encloses beam diagnostic plate type detectors (7) stapled downstream of said 90 degree bending magnet (6).

Dependencies are inferred from the claim text.