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ALS-U Timeline & Facility Impacts

In September 2016 DOE initiated the ALS-U project by approving its “mission need” and assigning it critical decision (CD)-0 status, the first milestone in making the upgrade a reality. Over the next several years, the project team completed engineering and design work, and the project was baselined. In November 2022, the project received approval to start construction, known as CD-3. This page outlines the remaining steps and anticipated impacts on the user community.

ALS-U Project Schedule Update

The ALS-U project is reviewing and revising its schedule. As of now, the planning assumption is that the start of dark time will be delayed by one year, to the summer of 2027. Beam operations are expected to continue until then. Please check this page for updates in 2025.

A series of images lined up next to each other. Photos (left to right) include a person holding a tube, two people looking at a metal beamline, a person in hard hat maneuvering equipment, two people in lab with safety goggles on and two people with gloves on.
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Before the Dark Time 

In summer 2023, installation of the accumulator ring magnets began. Construction of this “damping” ring is ongoing during regular shorter and longer ALS shutdowns. A special review will be conducted at least six months before the dark time to determine the project’s readiness. If the project is ready, it will commit to the dark time start date. The ALS will continue to provide as much beam as possible to users until the dark time begins.

What to Expect

Shutdowns

  • Increased down time is required to install the accumulator ring and to complete as much work as possible for the storage-ring seismic retrofit and radiation shielding upgrade before the dark time.
  • The schedule for long shutdowns to accomplish this work is likely to continue to be two ~13-week shutdowns per year, beginning in January and July. 
  • Regular shorter maintenance shutdowns and accelerator physics shifts will continue as usual. They are critical to maintain reliable operation of the current ALS, and accelerator physics time helps minimize the ALS-U commissioning risk.
  • See the Operating Schedule for more information.

Beamlines

  • Most beamlines will operate until the dark time begins.
  • Beamlines 8.0.1 and 10.0.1 will be decommissioned approximately six months and two months before the dark time, respectively, to make way for the new feature insertion-device beamlines that will be installed at these locations.
  • A few beamlines will need to be turned off a few weeks or months early to clear spaces designated as major pathways for storage-ring equipment removal and replacement and for other prep work. See the Post-ALS-U Beamline Status Table on this page for more information.
  • Bend-magnet beamline infrastructure in Sectors 1, 2, 3, 7, and 8 will be affected by the removal and installation of the accelerator. Racks will need to be removed and some areas cleared one to two months before the dark time. Intermittent impacts (which began in 2023 and will continue through the dark time) include the temporary relocation of some beamline equipment protection systems and temporary clearing of some beamline areas so that the shield wall seismic retrofit can begin.

During the Dark Time 

The facility dark time, the timeframe without any user operations, is when the present-day ALS storage ring will be removed and a new ring built and commissioned in its place. Storage-ring removal and installation is expected to take approximately nine months, followed by storage-ring commissioning. Bend-magnet beamlines will be moved and some beamline upgrades will be performed, and beamline commissioning will begin.

The ALS-U project is currently conducting a thorough review and revision of its schedule. Until more definitive information is known in 2025, the planning assumption is that the start of dark time will be delayed one year, to summer 2027. See details in this announcement.

What to Expect

  • The accelerator will be turned off until storage-ring commissioning begins; there will be no user operations on the experimental floor.
  • The experimental floor will be a construction zone with very limited access.
  • Additional construction impacts include changes to pedestrian and vehicular traffic routes, some additional noise and vibration, and power and cooling-water outages of a few days each at the beginning and end of the dark time.

Transition to Operations

The dark time will be followed by a six-month transition to operations period, when beamlines will be brought back online and accelerator commissioning will continue. The ALS-U project team is currently working to determine the order in which beamlines will be turned on. 

What to Expect

  • Operations during this period will likely be characterized by low current, beam instabilities, and beam interruptions. Early experiments may therefore be most appropriately carried out by beamline scientists. Collaborative access with users may be possible, but the ALS will not return to regular user operations during this phase.
  • Beamlines that have returned to operation may require further commissioning past the transition to operations period or may need to wait for the storage-ring current to reach a certain value at which experiments become feasible for full user operations to resume on that particular beamline.
  • Additional time past the transition to operations period will be needed to return all beamlines to operation.

The ALS-U project will end when CD-4 is approved upon demonstration of the project’s threshold key performance parameters (KPPs). The current schedule provides a broad range of possible project completion dates (March 2027–September 2029) to account for possible delays in the start of the dark time or other circumstances that delay achievement of the threshold KPPs.

ALS-U project key performance parameters (KPPs). Threshold KPPs must be achieved before the project can end. Objective KPPs are the desired operational goal.

Ramp-Up to Full Operations

Accelerator development and beamline commissioning will continue. Any beamlines not yet returned to operations will be brought online.

What to Expect

  • Available beamtime will increase as the accelerator current ramps up and beam instabilities are mitigated and interruptions decrease.
  • Another six months (one year past the end of the dark time) or more may be needed to get to a full steady state of user operations. It could take longer to reach the target current of 500 mA.

User Proposal Expectations

General User Proposals (GUPs) will become inactive and end at the start of the dark time. New proposals will need to be submitted as the upgraded facility comes back online. Approved Programs (APs) will be paused at the dark time and restart when collaborative access becomes available at the relevant beamline.

  • Before the dark time: Beginning two years before the dark time, new proposals will begin to be active for less than two years. The last AP call is currently expected to be in January 2026, the last GUP call is currently expected to be in March 2026, and the last beamtime requests on active proposals will be taken in September 2026. The ALS-U project is currently revising its schedule, so these dates may shift. We anticipate more information in 2025. 
  • During the dark time: The facility will be closed for construction; there will be no beamline operations.
  • Transition to operations: Beamlines will be in commissioning. There will be no general user operations, but collaborative access may be possible.
  • Ramp-up to full operations: RAPIDD proposals will be phased in as beamlines become available. Formal proposal calls will resume when beamlines are fully operational.

Feedback and Questions

Feedback and questions are welcomed.