APS Upgrade |  GSECARS Upgrade Plans

Images of Xray Microprobe Data

APS Upgrade

The APS is planning an upgrade of the storage ring to a Multi-Bend Achromat (MBA) lattice (APS-U) which will result in a dramatic improvement in the brightness of both the undulator and bending magnets at the APS. This upgrade will reduce the horizontal emittance of the machine by a factor of 40, which means a much smaller electron beam source size and divergence. This will greatly improve our ability to focus the x-ray beam into a small spot with high flux, and so will be a huge benefit to the microprobe and diamond anvil cell programs at GSECARS. The storage ring energy will be reduced from 7 to 6 GeV, so the APS-U project will provide new optimized undulators to all the beamlines.

The start of the year-long installation period was pushed back to April 17, 2023. This is a delay of 10 months from the original start date, and the delay is due to the COVID-19 pandemic and its impacts on the project. The pandemic has caused issues with supplying components and parts to Argonne for the project, and with most of the laboratory’s staff working remotely during the limited operations phase, it is also delaying important work that needs to be done on site.

Pushing the start of the installation period back means that users will get a full year of APS operations in 2022, and at least an abbreviated run at the start of 2023. The storage ring installation period is still planned to only last one year during which time the APS will be shut down and inaccessible to users. The upgraded APS is scheduled to restart with the commissioning of beamlines in April 2024, before a similar upgrade at the Advanced Light Source (ALS) at Lawrence Berkeley National Laboratory is scheduled to begin, in 2025.

One of the challenges that GSECARS, and all APS beamlines will face is having optics, sample positioning stability, and detector readout speeds that will allow taking maximal advantage of this increase in brightness, and the consequently smaller focus spot and/or higher count rate.

To take maximum advantage of the improved source, GSECARS plans to upgrade our focusing optics and detectors.  The APS-U project itself will fund a number of optics upgrades for GSECARS undulator beamlines through the APS-U Enhancement program. The bending magnet beamlines will need to be shifted slightly to accommodate the new source position.

Up-to-date information on the APS Upgrade project can be found at http://www.aps.anl.gov/APS-Upgrade/.



Mark Rivers

Director, Center for Advanced Radiation Sources (CARS)
Co-Director GSECARS
Beamline Scientist
University of Chicago Research Professor
(630) 252-0422

Peter Eng

Beamline Scientist
University of Chicago Research Professor
(630) 252-0424