Fast reconstruction tools for ptychography at Sirius, the fourth-generation Brazilian synchrotron

2020 ◽  
Vol 53 (6) ◽  
pp. 1550-1558
Author(s):  
Giovanni L. Baraldi ◽  
Carlos S. B. Dias ◽  
Francisco M. C. Silva ◽  
Hélio C. N. Tolentino ◽  
Eduardo X. Miqueles

Described here are image reconstruction optimizations for ptychographic coherent X-ray scattering data and X-ray fluorescence, which have been developed for the new fourth-generation synchrotron light source, Sirius, at the Brazilian Synchrotron Light Laboratory. The optimization strategy has been applied to the standard experimental strategy for ptychographic and fluorescence experiments on the Carnaúba beamline which involves the use of high-speed continuous scans (fly scans) for a fast acquisition time over large areas through the use of a newly proposed trajectory named the alternating linear trajectory. The scientific computing developments presented here target an efficient use of graphical processing units (GPUs) to the point where large fly-scan acquisitions can be processed in real time on a local high-performance computer. Some optimizations involving a custom fast Fourier transform implementation and use of mixed precision can be applied to other algorithms and phase-retrieval techniques, and therefore this work provides a general optimization scheme. Finally, the optimization strategy presented here has improved performance by a factor of ∼2.5 times faster when compared with non-optimized GPU implementations.

Author(s):  
Auclair Gilles ◽  
Benoit Danièle

During these last 10 years, high performance correction procedures have been developed for classical EPMA, and it is nowadays possible to obtain accurate quantitative analysis even for soft X-ray radiations. It is also possible to perform EPMA by adapting this accurate quantitative procedures to unusual applications such as the measurement of the segregation on wide areas in as-cast and sheet steel products.The main objection for analysis of segregation in steel by means of a line-scan mode is that it requires a very heavy sampling plan to make sure that the most significant points are analyzed. Moreover only local chemical information is obtained whereas mechanical properties are also dependant on the volume fraction and the spatial distribution of highly segregated zones. For these reasons we have chosen to systematically acquire X-ray calibrated mappings which give pictures similar to optical micrographs. Although mapping requires lengthy acquisition time there is a corresponding increase in the information given by image anlysis.


Author(s):  
Marc H. Peeters ◽  
Max T. Otten

Over the past decades, the combination of energy-dispersive analysis of X-rays and scanning electron microscopy has proved to be a powerful tool for fast and reliable elemental characterization of a large variety of specimens. The technique has evolved rapidly from a purely qualitative characterization method to a reliable quantitative way of analysis. In the last 5 years, an increasing need for automation is observed, whereby energy-dispersive analysers control the beam and stage movement of the scanning electron microscope in order to collect digital X-ray images and perform unattended point analysis over multiple locations.The Philips High-speed Analysis of X-rays system (PHAX-Scan) makes use of the high performance dual-processor structure of the EDAX PV9900 analyser and the databus structure of the Philips series 500 scanning electron microscope to provide a highly automated, user-friendly and extremely fast microanalysis system. The software that runs on the hardware described above was specifically designed to provide the ultimate attainable speed on the system.


2001 ◽  
Author(s):  
Karen K. Siu ◽  
Andrei Y. Nikulin ◽  
James Hester ◽  
Andreas K. Freund ◽  
Tetsuya Ishikawa

2018 ◽  
Vol 25 (3) ◽  
pp. 801-807 ◽  
Author(s):  
Tunhe Zhou ◽  
Hongchang Wang ◽  
Thomas Connolley ◽  
Steward Scott ◽  
Nick Baker ◽  
...  

The high flux of the white X-ray beams from third-generation synchrotron light sources can significantly benefit the development of high-speed X-ray imaging, but can also bring technical challenges to existing X-ray imaging systems. One prevalent problem is that the image quality deteriorates because of dust particles accumulating on the scintillator screen during exposure to intense X-ray radiation. Here, this problem has been solved by embedding the scintillator in a flowing inert-gas environment. It is also shown that the detector maintains the quality of the captured images even after days of X-ray exposure. This modification is cost-efficient and easy to implement. Representative examples of applications using the X-ray imaging system are also provided, including fast tomography and multimodal phase-contrast imaging for biomedical and geological samples.


1999 ◽  
Vol 5 (S2) ◽  
pp. 252-253
Author(s):  
J. A. Sutliff ◽  
S. D. Sitzman

This work describes an investigation of the microstructure of a γ/γ' Ni-base superalloy using the automated Electron BackScattering Pattern (EBSP) technique with simultaneous energy dispersive x-ray spectrometry (EDS). The goal of the investigation was to determine if EDS measurements necessary to discriminate γ' from γ' could be obtained when acquired simultaneously with a normal, high speed automated EBSP scan. The acquisition conditions that impact the EDS collection are: surface tilted ∼70 degrees from the beam axis, 70mm spectrometer to specimen distance limited by interference from the EBSP detector and approximately 300 ms available acquisition time.Thermo-mechanical processing of superalloys can produce coarse γ' that appears both within grains and at grain boundaries. In some conditions, the coarse γ' may be as large as many γ grains. As the crystal structure of γ and γ' are very similar, it is not possible to discriminate between the two phases using typical EBSP analysis. However, one needs to discriminate these phases in order to measure properties of the γ matrix such as texture and grain size.


2013 ◽  
Vol 46 (6) ◽  
pp. 1781-1795 ◽  
Author(s):  
Slim T. Chourou ◽  
Abhinav Sarje ◽  
Xiaoye S. Li ◽  
Elaine R. Chan ◽  
Alexander Hexemer

This article describes the development of a flexible grazing-incidence small-angle X-ray scattering (GISAXS) simulation code in the framework of the distorted wave Born approximation that effectively utilizes the parallel processing power provided by graphics processors and multicore processors. The code, entitledHigh-Performance GISAXS, computes the GISAXS image for any given superposition of user-defined custom shapes or morphologies in a material and for various grazing-incidence angles and sample orientations. These capabilities permit treatment of a wide range of possible sample structures, including multilayered polymer films and nanoparticles on top of or embedded in a substrate or polymer film layers. In cases where the material displays regions of significant refractive index contrast, an algorithm has been implemented to perform a slicing of the sample and compute the averaged refractive index profile to be used as the reference geometry of the unperturbed system. A number of case studies are presented, which demonstrate good agreement with the experimental data for a variety of polymer and hybrid polymer/nanoparticle composite materials. The parallelized simulation code is well suited for addressing the analysis efforts required by the increasing amounts of GISAXS data being produced by high-speed detectors and ultrafast light sources.


2020 ◽  
Vol 53 (6) ◽  
pp. 1444-1451
Author(s):  
Maik Kahnt ◽  
Simone Sala ◽  
Ulf Johansson ◽  
Alexander Björling ◽  
Zhimin Jiang ◽  
...  

Ptychographic X-ray computed tomography is a quantitative three-dimensional imaging technique offered to users of multiple synchrotron radiation sources. Its dependence on the coherent fraction of the available X-ray beam makes it perfectly suited to diffraction-limited storage rings. Although MAX IV is the first, and so far only, operating fourth-generation synchrotron light source, none of its experimental stations is currently set up to offer this technique to its users. The first ptychographic X-ray computed tomography experiment has therefore been performed on the NanoMAX beamline. From the results, information was gained about the current limitations of the experimental setup and where attention should be focused for improvement. The extracted parameters in terms of scanning speed, size of the imaged volume and achieved resolutions should provide a baseline for future users designing nano-tomography experiments on the NanoMAX beamline.


2018 ◽  
Vol 51 (5) ◽  
pp. 055601 ◽  
Author(s):  
Margie P Olbinado ◽  
Valentina Cantelli ◽  
Olivier Mathon ◽  
Sakura Pascarelli ◽  
Joerg Grenzer ◽  
...  

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