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Grating monochromators are crucial optical elements in soft X-ray free-electron laser (XFEL) beamlines. Accurately evaluating the properties of grating monochromators with near-realistic XFEL pulse is of paramount importance. In this study, we utilize the start-to-end pulse propagation method to conduct a characterization of grating monochromator performance at the FEL-1 beamline of SFEL. The primary focuses include evaluating the monochromator's resolving power, assessing the impact of longitudinal source jitter on resolving power, analyzing diffraction effects due to grating's limited aperture and investigating the influence of thermal deformation. The novelty of this research lies in the direct use of FEL pulse propagation, providing simulation results that are more reliable than those obtained using Gaussian sources. The simulations reveal that the resolving power of the monochromator is significantly influenced by the aforementioned factors, highlighting the importance of considering real FEL beam characteristics in the design and evaluation of grating monochromators for FEL applications.
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http://dx.doi.org/10.1107/S1600577525006472 | DOI Listing |
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC12416410 | PMC |
Magn Reson Med
September 2025
Laboratorio de Procesado de Imagen (LPI), Universidad de Valladolid, Valladolid, Spain.
Purpose: (a) To design a methodology for drawing random samples of any Ensemble Average Propagator (EAP) (b) to modify the KomaMRI simulator to accommodate them as realistic spin movements to simulate diffusion MRI (dMRI) and (c) to compare these simulations with those based on the Diffusion Tensor (DT) model.
Theory And Methods: The rejection method is used for random sampling of EAPs: starting from a probability law that is easily sampled, and whose density function wraps the target EAP, samples are accepted when they lie inside the targeted region. This is used to sample the EAP as described by Mean Apparent Propagator MRI (MAP-MRI) and in Spherical Convolution (SC) based on Spherical Harmonics (SH).
Sci Rep
September 2025
Department of Mathematics, Wollega University, 395, Nekemte, Ethiopia.
Research on [Formula: see text]-symmetry and spontaneous symmetry breaking captivates contemporary scholars due to its extensive applicability in several fields, including microwave propagation and nonlinear optics. This article studies the nonlocal complex short pulse (NL-CSP) equation in which we discuss how under certain symmetry reduction general complex short pulse equation turns into NL-CSP equation. We construct the binary Darboux transformation for the reverse space-time NL-CSP equation and derive its quasi-grammian solutions.
View Article and Find Full Text PDFFront Physiol
August 2025
Laboratory of Mathematical Modeling of Physiological Processes, Nalecz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, Warsaw, Poland.
Objective: Multi-limb oscillometric cuff measurements can be used for estimating various vascular parameters and evaluating side differences in arterial pulse waveforms. In this study, we conduct an investigation to evaluate the potential impact of such measurements on hemodynamics.
Methods: We employed a 0-1D model of pulse wave propagation to examine the relationship between different levels of oscillometric cuff pressure applied simultaneously at multiple sites (right above the wrists and/or ankles) and the resulting changes in blood pressure and flow at selected sites in the vascular system, assuming the absence of cardiovascular regulatory mechanisms.
Proc IEEE Int Symp Appl Ferroelectr
September 2024
Department of Biomedical Engineering, New York City, USA.
Arterial stiffness is a key predictor of cardiovascular mortality. This study utilizes ultrasound-based Pulse Wave Imaging (PWI) and Vector Flow Imaging (VFI) to track vessel wall displacement caused by arterial pulse wave propagation and blood flow velocity at a high frame rate (3.3 kHz) to estimate localized arterial wall stiffness through an Inverse problem setting.
View Article and Find Full Text PDFMed Phys
September 2025
Department of Biomedical Engineering, University of Michigan, Ann Arbor, Michigan, USA.
Background: In clinical radiation therapy (RT), accurately quantifying the delivered radiation dose to the targeted tumors and surrounding tissues is essential for evaluating treatment outcomes. Ionizing radiation acoustic imaging (iRAI), a novel passive and non-invasive imaging technique, has the potential to provide real-time in vivo radiation dose mapping during RT. However, current iRAI technology does not account for spatial variations in the detection sensitivity of the ultrasound transducer used to capture the iRAI signals, leading to significant errors in dose mapping.
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