Capturing nature's fastest processes at atomic scale with unprecedented clarity
Imagine watching molecules dance in real time or witnessing electrons rearrange during chemical reactions. For decades, these atomic-scale events remained invisible, unfolding too quickly and too small for any microscope to capture. Today, a revolutionary upgrade at the SLAC National Accelerator Laboratory has transformed this dream into reality. The Linac Coherent Light Source (LCLS-II) now fires one million X-ray pulses per second—10,000 times brighter than its predecessor—allowing scientists to create "molecular movies" of processes that govern everything from renewable energy to disease treatment 3 . This breakthrough isn't just a technical marvel; it's rewriting textbooks across physics, chemistry, and biology.
At its core, LCLS-II is an X-ray free-electron laser (XFEL). It accelerates electrons to near-light speeds, forces them through undulating magnets, and harvests the X-rays they emit. The 2025 upgrade introduced a superconducting accelerator cooled to -456°F, enabling continuous X-ray bursts at unprecedented rates 3 .
"We're no longer limited by a narrow window. This upgrade made previously impossible research possible"
— Matthias Kling, LCLS Director of Science 3
Electrons are accelerated to near-light speed in a superconducting linear accelerator.
Magnets force electrons into a slalom path, emitting X-rays.
X-ray pulses are generated at femtosecond durations.
| Feature | Before | After |
|---|---|---|
| Pulse Rate | 120 pulses/sec | 1,000,000 pulses/sec |
| Brightness | 1x | 10,000x |
| Pulse Duration | 100 femtoseconds | 1 femtosecond |
One flagship instrument, the Dynamic REAction Microscope (DREAM), captures chemical reactions frame by frame.
| Stage | Pre-Upgrade (2020) | Post-Upgrade (2025) |
|---|---|---|
| Data for 1 frame | 1 week | 5 minutes |
| Full reaction movie | ~3.5 years | 8 hours |
| Resolution | 5 Ã… | 1.2 Ã… |
While DREAM studies reactions, the quantum RIXS (qRIXS) instrument explores materials with bizarre quantum properties. Its 12-foot, rotating spectrometer analyzes how X-rays scatter from electrons in solids, exposing hidden states of matter 3 .
| Parameter | Pre-Upgrade | Post-Upgrade | Improvement |
|---|---|---|---|
| Data collection speed | 1 photon/day | 100 photons/sec | 8,640,000x |
| Measurement duration | Days | Minutes | 99% faster |
| Energy resolution | 500 meV | 50 meV | 10x sharper |
Essential instruments and reagents powering these experiments:
| Tool/Reagent | Function | Example Use Case |
|---|---|---|
| Cryo-cooled crystals | Samples frozen to preserve atomic structure during X-ray exposure | Imaging protein dynamics in vaccines |
| Resonant RIXS spectrometer | Detects faint light emitted from excited electrons | Mapping quantum behavior in superconductors |
| Femtosecond optical lasers | Triggers reactions synchronized with X-ray pulses | Studying photosynthesis initiation |
| Lipid nanoparticle carriers | Delivers biological samples without damage | Analyzing membrane proteins in real time |
| AI reconstruction algorithms | Converts fragment data into 3D molecular movies | Visualizing drug binding to viruses |
LCLS-II's atomic snapshots are accelerating innovations:
Watching antibodies neutralize viruses informs designer drugs for influenza and HIV.
Filming catalyst surfaces during reactions reveals ways to boost clean hydrogen production.
The facility also trains AI models on its massive datasets, enabling virtual experiments that predict new superconductors or enzyme designs 3 .
As we celebrate the UN's International Year of Quantum Science and Technology in 2025, tools like LCLS-II epitomize a new era of discovery 1 . Planned upgrades aim for attosecond pulses (a billionth of a billionth of a second) to track electron movements. Meanwhile, spin-off technologies are already emerging:
"This is more than an upgrade; it's a new lens on reality"
— James Cryan, SLAC 3