Development of a source of femtosecond X-ray pulses based on the electron storage ring

The dynamic properties of materials are governed by atomic motion which occur on the fundamental time scale of a vibrational period /spl sim/100 fs. This is the time scale of interest for ultrafast chemical reactions, non-equilibrium phase transitions, vibrational energy transfer, surface desorption and reconstruction, and coherent phonon dynamics. To date, our understanding of these processes has been limited by lack of appropriate tools for probing atomic structure on an ultrafast time scale. The time resolution of high-brightness 3rd generation synchrotron light sources is more than two orders of magnitude too slow for these studies. However, the desired X-ray pulses may be achieved by selecting radiation which originates from a thin /spl sim/100 fs temporal slice of an electron bunch.