Phys. Rev. Lett. 103, 152301 (2009)

Scientists want to image atomic processes occurring in real time, which requires extremely short pulses of light. Current state-of-the-art lasers can take attosecond (10−18 second) snapshots, but Andreas Ipp, Christoph Keitel and Jörg Evers at the Max Plank Institute for Nuclear Physics in Heidelberg, Germany, think that they can do a million times better using heavy-ion collisions.

When nuclei such as those of lead or gold collide, the quarks inside protons and neutrons briefly become free to move on their own. Over the course of a few yoctoseconds (10−24 second) they expand, releasing a super-short pulse of light. Only a few yoctosecond-long photons would be released by even the highest-energy collisions, but on the basis of their calculations, the authors believe that under the right conditions, the pulses could be used for ultrafast imaging.