Physicists First to Observe Electron Ejected from Atom Published Dec. 13, 2011 By Maria Callier, AFRL/AFOSR Office of Scientific Research ARLINGTON, Virginia -- Air Force Research Lab-supported physicists at the University of California, Berkeley, in collaboration with researchers from the Max Planck Institute of Quantum Optics and the U.S. Department of Energy's Lawrence Berkeley National Laboratory, became the first researchers to observe the motion of an atom's valence in real time by investigating the ejection of an electron from an atom by an intense laser pulse. In the experiments, an electron in a krypton atom is removed by a laser pulse that lasts less than four femtoseconds (one femtosecond is one millionth of one billionth of a second). This process leaves behind an atom with a pulsating positively charged hole in the valence shell, which originates from electronic wave functions of the atom. The scientists used an extreme ultraviolet light pulse, the duration of which was 150 attoseconds (one attosecond is one billionth of one billionth of a second), to capture and photograph the movement of valence electrons for the first time. This research is expected to enable the scientists to better control processes and materials that will improve high-speed electronics and carbon-free energy sources that will benefit both the Air Force and consumers.