Disruptive photon technologies for chemical dynamics

Abstract

A perspective of new and emerging technologies for chemical dynamics is given, with an emphasis on the use of X-ray sources that generate sub-picosecond pulses. The two classes of experimental techniques used for time-resolved measurements of chemical processes and their effects are spectroscopy and imaging, where the latter includes microscopy, diffractive imaging, and crystallography. X-ray freeelectron lasers have brought new impetus to the field, allowing not only temporal and spatial resolution at atomic time and length scales, but also bringing a new way to overcome limitations due to perturbation of the sample by the X-ray probe by out-running radiation damage. Associated instrumentation and methods are being developed to take advantage of the new opportunities of these sources. Once these methods of observational science have been mastered it should be possible to use the new tools to directly control those chemical processes.

Toward spatial and spectral control of waveguided high-harmonic generation

“…There are a number of fundamentally different approaches to generate radiation in the XUV band. For a comparison, Fig.1.1 summarizes the peak spectral brightness (brilliance) [6] as a function of photon energy (wavelength), for the laser-produced plasma sources (LPP [7]), synchrotrons (ALS [8] and ESRF [9]), free-electron lasers (FLASH [10], XFEL [11] and LCLS [12]) and via nonlinear optical generation, i.e., high-order harmonic generation. From Fig.1.1, it can be seen that the free electron lasers deliver the highest brightness values compared to other sources with wavelength ranging from 124 to 0.124 nm.…”