A design for a wide-aperture 90/spl deg/ bending magnet for heavy-ion cancer therapy

A description of a wide-aperture 90-degree bending magnet is presented. This magnet was designed as a part of a beam delivery system of the heavy-ion therapy facility developed in GSI, Darmstadt, Germany. A concept of the "almost window frame" magnet with the air slots in a yoke ensures a homogeneous field (/spl Delta/B/B