Partner User Proposal Abstract
Ultrafast and Ultrasmall Laser X-ray Techniques (PUP-37)
We propose to develop the combination of ultrafast lasers and ultrasmall x-ray beams to study photo-induced dynamics in atoms and molecules. Such studies are not only foundational to proposed AMO experiments for next-generation x-ray light sources, e.g. the LCLS (Linac Coherent Light Source), but also markedly enhance the time-resolved capabilities at the Advanced Photon Source. One driving force for new ultrafast x-ray sources is the promise to visualize, on a subpicoseond timescale, photo-induced changes in local and bulk structure through time-resolved spectroscopies (NEXAFS, EXAFS) and time-resolved diffraction, respectively. Another major motivation is the promise of single-shot single biomolecule structure determination. Both of these applications benefit greatly from understanding and controlling the behavior of atoms and molecules in the presence of strong laser fields, the thrust of our research program. The strong field requirement necessitates focusing the laser to micron-size beam diameters and focusing the probe x-rays to within that diameter, thus the ultrafast and ultrasmall. The high brilliance of the Advanced Photon Source is essential for these time-resolved studies in the gas phase and the proposed laser upgrade (higher peak power, variable pulse length, higher repetition rate) will enable new classes of experiments as well as increase the productivity of current experiments. This PUP includes the laser upgrade, commissioning time, development of diagnostics for overlap of the ultrafast and ultrasmall, and experiments in AMO physics. At the conclusion of this work, the general user community will benefit from the proposed enhancements to the ultrafast laser facility, x-ray beamline and developments of diagnostic tools.
