# European XFEL attosecond X-ray pulse breakthroughs

> Live situation record from CLSTR: https://clstr.news/situations/european-xfel-attosecond-x-ray-pulse-breakthroughs
> Updated: 2026-10-21T16:44:31.000Z. Sources: 4. Developments: 2.

Researchers using the European XFEL have achieved a world record in the intensity and fluence of hard X-ray attosecond pulses. By employing an advanced Kirkpatrick–Baez optical system with high-precision mirrors, the team focused X-ray flashes into an area approximately 180 by 330 nanometres. These pulses, estimated to last between 100 and 400 attoseconds, allow for peak intensities exceeding 10^20 watts per square centimeter.

Collaborative efforts involving the European XFEL and SLAC’s Linac Coherent Light Source (LCLS) utilized indirect measurement techniques, such as amplified spontaneous emission, to precisely calculate pulse duration. This milestone enables the real-time observation of electron motion within atoms and molecules, capturing structural data before radiation damage occurs. Such capabilities may eventually allow scientists to study nonlinear interactions and control electron movement during chemical reactions.

## Timeline

### 2026-10-21: Researchers achieve record-breaking attosecond X-ray pulse intensity

Researchers have achieved a world record in intensity and flux density for attosecond hard X-ray pulses, enabling real-time observation of electron movement in atoms and molecules.

2 sources. https://clstr.news/cluster/researchers-achieve-record-breaking-attosecond-x-ray-pulse-intensity

### 2026-10-16: European XFEL researchers achieve record X-ray pulse intensity

Scientists at the European XFEL have set a world record by concentrating 300-attosecond X-ray pulses into a microscopic area, enabling unprecedented study of electron behavior in atoms.

2 sources. https://clstr.news/cluster/european-xfel-researchers-achieve-record-x-ray-pulse-intensity

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Cite as: European XFEL attosecond X-ray pulse breakthroughs. CLSTR, https://clstr.news/situations/european-xfel-attosecond-x-ray-pulse-breakthroughs