SOLEIL

SOLEIL, in the Paris-Saclay research cluster some twenty kilometres south of Paris, is the French national synchrotron — a third-generation light source famous for its reliability and for being the first in the world to operate in continuous top-up mode.

Opened to users in 2008, SOLEIL covers an exceptionally broad spectral range, from the far infrared to hard X-rays, through 29 beamlines offering complementary experimental techniques. A staff of around 400 keeps it among the most stable and reliable synchrotrons in operation, and it now also offers users a Titan Krios cryo-electron microscope alongside its photon beamlines. More than five thousand researchers from around the world come to SOLEIL every year.

At a glanceFacility profile

Location

Saint-Aubin, Paris-Saclay, France

Operator

Synchrotron SOLEIL (CNRS and CEA)

Type

Third-generation synchrotron, infrared to hard X-rays

Energy

2.75 GeV

Beam current

Up to 500 mA, top-up operation

Beamlines

29 in operation

First light

Open to users 2008

Website

synchrotron-soleil.fr

The scienceWhat researchers do here

The breadth of SOLEIL’s spectrum lets a single facility serve work that ranges from far-infrared and terahertz spectroscopy to high-resolution X-ray diffraction and imaging. Researchers study catalysts and battery materials under working conditions, the electronic and magnetic structure of quantum materials, protein structures and biological macromolecules, and the chemistry of complex molecules in the gas phase. Beamlines such as PUMA are also used in archaeology and cultural-heritage science to examine fragile and ancient objects without damaging them.

A pioneer of top-up operation: by topping up its electron beam continuously, SOLEIL keeps its X-rays rock-steady for the most demanding experiments.

The next generationThe SOLEIL II upgrade

SOLEIL’s teams are preparing SOLEIL II, a comprehensive upgrade built around a new diffraction-limited storage ring together with a major refurbishment of the beamlines and their environment. The current machine is planned to operate until autumn 2028; SOLEIL II is scheduled to start up in 2030, with a gradual ramp-up to full capability by 2035, sharply increasing brightness and coherence for nanoscale imaging and spectroscopy.