A zone-plate-based two-color spectrometer for indirect X-ray absorption spectroscopy

Abstract

X-ray absorption spectroscopy (XAS) is a powerful element-specific technique that allows the study of structural and chemical properties of matter. Often an indirect method is used to access the X-ray absorption (XA). This work demonstrates a new XAS implementation that is based on off-axis transmission Fresnel zone plates to obtain the XA spectrum of La0.6Sr0.4MnO3 by analysis of three emission lines simultaneously at the detector, namely the O 2p–1s, Mn 3s–2p and Mn 3d–2p transitions. This scheme allows the simultaneous measurement of an integrated total fluorescence yield and the partial fluorescence yields (PFY) of the Mn 3s–2p and Mn 3d–2p transitions when scanning the Mn L-edge. In addition to this, the reduction in O fluorescence provides another measure for absorption often referred to as the inverse partial fluorescence yield (IPFY). Among these different methods to measure XA, the Mn 3s PFY and IPFY deviate the least from the true XA spectra due to the negligible influence of selection rules on the decay channel. Other advantages of this new scheme are the potential to strongly increase the efficiency and throughput compared with similar measurements using conventional gratings and to increase the signal-to-noise of the XA spectra as compared with a photodiode. The ability to record undistorted bulk XA spectra at high flux is crucial for future in situ spectroscopy experiments on complex materials.

Prediction on X-ray output of free electron laser based on artificial neural networks

“…c Single-shot X-ray wavefronts were measured using a Talbot wavefront sensor [21][22][23] . The single-shot X-ray spectra were measured using an off-axis X-ray zone plate spectrometer 24,25 . d From the recorded single-shot electron and X-ray data, a heat map displaying the Pearson correlation coefficients is produced, highlighting the relationship between the electron parameter inputs with the X-ray wavefront parameter outputs (Zernike coefficients of the X-ray wavefront phase).…”

“…These studies were made possible due to the single-shot diagnostics of the electron beam implemented in the XFEL. With the recent development of highaccuracy single-shot X-ray wavefront sensors for both soft and hard X-rays at XFELs [21][22][23] and the development of single-shot soft X-ray spectrometers based on off-axis zone plates for spectral measurements 24,25 , X-ray properties can now be characterized routinely. These diagnostic tools enable us to measure the spatial amplitude and phase, as well as the spectral qualities of the X-ray beam and allow us to further combine the X-ray diagnostics data with that of the electron beam diagnostics data into a model based on ANNs.…”

Advancements in Liquid Jet Technology and X-ray Spectroscopy for Understanding Energy Conversion Materials during Operation

“…Depending on the information about the OER which we want to gather, different X-ray spectrometer types can be combined with liquid microjets in the ChemRIXS chamber. − The exchangeable soft X-ray spectrometer units are equipped with a transmission zone plate (TZP), a reflection zone plate (RZP), and a classical grating spectrometer (Figure ). Common for all technical approaches of soft X-ray spectroscopy, the XES and RIXS processes consist of the following steps: The X-ray beam hits the sample (solid/liquid beam). The interaction with the X-rays increases the electron energy in the material/sample under investigation in an element-specific manner. The sample emits photons of specific energy. The emitted photons hit an optical grating and are separated according to their energies. Photons separated according to energy hit the detector. A spectrum of energies can be measured via the distribution of photons on the detector. …”

Supplementary document for Soft X-ray imaging spectroscopy with micrometer resolution - 5000731.pdf

“…Both the linear illumination zone plate (IZP) and the off-axis analyzer zone plate (AZP) are fabricated by high-resolution electron beam lithography, as described in [1,2]. In essence, a hydrogen silsesquioxane film is deposited on a 100 nm silicon nitride (Si 3 N 4 ) membrane via spin-coating.…”