X-ray pulse compressors in Laue diffraction geometry.

We theoretically investigate the impact of nonlinear dispersion of crystals and multilayers used in Laue-type pulse compressors (LPCs) on chirped x-ray pulse compression, as well as the optimization method for the configuration of LPCs. We also study the application of LPCs to compress chirped x-ray free-electron laser pulses based on the parameters of LCLS-II-HE. The results show that the optimal thickness is half of the Pendellosung period, yielding the best compressor performance with minimal impact from the nonlinear dispersion.

FURION: modeling of FEL pulses propagation in dispersive soft X-ray beamline systems.

Modern X-ray free-electron lasers (XFELs) can generate pulses with durations ranging from femtoseconds to attoseconds. The numerical evaluation of ultra-short XFEL pulses through beamline systems is a critical process of beamline system design. However, the bandwidth of such ultra-short XFEL pulses is often non-negligible, and the propagation cannot be simply approximated using the central wavelength, especially in dispersive beamline systems.

High-efficiency focusing and imaging by dielectric kinoform zone plate lenses with soft X-rays.

With fast advances in enhancing the focusing/imaging resolution of Fresnel zone plate lenses toward sub-10 nm, low diffraction efficiency in connection with their rectangular zone shape still remains a big issue in both soft and hard X-ray microscopy. In hard X-ray optics, encouraging progress has recently been reported in our earlier attempts of high focusing efficiency by 3D kinoform shaped metallic zone plates, formed by greyscale electron beam lithography. This paper addresses our efforts towards high focusing/imaging efficiency by developing a novel dielectric kinoform zone plate lens for soft X-rays.

Health expenditures, environmental quality, and economic development: State-of-the-art review and findings in the context of COP26.

There are numerous factors that affect human health. Among others, environmental degradation, bad governance, and extensive economic growth are regarded as more destructive for health-related issues. To explore the nexus of the said factors and extend the scholarly literature, the current study aims to analyze the influence of greenhouse gas (GHG) emissions, governance indicators, and gross domestic product (GDP) on human health expenditures-captured by domestic health expenditures and capital health expenditures.

Trapezoid-kinoform zone plate lens - a solution for efficient focusing in hard X-ray optics.

X-ray microscopes are powerful tools in the nano-inspection of materials owing to their ultra-high resolution at the molecular level. However, the focusing efficiency of binary zone plate lenses as key components in such probes is merely 5% in practice, hindering their application in advanced scientific research. Although kinoform zone plate lenses are in principle supposed to possess high efficiency beyond binary ones, little progress has been reported so far due to the shortage of both a theoretical calculation approach and greyscale lithography for generating fine three-dimensional (3D) kinoform zones of the lenses.

Virtual depth-scan multi-slice ptychography for improved three-dimensional imaging.

Multi-slice ptychography (MSP) is a fast three-dimensional ptychography technology developed on the basis of conventional ptychography. With this method, three-dimensional imaging can be achieved without rotating the sample. The prototype multi-slice algorithm can only reconstruct three-dimensional samples with a limited number of slices, which greatly limits the depth range and resolution of sample imaging.

In Situ Formation of Hierarchical Bismuth Nanodots/Graphene Nanoarchitectures for Ultrahigh-Rate and Durable Potassium-Ion Storage.

Metallic bismuth (Bi) has been widely explored as remarkable anode material in alkali-ion batteries due to its high gravimetric/volumetric capacity. However, the huge volume expansion up to ≈406% from Bi to full potassiation phase K Bi, inducing the slow kinetics and poor cycling stability, hinders its implementation in potassium-ion batteries (PIBs). Here, facile strategy is developed to synthesize hierarchical bismuth nanodots/graphene (BiND/G) composites with ultrahigh-rate and durable potassium ion storage derived from an in situ spontaneous reduction of sodium bismuthate/graphene composites.

Three-dimensional focal stack imaging in scanning transmission X-ray microscopy with an improved reconstruction algorithm.

Focal stack (FS) is an effective technique for fast 3D imaging in high-resolution scanning transmission X-ray microscopy. Its crucial issue is to assign each object within the sample to the correct position along the optical axis according to a proper focus measure. There is probably information loss with previous algorithms for FS reconstruction because the old algorithms can only detect one focused object along each optical-axial pixel line (OAPL).

Spatially correlated coherent diffractive imaging method.

Coherent diffractive imaging (CDI) is a lensless, high-resolution imaging method that is currently under rapid development by using X-rays, visible light, or electrons. However, its inherent ambiguities and the need of a priori knowledge about objects are limiting applications based on this method. By combining a conventional CDI method with the basic idea of ptychography, the method of spatially correlated CDI, a method fit for multiple sample imaging in single-shot mode, is proposed to enhance the robustness of CDI.