XUV double-pulses with femtosecond to 650   ps separation from a multilayer-mirror-based split-and-delay unit at FLASH

Extreme ultraviolet (XUV) and X-ray free-electron lasers enable new scientific opportunities. Their ultra-intense coherent femtosecond pulses give unprecedented access to the structure of undepositable nanoscale objects and to transient states of highly excited matter. In order to probe the ultrafast complex light-induced dynamics on the relevant time scales, the multi-purpose end-station CAMP at the free-electron laser FLASH has been complemented by the novel multilayer-mirror-based split-and-delay unit DESC (DElay Stage for CAMP) for time-resolved experiments. XUV double-pulses with delays adjustable from zero femtoseconds up to 650   picoseconds are generated by reflecting under near-normal incidence, exceeding the time range accessible with existing XUV split-and-delay units. Procedures to establish temporal and spatial overlap of the two pulses in CAMP are presented, with emphasis on the optimization of the spatial overlap at long time-delays via time-dependent features, for example in ion spectra of atomic clusters.

Source: Journal of Synchrotron Radiation - August 3, 2018 Category: Physics Authors: Sauppe, M. Rompotis, D. Erk, B. Bari, S. Bischoff, T. Boll, R. Bomme, C. Bostedt, C. D ö rner, S. D ü sterer, S. Feigl, T. Fl ü ckiger, L. Gorkhover, T. Kolatzki, K. Langbehn, B. Monserud, N. M ü ller, E. M ü ller J.P. Passow, C. Ramm, D. Rolles, D. Tags: split-and-delay unit free-electron laser pump – probe multilayer mirror temporal and spatial overlap beamlines Source Type: research