Application of Wigglers to Quasi-isochronous Transport Systems

The transition energy of a circular machine based on standard FODO lattices depends on the horizontal optics of the cell and, therefore, on the average radius of the machine. This property imposes tight constraints on the design of isochronous machines that are frequently considered for applications such as electron and proton accumulators ormunrs.Th epriceto be paid to satisfy the isochronous condition is to have a dispersion function with very large peak values aloneh machine circumference. In this paper, a number of optical modules, which we call wigglers, in analogy with the devices used in electron machines, are presented that overcome such difficulties. A careful analysis of their properties is carried out. Using these new concepts, it is shown how to design isochronous machines for which the machine radius and the transition energy are independent of each other, while keeping the value of the dispersion function under control.