Imaging dynamics of molecules

Imaging dynamics of small molecules

Intensity distribution of emitted proton (H+) and oxygen ion (O)+ viewed by our detector when the water molecule is resonantly excited by X-rays.

Atoms and molecules in electronically excited states decay via various processes which lead to bond breaking and ion formation, producing neutral and charged constituents that react with their neighbors. These processes occur everywhere, from car engines to industrial chemical plants. Ionization processes occur naturally in the Earth's upper atmosphere and at the Earth's surface and are largely responsible for radiation damage in biological molecules. Generally high-energy photoionization or collisional ionization leads to a greater the number of possible reaction pathways for higher energy transfer resulting in greater “damage” to the system.

On a fundamental level we are able to image the molecule by careful measurement of the ion trajectories. This provides a tool for connecting molecular geometry in fragmentation to kinematics and to the time scale of competing processes. This is a major field of research and momentum spectroscopy can help to answer fundamental questions which play an important role in many branches of physics, chemistry and biology.

Collaborators at Lund University

• Noelle Walsh
• Per Johnsson