检索结果-内蒙古大学图书馆

advances in computational methods for x-ray optics VI 2023

ISBN: (纸本)9781510666085

The proceedings contain 12 papers. The topics discussed include: FOCUS: current status and future perspectives;new wavefront split propagator in SRW code and its application in simulation of high-resolution Fresnel zone plate;comparing coherent mode decomposition methods for undulator radiation in modern synchrotron light sources;exploring the use of x-ray adaptive optics in soft x-ray grating monochromators with wavefront propagation simulations;SimEx-lite: easy access to start-to-end simulation for experiments at advanced light sources;transverse coherence properties and propagation of x-ray radiation from spontaneous and free-electron laser sources;GPU accelerated simulations of time-dependent coherent x-ray scattering experiments;and latent Bayesian optimization for the autonomous alignment of synchrotron beamlines.

关键词：

来源：评论

学校读者我要写书评

暂无评论

advances in computational methods for x-ray optics V

Advances in Computational Methods for X-Ray Optics V

引用

advances in computational methods for x-ray optics V 2020

ISBN: (纸本)9781510637924

The proceedings contain 24 papers. The topics discussed include: Mcxtrace anno 2020 - complex sample geometries and GPU acceleration;WISER wavefront propagation simulation code: advances and applications;reduced model representation of x-ray transport suitable for beamline control;perturbation perspective of partial coherence discussion on imperfect x-ray optical elements;reconstruction of offsets of an electron gun using deep learning and an optimization algorithm;CPU and memory efficient coherent mode decomposition for the partially coherent x-ray simulations;parallel performance of 'Synchrotron Radiation Workshop' code: partially coherent calculations for storage rings and time-dependent calculations for xFELs;and recent developments in x-ray lens modeling with SRW.

关键词：

来源：评论

学校读者我要写书评

暂无评论

Selected advances in small-angle scattering and applications they serve in manufacturing, energy and climate change

引用

JOURNAL OF APPLIED CRYSTALLOGRAPHY 2023年第Part3期56卷 787-800页

作者： Allen, Andrew J. Natl Inst Stand & Technol Mat Measurement Sci Div 100 Bur Dr Gaithersburg MD 20899 USA

Innovations in small-angle x-ray and neutron scattering (SAxS and SANS) at major x-ray and neutron facilities offer new characterization tools for researching materials phenomena relevant to advanced applications. For SAxS, the new generation of diffraction-limited storage rings, incorporating multi-bend achromat concepts, dramatically decrease electron beam emittance and significantly increase x-ray brilliance over previous third-generation sources. This results in intense x-ray incident beams that are more compact in the horizontal plane, allowing significantly improved spatial resolution, better time resolution, and a new era for coherent-beam SAxS methods such as x-ray photon correlation spectroscopy. Elsewhere, x-ray free-electron laser sources provide extremely bright, fully coherent, x-ray pulses of <100 fs and can support SAxS studies of material processes where entire SAxS data sets are collected in a single pulse train. Meanwhile, SANS at both steady-state reactor and pulsed spallation neutron sources has significantly evolved. Developments in neutron optics and multiple detector carriages now enable data collection in a few minutes for materials characterization over nanometre-to-micrometre scale ranges, opening up real-time studies of multi-scale materials phenomena. SANS at pulsed neutron sources is becoming more integrated with neutron diffraction methods for simultaneous structure characterization of complex materials. In this paper, selected developments are highlighted and some recent state-of-theart studies discussed, relevant to hard matter applications in advanced manufacturing, energy and climate change.

关键词： small-angle x-ray scattering small-angle neutron scattering microstructure characterization advanced manufacturing energy applications carbon dioxide reduction

来源：评论

学校读者我要写书评

暂无评论

Transverse coherence properties and propagation of x-ray radiation from spontaneous and free-electron laser sources 6

Transverse coherence properties and propagation of X-ray rad...

引用

advances in computational methods for x-ray optics VI 2023

作者： Trebushinin, Andrei Siano, Mirko Serkez, Svitozar Geloni, Gianluca A. European XFEL GmbH Holzkoppel 4 Schenefeld22869 Germany Dipartimento di Fisica Università degli Studi di Milano Via G. Celoria 16 Milan20133 Italy

ISBN: (纸本)9781510666085

In this contribution we discuss two major classes of transversely partially coherent x-ray sources: undulators in storage rings and SASE free-electron lasers. We address similarities and differences in terms of statistical and coherence properties, highlighting their relation with state-of-the-art numerical methods used to simulate the emitted wavefronts and their propagation down a beamline. We also report on recent developments based on simplifying analytical approximations and the use of physical models, leading to fast techniques with improved numerical efficiency particularly suitable for realistic description of spontaneous emission in undulator sources. © 2023 SPIE. All rights reserved.

关键词： Free electron lasers

来源：评论

学校读者我要写书评

暂无评论

Exploring the use of x-ray adaptive optics in soft x-ray grating monochromators with wavefront propagation simulations 6

Exploring the use of x-ray adaptive optics in soft x-ray gra...

引用

advances in computational methods for x-ray optics VI 2023

作者： Luna, Paola Wojdyla, Antoine Advanced Light Source Lawrence Berkeley National Laboratory BerkeleyCA94710 United States

ISBN: (纸本)9781510666085

We have used coherent wavefront propagation simulation (in python) to demonstrate that the current generation of bimorph deformable mirrors can be used as a pre-mirror in a grating monochromator to improve their performance and expand their range of application. We have used influence functions acquired from an existing deformable mirror to make sure the wavefront correction can be achieved in actual implementations and establish a set of specification requirements for such mirrors (number of actuators, precision, distance between the optical elements.) We also discuss the relative benefits of positioning the adaptive mirror before or after the grating, and we show that given typical beamline designs and undulator bandwidth, such a solution is viable to achieve wavefront correction on a dispersed beam and achieve photon energy high resolution to go beyond the limitations of state-of-the-art manufacturing capabilities of gratings. © 2023 SPIE. All rights reserved.

关键词： Adaptive optics

来源：评论

学校读者我要写书评

暂无评论

Machine Learning Based Alignment For LCLS-II-HE optics 6

Machine Learning Based Alignment For LCLS-II-HE Optics

引用

advances in computational methods for x-ray optics VI 2023

作者： Mishra, Aashwin Brennan, Nicholas Huang, Tianyu Jaquith, Jason Yavaş, Hasan Seaberg, Matthew SLAC National Accelerator Laboratory Menlo ParkCA94025 United States

ISBN: (纸本)9781510666085

The hard x-ray instruments at the Linac Coherent Light Source are in the design phase for upgrades that will take full advantage of the high repetition rates that will become available with LCLS-II-HE. The current x-ray Correlation Spectroscopy instrument will be converted to the Dynamic x-ray Scattering instrument, and will feature a meV-scale high-resolution monochromator at its front end with unprecedented coherent flux. With the new capability come many engineering and design challenges, not least of which is the sensitivity to long-term drift of the optics. With this in mind, we have estimated the system tolerance to angular drift and vibration for all the relevant optics (∼10 components) in terms of how the central energy out of the monochromator will be affected to inform the mechanical design. Additionally, we have started planning for methods to correct for such drifts using available (both invasive and non-invasive) x-ray beam diagnostics. In simulations, we have demonstrated the ability of trained Machine Learning models to correct misalignments to maintain the desired central energy and optical axis within the necessary tolerances. Additionally, we exhibit the use of Bayesian Optimization to minimize the impact of thermal deformations of crystals as well as beam alignment from scratch. The initial results are very promising and efforts to further extend this work are ongoing. © 2023 SPIE. All rights reserved.

关键词： Electrons

来源：评论

学校读者我要写书评

暂无评论

AI-driven real-time optics control system to achieve aberration-free coherent wavefronts at 4th-generation synchrotron radiation and free electron laser beamlines 6

AI-driven real-time optics control system to achieve aberrat...

引用

advances in computational methods for x-ray optics VI 2023

作者： Rebuffi, Luca Shi, xianbo Zhang, Runyu Highland, Matthew J. Frith, Matthew G. Cha, Wonsuk Harder, Ross J. Kandel, Saugat Cherukara, Mathew J. Assoufid, Lahsen Advanced Photon Source Argonne National Laboratory ArgonneIL60439 United States

ISBN: (纸本)9781510666085

In experiments utilizing 4th-generation synchrotron radiation and free electron laser (FEL) beamlines, a primary challenge for x-ray optical elements is to achieve and maintain high-intensity focused x-ray beams with near-perfect wavefront quality and high stability. These optical elements inherently demand more stringent specifications than those for other applications because of the shorter wavelength and the ultra-small emittance of the radiation beams from these sources. Coherent photons from diffraction-limited light sources further underscore the necessity for a controlled wavefront. Maintaining a uniform wavefront is crucial for phase-sensitive imaging techniques and for various coherent x-ray scattering experiments, such as tomography, coherent x-ray diffraction imaging, x-ray photon correlation spectroscopy and coherent surface scattering imaging. Therefore, x-ray optics must be manufactured close to ideal mathematical shapes, automatically align and focus beams according to experimental needs, and offer real-time correction to wavefront deformations. At the Advanced Photon Source (APS), we have demonstrated the application of a neural network model to automatically control deformable mirrors and the use of Bayesian optimization with Gaussian processes to align and stabilize focusing optical systems. © 2023 SPIE. All rights reserved.

关键词： Synchrotron radiation

来源：评论

学校读者我要写书评

暂无评论

Comparing coherent mode decomposition methods for undulator radiation in modern synchrotron light sources 6

Comparing coherent mode decomposition methods for undulator ...

引用

advances in computational methods for x-ray optics VI 2023

作者： Chubar, Oleg Tanaka, Takashi Li, Ruizi Brookhaven National Laboratory UptonNY11973 United States RIKEN SPring-8 Center Koto 1-1-1 Hyogo Sayo679-5148 Japan

ISBN: (纸本)9781510666085

We compare the general coherent mode decomposition (CMD) method implemented in SRW code and the method making use of Hermite-Gaussian functions implemented in SPECTRA code, both methods being applied to partially coherent undulator radiation (UR). The comparison is made in terms of modes required for the same accuracy of presentation of 4D cross spectral density and Wigner function of UR for the same electron beam and undulator systems (corresponding to modern high-brightness light sources – currently operating NSLS-II and the planned upgrade of SPring-8). We show that, even though the pre-defined orthogonal analytical functions are not the exact eigenmodes of the partially coherent UR, their use can be perfectly justified in many cases for the UR, especially when limited computational resources are available for performing the numerical decomposition. Before analyzing the CMD results, we also illustrate excellent agreement between UR characteristics computed with SPECTRA and with SRW. All the presented comparisons, and the agreements found, confirm the validity of methods used by the codes and accuracy of their results. © 2023 SPIE. All rights reserved.

关键词： Wigglers

来源：评论

学校读者我要写书评

暂无评论

GPU Accelerated Simulations of Time-dependent Coherent x-ray Scattering Experiments 6

GPU Accelerated Simulations of Time-dependent Coherent X-ray...

引用

advances in computational methods for x-ray optics VI 2023

作者： Goel, Himanshu Chubar, Oleg Wiegart, Lutz Fluerasu, Andrei Li, Ruizi He, An Rakitin, Max Lin, Meifeng Moeller, Paul Nagler, Robert Stony Brook University Stony BrookNY United States Brookhaven National Laboratory UptonNY United States RadiaSoft LLC BoulderCO United States

ISBN: (纸本)9781510666085

Detailed physical optics simulations of beamlines and experiments offer great value towards efficiently utilizing light source facilities. They make it possible to study their predicted behaviors under configurations which can be controlled more precisely than in physical experiments. Synchrotron Radiation Workshop (SRW) is a state-of-the-art software package for such simulations. Through its Python-based interface and browser-based interface Sirepo, SRW supports the definition of detailed optical schemes with many types of optical elements, and the simulation of radiation propagation through them. SRW has been mainly focused on CPU-based calculations;however, due to many of the operations being embarrassingly parallel, there is significant potential for accelerating these calculations using general-purpose GPU computation. In this work, the application of GPU accelerated computing to SRW for accelerating time-dependent coherent x-ray scattering experiments is discussed. A detailed simulation of a typical x-ray Photon Correlation Spectroscopy experiment for characterizing the dynamics of a colloidal sample was performed. Large improvements in simulation speed were demonstrated by converting the radiation propagation operations for the associated optical elements to use GPU computation. Combined with coherent mode decomposition, this resulted in a qualitative leap forward in the calculation speed and level of detail at which similar partially coherent scattering experiments can be simulated. These improvements have wide-ranging applications, such as assisting in the development of improved data processing methods and allowing for more detailed analysis of proposed experiments before using beam time. © 2023 SPIE. All rights reserved.

关键词： Synchrotron radiation

来源：评论

学校读者我要写书评

暂无评论

Multilayer coating design methods for a high-energy x-ray imaging optic with complex design requirements 27

Multilayer coating design methods for a high-energy x-ray im...

引用

Conference on advances in x-ray/EUV optics and Components xVII

作者： Walton, Chris C. Kozioziemski, Bernard Fein, Jeffrey R. Romaine, Suzanne E. Vogel, Julia K. Lawrence Livermore Natl Lab Livermore CA 94550 USA Sandia Natl Labs Albuquerque NM 87185 USA Harvard & Smithsonian Ctr Astrophys Cambridge MA 02138 USA Univ Zaragoza Dept Theoret Phys Zaragoza Spain

ISBN: (纸本)9781510654655;9781510654648

Imaging of x-rays with energies >15 keV is a necessity for several applications in high-energy density physics experiments. Multilayer-coated, Wolter-type glancing-incidence optics offer higher collection efficiency than pinhole cameras or Kirkpatrick-Baez style mirrors, and can achieve spatial resolution of 10-100um over 1-8 mm fields of view with throughput similar to 1-10%. Designing the multilayer coating is a complex optimization problem, involving multiple tradeoffs. A narrow energy bandwidth (similar to 1keV) is desirable to exclude background, but a broad angular acceptance is desirable for the optic to image a large field (similar to 1-8 mm). A Wolter optic's net reflectivity is two-bounce R-2 = R-1*R-2 for a wide range of pairs of incidence angles theta(1), theta(2). In addition, the multilayer coating can be modified in several ways, such as varying the period thickness through the stack, and along the length of the optic. Parallelized searches using ordinary gradient-descent and Markov-Chain Monte Carlo (MCMC) have been applied to design an optic to image Z-pinch plasmas on the Z Machine at Sandia National Laboratories. methods are tested to design an appropriate cost function for this search, and to reduce computational cost to search the parameter space efficiently.

关键词： x-ray optics multilayer coatings plasma diagnostics high energy density optimization

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：