ASTRID2 is a third-generation low-emittance light source at Aarhus University, Denmark. Commissioned in 2013, the facility provides state-of-the-art high-brilliance light from the low-emittance electron beam, operating in top-up mode to give an infinite beam lifetime.

The ASTRID storage ring was a second generation synchrotron radiation source, which started operation in the early nineties and is now used solely as a booster for the new ASTRID2 ring. Many of the beam lines from ASTRID have been upgraded and transferred to ASTRID2 and two completely new beam lines have been constructed and are now in operation. The newest beam line, AU-SGM4, has been commissioned and operational since early 2023.

Photons are available from the infrared to soft x-ray regime, and beam lines and end-stations cover use in areas from biology to physics. Techniques include, for example, linear/circular dichroism for molecular biology and angular resolved photo emission spectroscopy.

The ISA laboratory, which amongst other things operates the ASTRID2 facility, is part of Aarhus University. Around 150 scientists use the light source annually with about half coming from abroad. A user selection panel assigns beam time to selected proposals once per year, based on scientific merit.

To view the current beam status in ASTRID2 please visit

Storage Ring Specifications ASTRID2
Energy 0.58 [GeV]
Max Current 200 [mA]
Circumference 45.7 [m]
Lattice Architecture 6-fold double bend achromat with combined function magnets
Number Of Straight Sections In Use 3
Average Beam Lifetime 2 [h]
Top-up Yes
Current At Top-up 180 [mA]
Beam Revolution Frequency 6.559 [MHz]
Emittance 12 [nm*rad]
Filling Pattern Uniform, working on single bunch operation.
Harmonic Number 16
Beam Size In Insertion Devices (hor x ver) X = 220 [um], Y = 55 [um]
Beam Size In Bending Magnets (hor x ver) X = 100 [um], Y = 140 [um]
Aarhus University
ISA, Department of Physics & Astronomy, Aarhus University, Ny Munkegade 120, Building 1520 Aarhus
call for proposals

There is currently no open ISA call for proposals, the next will be in the autumn of 2024. However, eligible users may apply through EU programmes detailed on the ISA website.