Publications by authors named "E Prat"
X-ray free-electron lasers (FELs) are modern research tools with applications in multiple scientific fields. Standard x-ray FEL pulses are produced by the self-amplified spontaneous emission (SASE) mechanism. SASE-FEL pulses have high power, short duration, and excellent transverse coherence but exhibit poor temporal coherence with power and spectral profiles consisting of multiple randomly distributed spikes.
View Article and Find Full Text PDFThe ability to freely control the polarization of X-rays enables measurement techniques relying on circular or linear dichroism, which have become indispensable tools for characterizing the properties of chiral molecules or magnetic structures. Therefore, the demand for polarization control in X-ray free-electron lasers is increasing to enable polarization-sensitive dynamical studies on ultrafast time scales. The soft X-ray branch Athos of SwissFEL was designed with the aim of providing freely adjustable and arbitrary polarization by building its undulator solely from modules of the novel Apple X type.
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- ClC-K/barttin channels play a vital role in chloride transport in the kidneys and inner ear, and mutations in their genes can lead to Bartter's syndrome.
- Research shows that a specific amino acid change in barttin enhances ClC-K currents, but the exact mechanism and significance in living organisms is still unclear.
- Experiments using Xenopus oocytes and mice indicate that mutations in a particular YxxØ motif on barttin can increase its stability at the plasma membrane and improve function, although these mutations do not change overall protein expression levels under certain diet conditions.
This article presents a demonstration of the improved performance of an X-ray free-electron laser (FEL) using the optical klystron mechanism and helical undulator configuration, in comparison with the common planar undulator configuration without optical klystron. The demonstration was carried out at Athos, the soft X-ray beamline of SwissFEL. Athos has variable-polarization undulators, and small magnetic chicanes placed between every two undulators to fully exploit the optical klystron.
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- - A novel method for time-resolved X-ray absorption near edge structure (XANES) spectroscopy is introduced, allowing for quicker data collection and smaller sample sizes, which improves the efficiency of analyzing numerous samples.
- - This technique utilizes large bandwidth free electron laser pulses to gather laser-excited XANES spectra in transmission mode, employing a special beam-splitting configuration for simultaneous measurements.
- - Testing on a liquid solution of ammonium iron(III) oxalate demonstrates significant advancements in speed and spectral resolution, enabling rapid creation of extensive 2-D spectral-time maps compared to older methods.