The Advanced Photon Source (APS) is in the midst of a major facility upgrade consisting of a new electron storage ring (SR) and many new insertion devices (IDs) which will provide x-ray photon beams to a new suite of experimental end stations. Included among the new IDs are four 4.8-meter superconducting undulator (SCU) cryostats, each containing two 1.9-meter planar undulator magnets operating at 4.2 K in either an in-line or canted configuration. We describe a new, compact cryocooler-based cryostat design which supports the magnets and associated subsystems and also fits the space constraints of the SR ID straight sections. The design is an evolution of earlier single-magnet 2-meter cryostats, retaining some subsystem commonality while incorporating lessons learned and several features unique to the challenge of supporting two independently operable undulator magnets in a single device.
* Work supported by the U.S. Department of Energy, Office of Science under Contract No. DE-AC02-06CH11357.