Design of the e-beam transport line for the AFEL

The Advanced Free-Electron Laser (AFEL) currently construction at Los Alamos National Laboratory is a compact high-performance free- electron laser (FE). The design of the AFEL integrates our most advanced accelerator and wiggler components. The 1.2-m-long accelerator produces a high-brightness electron-beam (e-beam) of 200- to 300-A peak current with an energy of 20 MeV. The beamline incorporates variable permanent-magnet quadrupoles and dipoles for electron beam transport. The AFEL will ultimately use 10- to 20-cm-long slotted-tube pulsed microwigglers having a period of 3-mm to 1-cm. In this paper, we shall present the design of the e-beam transport line and discuss the various design considerations involved. 7 refs., 5 figs., 3 tabs.