Credit: (Image by Daniel Haynes and Jörg Harms/Max Planck Institute for the Structure and Dynamics of Matter.)
Artistic depiction of XFEL measurement with neon gas. The inherent delay between the emission of photoelectrons and Auger electrons leads to a characteristic ellipse in the analyzed data. In principle, the position of individual data points around the ellipse can be read like the hands of a clock to reveal the precise timing of decay processes.