2018, Siewert, F., Löchel, B., Buchheim, J., Eggenstein, F., Firsov, A., Gwalt, G., Kutz, O., Lemke, St., Nelles, B., Rudolph, I., Schäfers, F., Seliger, T., Senf, F., Sokolov, A., Waberski, Ch., Wolf, J., Zeschke, T., Zizak, I., Follath, R., Arnold, T., Frost, F., Pietag, F., Erko, A.

Blazed gratings are of dedicated interest for the monochromatization of synchrotron radiation when a high photon flux is required, such as, for example, in resonant inelastic X-ray scattering experiments or when the use of laminar gratings is excluded due to too high flux densities and expected damage, for example at free-electron laser beamlines. Their availability became a bottleneck since the decommissioning of the grating manufacture facility at Carl Zeiss in Oberkochen. To resolve this situation a new technological laboratory was established at the Helmholtz Zentrum Berlin, including instrumentation from Carl Zeiss. Besides the upgraded ZEISS equipment, an advanced grating production line has been developed, including a new ultra-precise ruling machine, ion etching technology as well as laser interference lithography. While the old ZEISS ruling machine GTM-6 allows ruling for a grating length up to 170 mm, the new GTM-24 will have the capacity for 600 mm (24 inch) gratings with groove densities between 50 lines mm−1 and 1200 lines mm−1. A new ion etching machine with a scanning radiofrequency excited ion beam (HF) source allows gratings to be etched into substrates of up to 500 mm length. For a final at-wavelength characterization, a new reflectometer at a new Optics beamline at the BESSY-II storage ring is under operation. This paper reports on the status of the grating fabrication, the measured quality of fabricated items by ex situ and in situ metrology, and future development goals.

2018-8-3, Sauppe, Mario, Rompotis, Dimitrios, Erk, Benjamin, Bari, Sadia, Bischoff, Tobias, Boll, Rebecca, Bomme, Cédric, Bostedt, Christoph, Dörner, Simon, Düsterer, Stefan, Feigl, Torsten, Flückiger, Leonie, Gorkhover, Tais, Kolatzki, Katharina, Langbehn, Bruno, Monserud, Nils, Müller, Erland, Müller, Jan P., Passow, Christopher, Ramm, Daniel, Rolles, Daniel, Schubert, Kaja, Schwob, Lucas, Senfftleben, Björn, Treusch, Rolf, Ulmer, Anatoli, Weigelt, Holger, Zimbalski, Jannis, Zimmermann, Julian, Möller, Thomas, Rupp, Daniela

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.

2018-8-2, Erk, Benjamin, Müller, Jan P., Bomme, Cédric, Boll, Rebecca, Brenner, Günter, Chapman, Henry N., Correa, Jonathan, Düsterer, Stefan, Dziarzhytski, Siarhei, Eisebitt, Stefan, Graafsma, Heinz, Grunewald, Sören, Gumprecht, Lars, Hartmann, Robert, Hauser, Günter, Keitel, Barbara, von Korff Schmising, Clemens, Kuhlmann, Marion, Manschwetus, Bastian, Mercadier, Laurent, Müller, Erland, Passow, Christopher, Plönjes, Elke, Ramm, Daniel, Rompotis, Dimitrios, Rudenko, Artem, Rupp, Daniela, Sauppe, Mario, Siewert, Frank, Schlosser, Dieter, Strüder, Lothar, Swiderski, Angad, Techert, Simone, Tiedtke, Kai, Tilp, Thomas, Treusch, Rolf, Schlichting, Ilme, Ullrich, Joachim, Moshammer, Robert, Möller, Thomas, Rolles, Daniel

The non-monochromatic beamline BL1 at the FLASH free-electron laser facility at DESY was upgraded with new transport and focusing optics, and a new permanent end-station, CAMP, was installed. This multi-purpose instrument is optimized for electron- and ion-spectroscopy, imaging and pump–probe experiments at free-electron lasers. It can be equipped with various electron- and ion-spectrometers, along with large-area single-photon-counting pnCCD X-ray detectors, thus enabling a wide range of experiments from atomic, molecular, and cluster physics to material and energy science, chemistry and biology. Here, an overview of the layout, the beam transport and focusing capabilities, and the experimental possibilities of this new end-station are presented, as well as results from its commissioning.