Chemical Dynamics

Group Leader: Dr. Oriol Vendrell

Using an X-ray source, the positions of atoms in matter may be imaged. X-ray free-electron lasers, in particular, produce extremely intense radiation bursts that are so short that they are over before atoms have time to move. X-ray free-electron laser pulses can therefore be used to view chemical reactions as they occur, both in time and space. In this context, the Chemical Dynamics subgroup addresses fundamental questions related to the interaction of molecules and clusters with light, and to the application of modern photon sources to studying the dynamics of chemical processes with high spatial and temporal resolutions. This includes deciphering and also predicting the response of matter to the interaction with laser pulses, and proposing new operation modes and techniques that optimize the possibilities of such photon sources. On the other hand, the high intensity and energy of X-ray free-electron lasers are also a main source of damage to molecular systems, inducing changes to the electronic cloud that keeps the atoms together, and consequently to the molecular structure. Radiation damage also occurs in nature when molecules, proteins, etc. are hit by X-rays or other ionizing radiation. Describing and understanding the radiation damage process in a consistent fashion is an extremely challenging theoretical and numerical problem for which dedicated simulation tools are being developed in our group. Research in this area may lead to new ways to alleviate the impact of radiation damage.

Example of Coulomb explosion of a water cluster after ionization by a UV photon. The trajectory is 120 fs long.