Facility · Synchrotrons
Swiss Light Source (SLS 2.0)
Fourth-generation storage ring (2.7 GeV, seven-bend achromat with reverse bends)
- Status
- Operating
- Location
- Villigen, Switzerland
- Operator
- Paul Scherrer Institut (PSI)
- Next
- 2026 (autumn) most beamlines open to users (PSI plan, not confirmed)
Summary
The SLS upgrade began in September 2023: a new ring based on a seven-bend achromat with reverse bends, energy raised from 2.4 to 2.7 GeV, emittance improved up to 40 times, and brightness up to 1,000 times higher on some beamlines; two superconducting 5 T superbends, and NEG-coated vacuum chambers (SLS 2.0, accelerator). PSI's detector group, which develops hybrid pixel detectors, works at SLS.
Now as of 9 Nov 2026
Electrons have been back in the ring since February 2025 (PSI news of 25 February 2025), and the new SLS opened on 21 August 2025. PSI's plan: pilot users from the second half of 2025; a short second shutdown in early 2026 (additional undulators and superbends); regular operation of the first phase of beamlines from mid-2026; the second phase of beamlines from mid-2026; most beamlines by autumn 2026 (SLS 2.0, schedule, "subject to change"). Whether the plan has been met as of November 2026 has not been checked.
Key dates
- Sep 2023Upgrade ("dark time") beginsdone
- Feb 2025Electrons in the new ringdone
- 21 Aug 2025SLS 2.0 opensdone
- 2026 (early)Second short shutdownas planned
- 2026 (mid)Regular operation of the first phase of beamlinesplanned
- 2026 (autumn)Most beamlines open to usersplanned