Facility · X-ray lasers
SwissFEL
X-ray free-electron laser on a normal-conducting linac up to 5.8 GeV, with the Aramis (hard X-ray) and Athos (soft X-ray) lines
- Status
- Operating
- Location
- Villigen, Switzerland
- Operator
- Paul Scherrer Institut (PSI)
- Next
- 2029–2032 SwissFELplus upgrade: seeding in the hard and soft X-ray ranges, preparation of a new line (plan)
Summary
PSI's compact X-ray free-electron laser, in operation since 2016: electron energy 2.1–5.8 GeV, 100 pulses per second on each line. Aramis covers 1–7 Å and Athos 6.5–50 Å, together 0.25–12 keV; there are five experimental stations, with a sixth under construction (SwissFEL, accelerator). With a free-electron laser and a detector group on the same site, SwissFEL is a useful comparison to the megahertz European XFEL: a different pulse structure sets different requirements for the detectors.
Now as of 9 Nov 2026
The user programme runs as normal. The next step is SwissFELplus: according to T. Schietinger's talk at IPAC'26 (21 May 2026), the project is planned for 2029–2032 and should bring full coherence in hard and soft X-rays through self-seeding and seeding with an external laser, and prepare a new line (JACoW IPAC'26, THP2084). Earlier, a third line, Porthos (very hard X-rays), appeared in the PSI roadmap for 2029/30 (PSI slides, 2021); how Porthos relates to the "new line" of SwissFELplus is not yet clear. The long shutdown of the HIPA proton complex (SINQ, SμS, CHRISP; from late 2027 to September 2029) does not affect SwissFEL.
Key dates
- 2016Start of operationdone
- 2029–2032SwissFELplus: seeding, preparation of a new lineplanned
Timeline
- 21 May 2026SwissFELplus plan presented at IPAC'26 — JACoW