Research

Method refinement for MAX IV

2015-03-31

To take full advantage of future experiments at the MAX IV facility in Lund, advanced method development is pursued at Uppsala University, among others. An investigation, which gives new insights into resonant inelastic X-ray scattering (RIXS), is published online today in Physical Review Letters.

RIXS is a method which has a wide scope, ranging from dynamics in batteries, solar cells, and chemical reactions in general to complex magnetic structures and superconductors. Researchers at Uppsala University have the responsibility for building the VERITAS beamline at MAX IV. At this beamline the RIXS method will be refined so that it can be used in completely new ways.

To investigate details in the X-ray scattering dynamics, Uppsala physicists have used the nitrogen molecule as a simple model system. Together with researchers from MAX IV, HZB Berlin and PSI Villigen in Switzerland they have mapped in detail what happens in the immediate vicinity of the threshold where an inner electron can be removed from the molecule.

During a very short time, before the hole it leaves behind is filled, the electron is found in an uncertain state. According to the Heisenberg uncertainty relation it cannot know if it is on its way out or not; it is balancing on the edge. After a few exciting femtoseconds the hole is filled and the drama is over. Now, the electron either stays in a well-defined state, or leaves the molecule. The probabilities for the two outcomes can be calculated using quantum mechanics.

‘It is fun to see the familiar nitrogen molecule in states where it hasn’t been seen before, but most important are the insights about the ultrafast dynamics. They will be important when interpreting results from future measurements at MAX IV. There we will focus our attention on electron dynamics in technically relevant systems and processes’, says professor Jan-Erik Rubensson.

Read the article in Physical Review Letters.