Optimization of an Experimental Setup for Void Fraction Determination by the X-Ray Attenuation Technique

Author(s):  
Th. Fournier ◽  
Ch. Jeandey
2018 ◽  
Vol 29 (12) ◽  
pp. 125303 ◽  
Author(s):  
Amitosh Dash ◽  
Saad Jahangir ◽  
Christian Poelma

2013 ◽  
Vol 28 (S2) ◽  
pp. S481-S490
Author(s):  
Oriol Vallcorba ◽  
Anna Crespi ◽  
Jordi Rius ◽  
Carles Miravitlles

The viability of the direct-space strategy TALP (Vallcorba et al., 2012b) to solve crystal structures of molecular compounds from laboratory powder diffraction data is shown. The procedure exploits the accurate metric refined from a ‘Bragg-Brentano’ powder pattern to extract later the intensity data from a second ‘texture-free’ powder pattern with the DAJUST software (Vallcorba et al., 2012a). The experimental setup for collecting this second pattern consists of a circularly collimated X-ray beam and a 2D detector. The sample is placed between two thin Mylar® foils, which reduces or even eliminates preferred orientation. With the combination of the DAJUST and TALP software a preliminary but rigorous structural study of organic compounds can be carried out at the laboratory level. In addition, the time-consuming filling of capillaries with diameters thinner than 0.3mm is avoided.


2019 ◽  
Vol 90 (8) ◽  
pp. 083905 ◽  
Author(s):  
Prakhyat Hejmady ◽  
Lucien C. Cleven ◽  
Lambèrt C. A. van Breemen ◽  
Patrick D. Anderson ◽  
Ruth Cardinaels

2002 ◽  
Vol 25 (8) ◽  
pp. 615-621 ◽  
Author(s):  
Abdullah Abbas Kendoush ◽  
Zareh Azat Sarkis

2014 ◽  
Vol 70 (a1) ◽  
pp. C1330-C1330
Author(s):  
Joerg Wiesmann ◽  
Andreas Kleine ◽  
Christopher Umland ◽  
André Beerlink ◽  
Juergen Graf ◽  
...  

Parasitic scattering caused by apertures is a well-known problem in X-ray analytics, which forces users and manufacturers to adapt their experimental setup to this unwanted phenomenon. Increased measurement times due to lower photon fluxes, a lower resolution caused by an enlarged beam stop, a larger beam defining pinhole-to-sample distance due to the integration of an antiscatter guard and generally a lower signal-to-noise ratio leads to a loss in data quality. In this presentation we will explain how the lately developed scatterless pinholes called SCATEX overcome the aforementioned problems. SCATEX pinholes are either made of Germanium or of Tantalum and momentarily have a minimum diameter of 30µm. Thus, these novel apertures are applicable to a wide range of different applications and X-ray energies. We will show measurements which were performed either at home-lab small angle X-ray scattering (SAXS) systems such as the NANOSTAR of Bruker AXS or at synchrotron beamlines. At the PTB four-crystal monochromator beamline at BESSY II data was collected for a comparison of conventional pinholes, scatterless Germanium slit systems and SCATEX pinholes. At the Nanofocus Endstation P03 beamline at PETRA III we compared the performance of our SCATEX apertures with conventional Tungsten slit systems under high flux density conditions.


2018 ◽  
Vol 74 (6) ◽  
pp. 673-680 ◽  
Author(s):  
V. G. Kohn

The article reports an accurate theory of X-ray coplanar multiple diffraction for an experimental setup that consists of a generic synchrotron radiation (SR) source, double-crystal monochromator (M) and slit (S). It is called for brevity the theory of X-ray coplanar multiple SRMS diffractometry. The theory takes into account the properties of synchrotron radiation as well as the features of diffraction of radiation in the monochromator crystals and the slit. It is shown that the angular and energy dependence (AED) of the sample reflectivity registered by a detector has the form of a convolution of the AED in the case of the monochromatic plane wave with the instrumental function which describes the angular and energy spectrum of radiation incident on the sample crystal. It is shown that such a scheme allows one to measure the rocking curves close to the case of the monochromatic incident plane wave, but only using the high-order reflections by monochromator crystals. The case of four-beam (220)(331)({\overline {11}}1) diffraction in Si is considered in detail.


Author(s):  
Kenichi Katono ◽  
Jun Nukaga ◽  
Takuji Nagayoshi ◽  
Kenichi Yasuda

We have been developing a void fraction distribution measurement technique using the three-dimensional (3D) time-averaged X-ray CT (computed tomography) system to understand two-phase flow behavior inside a fuel assembly for BWR (boiling water reactor) thermal hydraulic conditions of 7.2 MPa and 288 °C. Unlike CT images of a normal standstill object, we can obtain 3D CT images that are reconstructed from time-averaged X-ray projection data of the intermittent two-phase flow. We measured the 3D void fraction distribution in a vertical square (5 × 5) rod array that simulated a BWR fuel assembly in the air-water test. From the 3D time-averaged CT images, we confirmed that the void fraction at the center part of the channel box was higher than that near the channel box wall, and the local void fraction at the central region of a subchannel was higher than that at the gap region of the subchannel. A comparison of the volume-averaged void fractions evaluated by the developed X-ray CT system with those evaluated by a differential pressure transducer in a void fraction range from 0.05 to 0.40 showed satisfactory agreement within a difference of 0.03.


Author(s):  
Takao ISHIZUKA ◽  
Akira INOUE ◽  
Tatuo KUROSU ◽  
Toshimasa AOKI ◽  
Masanobu FUTAKUCHI ◽  
...  

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