FETS-VFFA Cell using Contour-Based Magnets

Abstract

A pure-conductor winding arrangement has been found that approximates the optics of the design given in (Figure 1). The tunes are not the same but are reasonably flat and exist through the entire 3–12 MeV energy range, so could conceivably be fine-tuned using the vertical winding density function in the next section. The lattice consists of two magnets: a reverse bending Bd magnet followed by a normal bending Bf magnet. These magnets are both sectors whose midpoints are displaced with respect to the midpoints of the sides of a 20-sided polygon with side length 1.25 m. The ring is said to have 10 cells (2 polygon sides per cell) that are 2.5 m long. The displacements are 17 cm inwards for Bd and 17 cm outwards for Bf.