Publications by authors named "Wolfgang Hillert"
Article Synopsis
- X-ray free-electron lasers (XFELs) allow for novel experiments that traditional X-ray laser facilities cannot support, with more XFEL facilities being developed for greater pulse energies and brilliance.
- An important aspect of increasing pulse power is understanding the maximum pulse fluence that grazing-incidence FEL mirrors can handle.
- The study focuses on comparing the damage resistance of boron carbide (BC) coatings to polished silicon under soft X-ray FEL pulses, aiming to identify the potential benefits and limitations of using BC coatings in X-ray mirrors.
Due to their excellent photoemissive properties, especially low thermal emittance and high sensitivity in the green wavelength, multi-alkali antimonide photocathodes, in particular, cesium-potassium-antimonide, emerged as prominent photoemissive materials for the electron sources of high-repetition-rate FEL applications. To explore its feasibility of operating in a high-gradient RF gun, DESY collaborated with INFN LASA to develop multi-alkali photocathode materials. In this report, we describe the recipe of K-Cs-Sb photocathodes, which were grown on a Mo substrate by varying the foundational Sb layer thickness using sequential deposition techniques.
View Article and Find Full Text PDFNiobium's superconducting properties are affected by the presence and precipitation of impurities in the near-surface region. A systematic wide-temperature range x-ray diffraction study is presented addressing the effect of low temperatures (108 K-130 K) and annealing treatments (523 K in nitrogen atmosphere, 400 K in UHV) on the near-surface region of a hydrogen-loaded Nb(100) single-crystal. Under these conditions, the response of the natural surface oxides (NbO, NbO, and NbO) and the changes in the subsurface concentration of interstitial species in Nb are explored, thereby including the cryogenic temperature regime relevant for device operation.
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