High frequency focusing-accelerating structures

Optimizing coupling in biperiodic accelerating structures

“…The difference in coupling cell RF losses accounts for at least half of the shunt impedance difference. Substituting Table 2 Our previous rectangular structure results [5,7] suffered from a modest coupling which, when increased, caused a significant shunt impedance decrease. In our new structure, seen in Fig.…”

“…Focusing gradients, GX,?, determine the cavity focusing strength amplitude (i.e., the inverse focal length times the longitudinal particle momentum), SX,? [7], as _ n (7) where h is the operating mode wave length and E,, is the lst harmonic electric field amplitude. For circular beam holes, the gradients are of opposite sign of those for 10 x 20 mmz rectangular beam slots.…”

“…With symmetry in the two transverse directions, this rectangular structure has quadrupole-like focusing, and by modifying the beam holes, its focusing strength can be varied over a wide range [7]. High-current continuous wave electron linear accelerators with rectangular accelerating structures would allow larger currents to be accelerated [SI but the resulting high beam and heat loading would require high coupling to maintain uniform accelerating field distributions.…”

A novel racetrack microtron accelerating structure

“…We solved this problem by using a rectangular accelerating structure with rectangular vertically extended beam slots. This structure also produces high frequency horizontal focusing, which we use to simplify the RTM construction and operation [1,2]. We found the RCBS structure dimensions with optimal electrodynamics characteristics, seen in Fig.…”