New optical configurations making use of circular faces between magnetic sectors

In electron or ion-beam optics, a new family of optical configurations makes use of circular separations between magnetic sectors. A short general analytical description is followed by the analysis of all three-sector systems, of a subclass of five-sector systems and of a particular case nine-sector system. They are useful for beam deflection, for pulse length compression or for beam energy analysis. Specific examples given include a three-sector 2700 beam deflection system used in medical linacs, a five-sector 3600 beam rotation electromagnet used at the Euratom BCMN for pulse length compression and a compact nine-sector 7200 beam rotation electromagnet design. (orig.)