Workshop on Time Domain Science Using X-ray Techniques
August 29 September 1, 2004, The Abbey, Fontana, Lake Geneva Area, Wisconsin
The field of time domain scientific experiments using hard x-rays from synchrotron radiation sources is now gaining momentum. The time range covered by ongoing and future experiments is from sub-picoseconds to thousands of seconds which is 16 to17 decades of spread. The scientific disciplines which will benefit from these studies include atomic and molecular physics, biology, chemical science, condensed matter physics, engineering science, environmental science, material science, and nuclear science. It is no exaggeration to point out that the field is at its infancy in the light of future potential. This is mainly because the traditional material science, chemistry and biology communities are getting the early glimpse of the potential impact of time resolved x-ray studies. Secondly, the ps and fs optical lasers, some with high power, used as pumps in many x-ray pump-probe experiments have become available only recently. Finally, the success of the future scientific research at the storage ring sources will lay a foundation for planning scientific experiments at the future x-ray FELs. Hence it is very timely to hold a workshop focused on the future scientific potential in the time resolved x-ray field.
The time resolved experiments at a storage ring can be broadly classified as follows:
- Pump-probe experiments synchronized with the storage ring filling pattern.
- Pump-probe experiments without a storage ring synchronization
- Frequency domain experiments
- Experiments which measure space and time auto correlation
Most of the x-ray scattering experiments usually measure the equilibrium dynamics of the condensed matter in the energy and/or momentum space. These experiments fall in class (d) above, such as diffraction (XRD), small- and wide-angle x-ray scattering (SAXS and WAXS), x-ray intensity correlation spectroscopy (XICS), magnetic scattering, x-ray magnetic circular and linear dichroism (XMCD and XMLD), and inelastic x-ray scattering (IXS), and nuclear resonant (elastic and inelastic) scattering (NRS), and they provide the Fourier transforms of the density or charge or spin correlations in equilibrium. Per se the emphasis of the proposed workshop will not be on this kind of research which is already well rooted in the scientific programs at all the synchrotron radiation facilities. On the other hand the same studies and techniques provide new information if they are performed to understand the time dependent processes. In other words when these techniques are used as a probe in pump-probe experiments they provide insight into the non-equilibrium response of the system to the excitation as a function of time.
The purpose of this workshop is to explore emerging scientific opportunities using x-ray time resolved techniques, and to seek input from scientists from laser, x-ray and accelerator fields who will participate in the future of this field.
The four major topics for the workshop are:
- Atomic, molecular and nuclear sciences
- Chemical and biological sciences
- Condensed matter physics and material sciences
- Accelerator physics to address delivery of picosecond x-ray pulses at the APS.