The Advanced Photon Source (APS) has been one of the most productive X-ray light sources in the world for more than 25 years. In order to provide new capabilities to scientific community, a major, $815 million upgrade to the facility is planned to start in April 2023 (APS-U). As part of APS-U, the current electron storage ring will be replaced with a state-of-the-art multi-bend achromat lattice. The upgrade will result in:
- Electron beam current increased by a factor of 2 (200mA vs current 100mA)
- Electron beam emittance (beam size x beam divergence) reduced by a factor of >70
- X-ray beams brightness and coherent flux up to 500 times higher than currently
- Source beam size (rms), currently 280µm (h) x 10µm (v), after the upgrade
- brightness mode (324-bunches): 14.7µm (h) x 3.2µm (v)
- timing mode (48-bunches): 12.9µm (h) x 8.8µm (v)
(see Table 1.1 in APS Upgrade Project Final Design Review Report, Project Overview)
All areas of science will benefit from doubled X-ray flux and reduced X-ray beam size delivered to the samples after the APS-U. These and other benefits will be particularly large for experiments requiring sub-micron X-ray beams, high-energy, imaging (phase contrast), and experiments exploiting coherence.
Installation of the new APS storage ring will require a one-year shutdown of the APS, during which time X-ray beams will not be available to the scientific community. The installation and commissioning period is currently scheduled to begin in April 2023, with the upgraded APS coming online one year later. Initial operations will be at reduced ring current and availability as the machine is tuned up. APS expects to be at 100 mA within six months and at 200 mA roughly 12 months after the installation period ends.