Diffraction-limited storage ring

Diffraction-limited storage rings (DLSR), or ultra-low emittance storage rings, are synchrotron light sources where the emittance of the electron-beam in the storage ring is smaller or comparable to the emittance of the x-ray photon beam they produce at the end of their insertion devices. These facilities operate in the soft to hard x-ray range (100eV—100keV) with extremely high brilliance (in the order of 10²¹—10²² photons/s/mm²/mrad²/0.1%BW)

Together with X-ray free-electron lasers, they constitute the fourth generation of light sources,^[1] characterized by a relatively high coherent flux (in the order of 10¹⁴—10¹⁵photons/s/0.1%BW for DLSR) and enable extended physical and chemical characterizations at the nano-scale.

Existing diffraction-limited storage rings

• MAX IV Laboratory, in Lund, Sweden.
• Sirius, in Campinas, Brazil
• European Synchrotron Radiation Facility, Extremely Brilliant Source (ESRF-EBS), in Grenoble, France

DLSR upgrade or facilities under construction

• Advanced Photon Source Upgrade (APS-U), in Argonne, Illinois, USA
• Swiss Light Source 2, Upgrade (SLS 2.0^[2]), in Villigen, Switzerland

Planned or projected DLSR upgrades or new facilities

Upgrades

• PETRA IV, Upgrade (PETRA IV), at DESY, Hamburg, Germany
• Advanced Light Source, Upgrade (ALS-U), in Berkeley, California, USA
• Diamond II (Diamond II), in Didcot, Oxfordshire, UK
• ELETTRA 2.0 (Elettra 2.0), in Trieste, Italy
• ALBA II, in Barcelona, Spain^[3]
• SOLEIL II, in Saint-Aubin, France^[4]

New facilities

• High Energy Photon Source (HEPS), in Beijing, China^[5][6]

See also

• X-Ray Free Electron Lasers