Journal Article

Free-Electron Laser in Hamburg (FLASH), first launched in 2005, was the first free-electron laser that provided ultrashort radiation pulses in extreme ultraviolet and soft X-ray spectral range. In 2017, it was decided to improve the existing FLASH facility within the FLASH2020+ project, which led to upgrading the existing linac with variable gap tunable undulators in the FLASH1 line and refurbishing two cryomodules to achieve a beam energy increase to 1.35 GeV. [...]

The monolithic fabrication of passive, nonlinear, and active functionalities on asingle chip is highly desired in the wake of the development and commercialization of integratedphotonic platforms. However, the co-integration of diverse functionalities has been challengingas each platform is optimized for specific applications, typically requiring different structuresand fabrication flows [...]

Graphene and its derivatives, such as graphene oxide (GO) and reduced graphene oxide (rGO), havepropelled advancements in biosensor research owing to their unique physicochemical and electroniccharacteristics. To ensure their safe and effective utilization in biological environments, it is crucial tounderstand how these graphene-based nanomaterials (GNMs) interact with a biological milieu. [...]

We demonstrate high energy Q-switched pulse generation with the help of a large mode area gain waveguide in a silicon photonics device. Output pulse energy >150 nJ and laser slope efficiency of 40% is shown..

MADMAX, a future experiment to search for axion dark matter,is based on a novel detection concept called the dielectrichaloscope. It consists of a booster composed of several dielectricdisks positioned with μm precision. [...]

We propose a consistent framework with the U(1) Peccei–Quinn (PQ) symmetry for obtaining the initial condition for axion kinetic misalignment from inflation. We introduce a PQ complex scalar field and an extra Higgs doublet, which are conformally coupled to gravity, and three right-handed neutrinos for the seesaw mechanism. [...]

Making use of conformal symmetry of large-n$_{f}$ QCD in d = 4 – 2ϵ dimensions at the Wilson-Fischer fixed point, we calculate the two-loop coefficient functions in the operator product expansion of two electromagnetic currents in general kinematics with two different photon virtualities. This result is necessary for the description of the double deeply virtual Compton scattering to the next-to-next-to-leading order accuracy, but is also interesting for a range of other two-photon processes. [...]

Ferrous medium-entropy alloys (FeMEAs), leveraging deformation-induced martensitic transformation (DIMT), demonstrate excellent strain-hardening ability attributed to the transformation-induced plasticity (TRIP) effect. To improve the low yield strength of FeMEAs, the initial microstructure was controlled by utilizing partial recrystallization. [...]

The production of methanol (CH3OH) from CO2 is an attractive solution for closing the carbon cycle and thus addressing both environmental concerns and raw material changes in the chemical industry. CuZn-based catalysts are the most intensively investigated materials in this regard but suffer from CH3OH decomposition to CO with increasing CO2 conversion [...]

The enhancement of mechanical performance in Inconel 718 fabricated via Laser Powder Bed Fusion by optimizingprocess parameters and various post-processing heat treatments, such as double aging and hightemperatureisostatic pressing, are explored. Phase and texture evolution were characterized by high-energydiffraction electron backscatter diffraction analysis, showing a weak Goss-type texture in the as-built condition.Carrying out a homogenization annealing above δ solvus, e.g. [...]