SLAC sets record with hard X-ray pulses under 400 attoseconds

Researchers at SLAC's LCLS have generated and measured the shortest hard X-ray pulses ever produced at an XFEL, with durations of 100–400 attoseconds at photon energies around 9 keV. An indirect technique using amplified spontaneous emission and copper-foil fluorescence confirmed the pulse lengths for the first time.

• Pulse durations range from 100 to 400 attoseconds at ~9 keV
• Measurement used ASE and copper-foil fluorescence in a 150 nm spot
• 9 keV is an order of magnitude above earlier soft X-ray work below 5 keV
• Flashes capture samples before radiation damage sets in