The upgrade of the Advanced Photon Source (APS), a U.S. Department of Energy Office of Science user facility, reached a major milestone in December 2023. The final modules of the newly upgraded electron storage ring at the heart of the APS have now been installed, a significant step toward the completion of the removal and installation phase of the project that began in April 2023.

The new storage ring consists of 200 magnet modules arranged in various configurations. Each module was assembled to exacting specifications and then carefully transported from an offsite warehouse facility to the APS for installation. Before the final doublet L-bend multiplet (DLM) module was moved and installed, about 100 members of the APS Upgrade team signed it, carrying on a tradition from the construction of the original APS nearly three decades ago. 

The next step of the process, already in progress, is to test each of the systems on every magnet module and ensure they work (and work together). We will then conduct an accelerator readiness review that will authorize us to begin commissioning the new machine and prepare for operations.