General design of the layout for new undulator-only beamline front ends

A great majority of the Advanced Photon Source (APS) users have chosen an undulator as the only source for their insertion device beamline. Compared with a wiggler source, the undulator source has a much smaller horizontal divergence, providing us with an opportunity to optimize the beamline front-end design further. In this paper, the particular designs and specifications, as well as the optical and bremsstrahlung ray-tracing analysis of the new APS front ends for undulator-only operation are presented.