A Molecular Movie
When a chemical reaction happens, atoms change their home molecule. The ultra short pulses of SwissFEL will for the first time allow for single atoms to be caught on the move.
The migration of atoms during a reaction goes on at an extremely fast pace. Bonds are broken up and new ones are forged within a span of some femto seconds. This is an incredibly short time! One femto second is just long enough for the fastest traveler in nature -light- to cover a distance equal to one tenth of the thickness of a human hair.
A Catalytic surface reactions triggered by THz pulses
Taking unblurred pictures of these processes requires an ultra fast "camera". In fact, one needs flashes of light, the duration of which should be just as short as some femto seconds with a wavelength as short as one tenth of a nanometer, in order to resolve the single atoms. This is exactly what SwissFEL provides!
For the first time, thus, chemists will be able to capture the motion of the atoms during a chemical reaction. By putting the single photos after one another, they will produce a kind of molecular
movierevealing the steps of a reaction as it unfolds.
Helping clean the air
One possible application of the ultra fast vision of the SwissFEL will be the detailed study of catalytic reactions.
Catalysts are substances that control the speed and path of a chemical reaction. They are widely used, for example to convert the poisonous exhaust gases of automobiles into less harmful ones. In spite of decades of industrial experience with catalysts, chemists still lack a thorough understanding of their inner workings. This means that catalysts are developed by blindly testing new materials. This leaves the chemists unsatisfied. They want to be able to proceed more rationally to produce new, more efficient, and specially tailored catalysts. SwissFEL will be a great help in this endeavor.