scholarly journals High-speed X-ray imaging of a ball impacting on loose sand

2015 ◽  
Vol 777 ◽  
pp. 690-706 ◽  
Author(s):  
Tess Homan ◽  
Rob Mudde ◽  
Detlef Lohse ◽  
Devaraj van der Meer

When a ball is dropped in fine very loose sand, a splash and subsequently a jet are observed above the bed, followed by a granular eruption. To directly and quantitatively determine what happens inside the sand bed, high-speed X-ray tomography measurements are carried out in a custom-made set-up that allows for imaging of a large sand bed at atmospheric pressures. Herewith, we show that the jet originates from the pinch-off point created by the collapse of the air cavity formed behind the penetrating ball. Subsequently, we measure how the entrapped air bubble rises through the sand, and show that this is consistent with bubbles rising in continuously fluidized beds. Finally, we measure the packing fraction variation throughout the bed. From this we show that there is (i) a compressed area of sand in front of and next to the ball while the ball is moving down, (ii) a strongly compacted region at the pinch-off height after the cavity collapse and (iii) a relatively loosely packed centre in the wake of the rising bubble.

2020 ◽  
Author(s):  
Emilio M. Escauriza ◽  
Joao P. Duarte ◽  
David J. Chapman ◽  
Lukasz Farbaniec ◽  
John C. Jonsson ◽  
...  

Author(s):  
Andreas Kopmann ◽  
Suren Chilingaryan ◽  
Matthias Vogelgesang ◽  
Timo Dritschler ◽  
Andrey Shkarin ◽  
...  
Keyword(s):  
X Ray ◽  

2017 ◽  
Vol 24 (6) ◽  
pp. 1283-1295 ◽  
Author(s):  
Tomáš Faragó ◽  
Petr Mikulík ◽  
Alexey Ershov ◽  
Matthias Vogelgesang ◽  
Daniel Hänschke ◽  
...  

An open-source framework for conducting a broad range of virtual X-ray imaging experiments,syris, is presented. The simulated wavefield created by a source propagates through an arbitrary number of objects until it reaches a detector. The objects in the light path and the source are time-dependent, which enables simulations of dynamic experiments,e.g.four-dimensional time-resolved tomography and laminography. The high-level interface ofsyrisis written in Python and its modularity makes the framework very flexible. The computationally demanding parts behind this interface are implemented in OpenCL, which enables fast calculations on modern graphics processing units. The combination of flexibility and speed opens new possibilities for studying novel imaging methods and systematic search of optimal combinations of measurement conditions and data processing parameters. This can help to increase the success rates and efficiency of valuable synchrotron beam time. To demonstrate the capabilities of the framework, various experiments have been simulated and compared with real data. To show the use case of measurement and data processing parameter optimization based on simulation, a virtual counterpart of a high-speed radiography experiment was created and the simulated data were used to select a suitable motion estimation algorithm; one of its parameters was optimized in order to achieve the best motion estimation accuracy when applied on the real data.syriswas also used to simulate tomographic data sets under various imaging conditions which impact the tomographic reconstruction accuracy, and it is shown how the accuracy may guide the selection of imaging conditions for particular use cases.


JOM ◽  
2020 ◽  
Vol 73 (1) ◽  
pp. 201-211 ◽  
Author(s):  
Benjamin Gould ◽  
Sarah Wolff ◽  
Niranjan Parab ◽  
Cang Zhao ◽  
Maria Cinta Lorenzo-Martin ◽  
...  

1999 ◽  
Vol 46 (3) ◽  
pp. 232-236 ◽  
Author(s):  
V.V. Nagarkar ◽  
S.V. Tipnis ◽  
T.K. Gupta ◽  
S.R. Miller ◽  
V.B. Gaysinskiy ◽  
...  

2019 ◽  
Vol 26 (5) ◽  
pp. 1631-1637
Author(s):  
Honglan Xie ◽  
Hongxin Luo ◽  
Guohao Du ◽  
Chengqiang Zhao ◽  
Wendong Xu ◽  
...  

Indirect X-ray imaging detectors consisting of scintillator screens, long-working-distance microscope lenses and scientific high-speed complementary metal-oxide semiconductor (CMOS) cameras are usually used to realize fast X-ray imaging with white-beam synchrotron radiation. However, the detector efficiency is limited by the coupling efficiency of the long-working-distance microscope lenses, which is only about 5%. A long-working-distance microscope lenses system with a large numerical aperture (NA) is designed to increase the coupling efficiency. It offers an NA of 0.5 at 8× magnification. The Mitutoyo long-working-distance microscope lenses system offers an NA of 0.21 at 7.5× magnification. Compared with the Mitutoyo system, the developed long-working-distance microscope lenses system offers about twice the NA and four times the coupling efficiency. In the indirect X-ray imaging detector, a 50 µm-thick LuAG:Ce scintillator matching with the NA, and a high-speed visible-light CMOS FastCAM SAZ Photron camera are used. Test results show that the detector realized fast X-ray imaging with a frame rate of 100000 frames s−1 and fast X-ray microtomography with a temporal sampling rate up to 25 Hz (25 tomograms s−1).


2020 ◽  
Vol 60 ◽  
pp. 470-480
Author(s):  
Jannik Lind ◽  
Florian Fetzer ◽  
Christian Hagenlocher ◽  
David Blazquez-Sanchez ◽  
Rudolf Weber ◽  
...  

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