X-ray Nano- and Micro-tomography in an SEM

2013 ◽  
Vol 21 (2) ◽  
pp. 24-28 ◽  
Author(s):  
Bart Pauwels ◽  
Alexander Sasov

X-ray microfocus computer tomography (μ-CT) is a non-destructive experimental technique that reveals the 3D internal microstructure of the sample under study. The experimental set-up consists of an X-ray source, an X-ray detector, and set in between is a sample that is placed on a rotation stage. With this set-up multiple X-ray projection images can be obtained from the sample at different angles. In between the acquisition of two successive images, the sample is rotated over a small angle, typically between 0.2° and 1°. This set of projection images is then used as input for the reconstruction algorithm, which calculates a reconstruction of the internal microstructure of the sample with (sub-) micrometer sensitivity.

2021 ◽  
Vol 11 (4) ◽  
pp. 1446
Author(s):  
Jacopo Orsilli ◽  
Anna Galli ◽  
Letizia Bonizzoni ◽  
Michele Caccia

Among the possible variants of X-Ray Fluorescence (XRF), applications exploiting scanning Macro-XRF (MA-XRF) are lately widespread as they allow the visualization of the element distribution maintaining a non-destructive approach. The surface is scanned with a focused or collimated X-ray beam of millimeters or less: analyzing the emitted fluorescence radiation, also elements present below the surface contribute to the elemental distribution image obtained, due to the penetrative nature of X-rays. The importance of this method in the investigation of historical paintings is so obvious—as the elemental distribution obtained can reveal hidden sub-surface layers, including changes made by the artist, or restorations, without any damage to the object—that recently specific international conferences have been held. The present paper summarizes the advantages and limitations of using MA-XRF considering it as an imaging technique, in synergy with other hyperspectral methods, or combining it with spot investigations. The most recent applications in the cultural Heritage field are taken into account, demonstrating how obtained 2D-XRF maps can be of great help in the diagnostic applied on Cultural Heritage materials. Moreover, a pioneering analysis protocol based on the Spectral Angle Mapper (SAM) algorithm is presented, unifying the MA-XRF standard approach with punctual XRF, exploiting information from the mapped area as a database to extend the comprehension to data outside the scanned region, and working independently from the acquisition set-up. Experimental application on some reference pigment layers and a painting by Giotto are presented as validation of the proposed method.


2013 ◽  
Vol 21 (1) ◽  
pp. 1-4 ◽  
Author(s):  
Hiroyuki Kishimoto ◽  
Yuya Shinohara ◽  
Yoshio Suzuki ◽  
Akihisa Takeuchi ◽  
Naoto Yagi ◽  
...  

A pinhole-type two-dimensional ultra-small-angle X-ray scattering set-up at a so-called medium-length beamline at SPring-8 is reported. A long sample-to-detector distance, 160.5 m, can be used at this beamline and a small-angle resolution of 0.25 µm−1was thereby achieved at an X-ray energy of 8 keV.


2010 ◽  
pp. 109-117 ◽  
Author(s):  
Neda Motchurova-Dekova ◽  
David Harper

Synchrotron radiation X-ray tomographic microscopy (SRXTM) is a non-destructive technique for the investigation and visualization of the internal features of solid opaque objects, which allows reconstruction of a complete three-dimensional image of internal structures by recording of the differences in the effects on the passage of waves of energy reacting with those structures. Contrary to X-rays, produced in a conventional X-ray tube, the intense synchrotron light beams are sharply focused like a laser beam. We report encouraging results from the use of SRXTM for purely taxonomic purposes in brachiopods: an attempt to find a non-destructive and more efficient alternative to serial sectioning and several other methods of dissection together with the non-destructive method of X-ray computerised micro-tomography. Two brachiopod samples were investigated using SRXTM. In ?Rhynchonella? flustracea it was possible to visualise the 3D shape of the crura and dental plates. In Terebratulina imbricata it was possible to reveal the form of the brachidium. It is encouraging that we have obtained such promising results using SRXTM with our very first two fortuitous samples, which had respectively fine-grained limestone and marl as infilling sediment, in contrast to the discouraging results communicated to us by some colleagues who have tested specimens with such infillings using X-ray micro-tomography. In future the holotypes, rare museum specimens or delicate Recent material may be preferentially subjected to this mode of analysis.


2008 ◽  
Vol 28 (6) ◽  
pp. 1079-1084
Author(s):  
陈欣 Chen Xin ◽  
孙怡 Sun Yi ◽  
朱佩平 Zhu Peiping

2010 ◽  
Vol 30 (2) ◽  
pp. 421-427 ◽  
Author(s):  
李镜 Li Jing ◽  
刘文杰 Liu Wenjie ◽  
朱佩平 Zhu Peiping ◽  
孙怡 Sun Yi

2014 ◽  
Vol 4 (1) ◽  
Author(s):  
T. Sibillano ◽  
L. De Caro ◽  
D. Altamura ◽  
D. Siliqi ◽  
M. Ramella ◽  
...  

Author(s):  
P. J. Webster ◽  
Z. Chen ◽  
D. J. Hughes ◽  
A. Steuwer ◽  
B. Malard ◽  
...  

Large Central Scientific Facilities such as the ESRF (the European Synchrotron Radiation Facility) and ILL (the European centre for neutron research), were set up to provide scientists with the advanced facilities they need to exploit neutron and synchrotron X-ray beams for scientific research. Engineers also conduct research at these Facilities, but this is less common as most practicing engineers generally have little or no knowledge of neutron or X-ray scattering, or of their considerable potential for engineering research, model validation, material development and for fatigue and failure analysis. FaME38 is the new joint support Facility for Materials Engineering, located at ILL-ESRF, set up to encourage and to facilitate engineering research by engineers at these facilities. It provides a technical and knowledge centre, a materials support laboratory, and the additional equipment and resources that academic and industrial engineers need for materials engineering research to become practicable, efficient and routine. It enables engineers to add the most advanced scientific diffraction and imaging facilities to their portfolio of diagnostic tools. These include non-destructive internal and through-surface strain scanning, phase analysis, radiography and tomography of engineering components. Synchrotron X-ray and neutron diffraction strain mapping is particularly suited for the rigorous experimental, non-destructive, validation of Finite Element and other computer model codes used to predict residual stress fields that are critical to the performance and lifetimes of engineering components. This paper discusses the FaME38 facility and demonstrates its utility in gaining fundamental insight into mechanical engineering problems through examples, including studies of railway rails, welds and peened surfaces that demonstrate the potential of neutron of synchrotron X-ray strain scanning for the determination of residual stress fields in a variety of engineering materials and critical components.


1999 ◽  
Vol 5 (S2) ◽  
pp. 940-941
Author(s):  
Shih Ang ◽  
Wang Ge ◽  
Cheng Ping-Chin

Due to the penetration ability and absorption contrast mechanism, cone-beam X-ray microtomography is a powerful tool in studying 3D microstructures in opaque specimens. In contrast to the conventional parallel and fan-beam geometry, the cone-beam tomography set up is highly desirable for faster data acquisition, build-in magnification, better radiation utilization and easier hardware implementation. However, the major draw back of the cone-beam reconstruction is its computational complexity. In an effort to maximize the reconstruction speed, we have developed a generalized Feldkamp cone-beam reconstruction algorithm to optimize the reconstruction process. We report here the use of curved voxels in a cylindrical coordinate system and mapping tables to further improve the reconstruction efficiency.The generalized Feldkamp cone-beam image reconstruction algorithm is reformulated utilizing mapping table in the discrete domain as: , where .


Sign in / Sign up

Export Citation Format

Share Document