Model studies on separated sectored cyclotrons

A set of general equations for optimizing the sector shapes in isochronous cyclotrons, presented earlier are also found to be valid for separated sectored cyclotrons in the limit when the valley field tends to zero. These hard edge equations have been evaluated experimentally for the case of separated sectored cyclotrons. One out of eight periods of a separated sectored electron cyclotron magnet has been built. The magnetic field of the spiral sectored magnet was mapped in the median plane using a polar jig. The equilibrium orbit properties in the measured field were computed using the code ORBIT. These measured orbit properties are compared with those expected with the hard edge equations. Experimental methods developed for the above studies are described. Some special techniques necessary for orbit analysis in this case are also discussed. (author)