An Area-Imaging Proportional Counter for X-Ray Diffraction

1980 ◽  
Vol 24 ◽  
pp. 161-166 ◽  
Author(s):  
C. Richard Desper ◽  
Ronald Burns
Keyword(s):  
Data Acquisition ◽  
Proportional Counter ◽  
Orientation Angle ◽  
Polymeric Materials ◽  
Bragg Angle ◽  
Acquisition Time ◽  
Time Interval ◽  
X Ray Diffraction ◽  
Oriented Polymers ◽  
X Ray

Slow data acquisition rates have, in the past, limited the use of X-ray diffraction for characterization of polymeric materials. Photon counting techniques yield quantitative data in digital form for computer analysis. However, a great deal of data acquisition time is required when data is taken sequentially; i.e., when each intensity determination (at a particular goniometer setting) requires a separate time interval, during which intensity at other angle values is ignored. The problem is particularly acute for oriented polymers since two or more diffraction angles are involved: The Bragg angle along with at least one orientation angle. For this reason, an area-imaging (two-dimensional) proportional counter has been developed for use with a four-circle X-ray diffraction system. Although basically a single-crystal unit, this goniometer has been used in this laboratory and others for studies of oriented polymers. The receiving pinhole collimator and aperture have been removed, and the area-imaging counter has been mounted on the detector arm track. The original receiving aperture is still used for alignment, and the area detector Is positioned with its center at the receiving aperture center position.

Full-field X-ray diffraction microscopy using polymeric compound refractive lenses

2014 ◽  
Vol 47 (6) ◽  
pp. 1882-1888 ◽  
Author(s):  
J. Hilhorst ◽  
F. Marschall ◽  
T. N. Tran Thi ◽  
A. Last ◽  
T. U. Schülli
Keyword(s):  
Imaging Techniques ◽  
Light And Electron Microscopy ◽  
Added Value ◽  
Acquisition Time ◽  
Imaging Method ◽  
X Ray Diffraction ◽  
Polymeric Compound ◽  
Full Field ◽  
X Ray ◽  
Diffraction Imaging

Diffraction imaging is the science of imaging samples under diffraction conditions. Diffraction imaging techniques are well established in visible light and electron microscopy, and have also been widely employed in X-ray science in the form of X-ray topography. Over the past two decades, interest in X-ray diffraction imaging has taken flight and resulted in a wide variety of methods. This article discusses a new full-field imaging method, which uses polymer compound refractive lenses as a microscope objective to capture a diffracted X-ray beam coming from a large illuminated area on a sample. This produces an image of the diffracting parts of the sample on a camera. It is shown that this technique has added value in the field, owing to its high imaging speed, while being competitive in resolution and level of detail of obtained information. Using a model sample, it is shown that lattice tilts and strain in single crystals can be resolved simultaneously down to 10−3° and Δa/a= 10−5, respectively, with submicrometre resolution over an area of 100 × 100 µm and a total image acquisition time of less than 60 s.

Comparison between Rice Husk Ash and Commercial Silica as Filler in Polymeric Composites

2016 ◽  
Vol 869 ◽  
pp. 209-214 ◽  
Author(s):  
Iara Janaína Fernandes ◽  
Daiane Calheiro ◽  
Emanuele Caroline Araújo dos Santos ◽  
Roxane Oliveira ◽  
Tatiana Louise Avila de Campos Rocha ◽  
...  
Keyword(s):  
Rice Husk ◽  
Rice Husk Ash ◽  
Polymeric Materials ◽  
Fluidized Bed Reactor ◽  
Specific Weight ◽  
High Energy ◽  
Loss On Ignition ◽  
X Ray Diffraction ◽  
X Ray ◽  
Different Sources

The use of rice husk ash (RHA) as filler in polymeric materials has been studied in different polymers. Research reported that RHA may successfully replace silica. The silica production process using ore demands high energy input and produces considerable amounts of waste. Therefore, the replacement of silica by RHA may be economically and environmentally advantageous, reducing environmental impact and adding value to a waste material. In this context, this study characterizes and compares RHA of different sources (moving grate and fluidized bed reactor) with commercially available silicas to assess performance as filler in polymeric materials. Samples were characterized by X-ray fluorescence, loss on ignition, X-ray diffraction, grain size, specific surface area, specific weight, and scanning electron microscopy. The results show that RHA may be used as a filler in several polymeric materials.

In situ time-resolved X-ray diffraction of tobermorite formation process under hydrothermal condition: Influence of reactive al compound

2011 ◽  
Vol 26 (2) ◽  
pp. 134-137 ◽  
Author(s):  
K. Matsui ◽  
A. Ogawa ◽  
J. Kikuma ◽  
M. Tsunashima ◽  
T. Ishikawa ◽  
...  
Keyword(s):  
Hydrothermal Reaction ◽  
High Energy ◽  
Saturated Steam ◽  
Array Detector ◽  
Time Interval ◽  
X Rays ◽  
X Ray Diffraction ◽  
Formation Reaction ◽  
X Ray

Hydrothermal formation reaction of tobermorite in the autoclaved aerated concrete (AAC) process has been investigated by in situ X-ray diffraction. High-energy X-rays from a synchrotron radiation source in combination with a newly developed autoclave cell and a photon-counting pixel array detector were used. XRD measurements were conducted in a temperature range 100–190°C throughout 12 h of reaction time with a time interval of 4.25 min under a saturated steam pressure. To clarify the tobermorite formation mechanism in the AAC process, the effect of Al addition on the tobermorite formation reaction was studied. As intermediate phases, non-crystalline calcium silicate hydrate (C-S-H), hydroxylellestadite (HE), and katoite (KA) were clearly observed. Consequently, it was confirmed that there were two reaction pathways via C-S-H and KA in the tobermorite formation reaction of Al containing system. In addition, detailed information on the structural changes during the hydrothermal reaction was obtained.

X-ray Diffraction Measurements via a UNIX+ Based System

1984 ◽  
Vol 28 ◽  
pp. 241-247
Author(s):  
D. S. Dunn ◽  
T. F. Marinis
Keyword(s):  
Operating System ◽  
Data Acquisition ◽  
X Ray Diffraction ◽  
X Ray ◽  
Software Interface ◽  
System A ◽  
Unix Operating System ◽  
Processing And Storage ◽  
Data Acquisition Program ◽  
And Storage

We have automated a Seeman-Bohlin Guinier x-ray diffractometer by interfacing it to a minimally configured PDP 11/23 computer. The programs that run on the microcomputer to control the operation of the diffractometer are stored on a mainframe host running the UNIX+ operating system. A software interface allows a particular data acquisition program to be downloaded from the UNIX host and executed on the satellite processor. This same interface allows the collected data to be periodically off-loaded to the host for processing and storage.

scholarly journals Estimating the structure factors in X-ray diffraction

2018 ◽  
Vol 74 (5) ◽  
pp. 481-498 ◽  
Author(s):  
Paul F. Fewster
Keyword(s):  
Diffraction Theory ◽  
Bragg Angle ◽  
Enhancement Effect ◽  
Diffraction Effect ◽  
X Ray Diffraction ◽  
Acta Cryst ◽  
X Ray ◽  
Background Removal ◽  
Structure Factors ◽  
Path Lengths

This article takes the concepts of the `new diffraction theory' [Fewster (2014). Acta Cryst. A70, 257–282] and examines the implications for the interpretation of experimental results and the estimation of structure factors. Further experimental evidence is included to justify the conclusions in the theory, showing that the residual intensity at twice the Bragg angle is a diffraction effect and not associated with the crystal shape. This `enhancement' effect is independent of whether kinematical or dynamical theories are applied and can lead to a clearer understanding of how the dynamical effects are suppressed in imperfect crystals. By applying the idea that the higher-order peaks are due to path lengths of nλ, it is shown that `systematically absent' reflections in the conventional theory may not be absent. Because this new theory considers the intensity to be more distributed, it suggests that the entire structure factor can be difficult to capture by experiment. This article suggests some routes to achieve a good approximation of the structure factors for typical methods of data collection. Any measurement of intensity with background removal will exclude some of the distributed intensity, again leading to an underestimate of the structure factors, and therefore the missing intensity needs to be estimated.

Sign in / Sign up

Export Citation Format

Share Document