The Advanced Photon Source
a U.S. Department of Energy Office of Science User Facility

APS Upgrade Update: April 2024


I don't think it's an exaggeration to say we've been anticipating this moment since April 2023. Almost exactly a year ago, we shut down the Advanced Photon Source (APS) to begin removing the original electron storage ring and installing the new one we were still in the process of building. In this past year, our team accomplished a remarkable amount.

Late last month, we held a very successful Accelerator Readiness Review for the new APS storage ring, now fully installed. The reviewers — a team of experts from other U.S. Department of Energy (DOE) national labs — had complementary words to say about our efforts and confirmed we only had a few pre-start conditions to meet before starting up. Earlier this month, with those conditions met, we received approval from the DOE Argonne Site Office to proceed with commissioning the new machine.

Commissioning began on April 10, 2024, and just a few days later we had our first electrons circulating the ring. On April 20 we achieved the first stored beam in the new ring. We completed our first round of radiation shielding verifications and are on the way to fully demonstrating the first use of swap-out injection in a storage-ring-based light source. These are all significant milestones on the road to delivering the first photons to a beamline, a goal that is closer now than ever.

As our tremendous team of accelerator physicists continues to bring the storage ring up to speed, we're making good strides in bringing beamlines back into operation. As I've mentioned, there are multiple steps involved in commissioning each beamline, and the process of bringing them all online will continue for the next year. In future updates, we'll be presenting more information on the status of the beamlines, and the steps for the beamlines next in the queue.

That information will also be on the APS Upgrade web page, along with the latest information on the progress of the storage ring. You can also see our latest installments of the People of the APS Upgrade profile series, spotlighting mechanical engineering specialist Grace Avellar.

The mood is upbeat here at the APS, but we still have a lot of work to do (and do safely). I'll keep it short this month so we can get back to it. This is a world-leading, one-of-a-kind, complex machine we have built, and it will take some time to characterize and understand how to run it well. We will execute every step safely. The first general user run on the upgraded APS is scheduled for the fall, and we’ll be gradually ramping up power in the storage ring until we reach the machine's full capacity. (The new Universal Proposal System is accessible here.)

For those of you attending the APS/CNM Users Meeting, May 6–10, I will see you at the APS Upgrade Q&A session. (Submit your questions to Until the next Upgrade Update in May, stay safe.

Jim Kerby
Director, APS Upgrade Project

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