The team used the instrument to map the fastest atomic movements of a molecule called ferricyanide. SLAC scientists Dimosthenis Sokaras, Marco Reinhard and Roberto Alonso Mori at LCLS’s XCS instrument. Combining information from both regions enabled the team to obtain a detailed picture of the ferricyanide molecule as it evolved into a key transitional state. Instead of studying only one spectroscopic region, known as the Kβ main emission line, the team captured and analyzed a second emission region, called valence-to-core, which has been significantly more challenging to measure on ultrafast timescales. What was different this time is how the researchers extracted information from the X-ray data. The ultraviolet light kicked the molecule into an excited state while the X-rays probed the sample’s atoms, revealing features of ferricyanide's atomic and electronic structure and motion. The research team from SLAC, Stanford and other institutions started with what is now a fairly standard technique: They zapped a mixture of ferricyanide and water with an ultraviolet laser and bright X-rays generated by the Linac Coherent Light Source (LCLS) X-ray free-electron laser. They think their approach could help map more complex chemical reactions like oxygen transportation in blood cells or hydrogen production using artificial photosynthesis.

Researchers at SLAC National Accelerator Laboratory captured one of the fastest movements of a molecule called ferricyanide for the first time by combining two ultrafast X-ray spectroscopy techniques.

Phototime in x ray