A new method for texture measurements using a general area detector diffraction system

2003 ◽  
Vol 18 (2) ◽  
pp. 99-102 ◽  
Author(s):  
Kurt Helming ◽  
Mike Lyubchenko ◽  
Bob He ◽  
Uwe Preckwinkel
Keyword(s):  
Data Collection ◽  
Data Quality ◽  
Pole Figure ◽  
New Method ◽  
General Area ◽  
X Ray ◽  
Area Detector ◽  
New Methods ◽  
Analysis Process ◽  
Pole Figure Data

Advances in X-ray texture solutions require new methods and descriptions for the texture analysis process, e.g., when using general area detector diffraction systems. A new method is presented that defines a general pole figure resolution and provides the possibility to optimize strategies for efficient pole figure data collection. Application of the new method improves resolution and (!) speed. New software enables simultaneous monitoring of pole and detector space. This allows a fundamentally better understanding of the collected information, e.g., in situations where peaks overlap or high backgrounds compromise data quality.

Elaboration on the hexagonal grid and spiral trace schemes for pole figure data collection

2008 ◽  
Vol 23 (2) ◽  
pp. 87-91 ◽  
Author(s):  
Anthony C. Rizzie ◽  
Thomas R. Watkins ◽  
E. Andrew Payzant
Keyword(s):  
Data Collection ◽  
Pole Figure ◽  
Aluminum Foil ◽  
Hexagonal Grid ◽  
Equal Area ◽  
X Ray ◽  
Pole Figures ◽  
Area Sampling ◽  
Data Points ◽  
Pole Figure Data

A practical description of the mathematics required to implement the hexagonal grid and spiral trace pole figure data collection schemes is presented. Applying the concepts of stereographic and equal area projections with geometry, spreadsheets were created to calculate the angular settings of the goniometer. Using the generated settings, the hexagonal grid and spiral trace schemes were programmed into the existing X-ray software and employed to collect data for a sample of aluminum foil. The resulting (111) pole figures were similar to those collected with the conventional 5°χ×5°ϕ grid. The hexagonal grid has been shown by others to reduce the number of data points and time needed to complete a pole figure, while providing equal area sampling. Although not optimized, the spiral method was also investigated as another alternative to the 5°χ×5°ϕ grid.

Use of a Two-Dimensional, Position Sensitive Detector for Collecting Pole Figures

1992 ◽  
Vol 36 ◽  
pp. 641-647 ◽  
Author(s):  
Kingsley L. Smith ◽  
Richard B. Ortega
Keyword(s):  
Data Collection ◽  
Pole Figure ◽  
Computer Control ◽  
Two Dimensional ◽  
Sensitive Detector ◽  
Area Detector ◽  
Pole Figures ◽  
Position Sensitive ◽  
Pole Figure Data ◽  
Collection Time

Conventional pole figure instruments consist of a scintillation detector mounted on a 4-circle goniometer operating under computer control. A few instruments make use of a linear PSD detector, which allows collecting data for multiple pole figures sinmltaneously. A PSD does not reduce the required data collection time for the primary pole figure; however, it does save time by eliminating the need to recollect multiple pole figure data. By using a 2D “area” detector, one can simultaneously collect multiple pole figures and reduce the data collection time for the primary pole figure, such an area detector pole figure processing package, GADDS v2, was developed at Siemens and will be discussed.

scholarly journals Automated harvesting and processing of protein crystals through laser photoablation

2016 ◽  
Vol 72 (4) ◽  
pp. 454-466 ◽  
Author(s):  
Ulrich Zander ◽  
Guillaume Hoffmann ◽  
Irina Cornaciu ◽  
Jean-Pierre Marquette ◽  
Gergely Papp ◽  
...  
Keyword(s):  
Data Collection ◽  
Macromolecular Crystallography ◽  
X Ray Diffraction ◽  
X Ray ◽  
New Methods ◽  
Repeated Sample ◽  
Sample Recovery ◽  
Through Diffusion ◽  
X Ray Background ◽  
Low X

Currently, macromolecular crystallography projects often require the use of highly automated facilities for crystallization and X-ray data collection. However, crystal harvesting and processing largely depend on manual operations. Here, a series of new methods are presented based on the use of a low X-ray-background film as a crystallization support and a photoablation laser that enable the automation of major operations required for the preparation of crystals for X-ray diffraction experiments. In this approach, the controlled removal of the mother liquor before crystal mounting simplifies the cryocooling process, in many cases eliminating the use of cryoprotectant agents, while crystal-soaking experiments are performed through diffusion, precluding the need for repeated sample-recovery and transfer operations. Moreover, the high-precision laser enables new mounting strategies that are not accessible through other methods. This approach bridges an important gap in automation and can contribute to expanding the capabilities of modern macromolecular crystallography facilities.

scholarly journals Development of a shutterless continuous rotation method using an X-ray CMOS detector for protein crystallography

2009 ◽  
Vol 42 (6) ◽  
pp. 1165-1175 ◽  
Author(s):  
Kazuya Hasegawa ◽  
Kunio Hirata ◽  
Tetsuya Shimizu ◽  
Nobutaka Shimizu ◽  
Takaaki Hikima ◽  
...  
Keyword(s):  
Data Collection ◽  
Dynamic Range ◽  
Protein Structures ◽  
Protein Crystallography ◽  
New Method ◽  
Oxide Semiconductor ◽  
X Ray ◽  
Rotation Method ◽  
Continuous Rotation ◽  
Wide Range

A new shutterless continuous rotation method using an X-ray complementary metal-oxide semiconductor (CMOS) detector has been developed for high-speed, precise data collection in protein crystallography. The principle of operation and the basic performance of the X-ray CMOS detector (Hamamatsu Photonics KK C10158DK) have been shown to be appropriate to the shutterless continuous rotation method. The data quality of the continuous rotation method is comparable to that of the conventional oscillation method using a CCD detector and, furthermore, the combination with fine φ slicing improves the data accuracy without increasing the data-collection time. The new method is more sensitive to diffraction intensity because of the narrow dynamic range of the CMOS detector. However, the strong diffraction spots were found to be precisely measured by recording them on successive multiple images by selecting an adequate rotation step. The new method has been used to successfully determine three protein structures by multi- and single-wavelength anomalous diffraction phasing and has thereby been proved applicable in protein crystallography. The apparatus and method may become a powerful tool at synchrotron protein crystallography beamlines with important potential across a wide range of X-ray wavelengths.

scholarly journals A Method for the Generation of Various Ghost Correction Algorithms—the Example of the Positivity Method and the Exponential Method

1991 ◽  
Vol 13 (4) ◽  
pp. 199-212 ◽  
Author(s):  
P. Van Houtte
Keyword(s):  
Pole Figure ◽  
Taylor Series ◽  
The Other ◽  
New Method ◽  
Series Expansions ◽  
Theoretical Scheme ◽  
Taylor Series Expansions ◽  
Exponential Method ◽  
Pole Figure Data

A theoretical strategy is presented that can derive the algorithms of several existing ghost correction methods. The examples of the positivity method and the “GHOST” method are elaborated. A new method is derived as well: the “exponential” method. It can successfully replace the quadratic method as a method that yields an exactly non-negative complete C.O.D.F. from pole figure data. The theoretical scheme that can generate all these algorithms makes use of the fact, that several parameter sets can be defined in order to describe a C.O.D.F. The parameters of one set are then functions of those of the other. The algorithms are derived from Taylor series expansions of these functions.

scholarly journals The crystalline sponge method updated

IUCrJ ◽  
2016 ◽  
Vol 3 (2) ◽  
pp. 139-151 ◽  
Author(s):  
Manabu Hoshino ◽  
Anupam Khutia ◽  
Hongzhu Xing ◽  
Yasuhide Inokuma ◽  
Makoto Fujita
Keyword(s):  
Data Collection ◽  
Data Quality ◽  
Site Occupancy ◽  
Porous Metal ◽  
Crystallographic Analysis ◽  
Chemical Information ◽  
Benchmark Test ◽  
X Ray ◽  
Chemical Crystallography ◽  
High Site

Crystalline sponges are porous metal complexes that can absorb and orient common organic molecules in their pores and make them observable by conventional X-ray structure analysis (crystalline sponge method). In this study, all of the steps in the crystalline sponge method, including sponge crystal preparation, pore–solvent exchange, guest soaking, data collection and crystallographic analysis, are carefully examined and thoroughly optimized to provide reliable and meaningful chemical information as chemical crystallography. Major improvements in the method have been made in the guest-soaking and data-collection steps. In the soaking step, obtaining a high site occupancy of the guest is particularly important, and dominant parameters for guest soaking (e.g.temperature, time, concentration, solvents) therefore have to be optimized for every sample compound. When standard conditions do not work, a high-throughput method is useful for efficiently optimizing the soaking conditions. The X-ray experiments are also carefully re-examined. Significant improvement of the guest data quality is achieved by complete data collection at high angle regions. The appropriate disorder treatment of the most flexible ZnI2portions of the host framework and refinement of the solvents filling the remaining void are also particularly important for obtaining better data quality. A benchmark test for the crystalline sponge method toward an achiral molecule is proposed with a guaiazulene guest, in which the guest structure (with ∼ 100% site occupancy) is refined without applying any restraints or constraints. The obtained data quality withRint= 0.0279 andR1= 0.0379 is comparable with that of current conventional crystallographic analysis for small molecules. Another benchmark test for this method toward a chiral molecule is also proposed with a santonin guest. The crystallographic data obtained [Rint= 0.0421,R1= 0.0312, Flack (Parsons) = −0.0071 (11)] represents the potential ability of this method for reliable absolute structure determination.

Protein and virus X-ray data collection with a Xentronics area detector

1984 ◽  
Vol 40 (a1) ◽  
pp. C404-C404
Author(s):  
R. M. Durbin ◽  
R. Burns ◽  
J. Moulai ◽  
P. Metcalf ◽  
S. C. Harrison ◽  
...  
Keyword(s):  
Data Collection ◽  
X Ray ◽  
Area Detector

scholarly journals Area Detector Systems: Setting Higher Standards for Data Quality

2014 ◽  
Vol 70 (a1) ◽  
pp. C1729-C1729
Author(s):  
Lee Daniels ◽  
Mathias Meyer
Keyword(s):  
Data Collection ◽  
Data Quality ◽  
Data Reduction ◽  
Real Life ◽  
Experimental Procedure ◽  
Area Detector ◽  
Additional Challenge ◽  
Major Factors ◽  
Data Collection Procedure

At least four major factors affect single-crystal diffraction data quality: 1) Hardware (source, goniometer and detector), 2) the sample, 3) the data collection procedure and strategy, and 4) the integration and data reduction software. Three of these factors can be carefully designed by the instrument manufacturer, and the other (the sample) can be chosen to optimize interaction with the instrument. We can define important hardware factors to allow quantification, such as absolute detectivity, overhead, readout speed, minimizing dead time and diffractometer access. Advances in area detector technology (including the new S2 generation of area detectors) and data collection approaches will be presented. The experimental procedure includes the choice of wavelength and the geometric strategy. Details of the detector operation (gain, bin-mode) can be optimized to fit the experiment. Agilent's latest CrysAlisPro software implements the 4th generation of strategy software and includes new on-the-fly detector optimization to provide significant gains in data quality. Integration software must be flexible in order to extract consistently good intensities from excellent samples and also from those that suffer from real-life flaws. Twinned samples represent an additional challenge. Agilent's new data reduction approach for twins significantly improves the data quality of both small molecule and protein twins.

Preparation of Lead Iodide as Input Material for X-Ray Detectors

2005 ◽  
Vol 480-481 ◽  
pp. 477-482 ◽  
Author(s):  
M. Matuchová ◽  
Olga Prochazková ◽  
K. Zdanský ◽  
J. Zavadil ◽  
J. Maixner
Keyword(s):  
Direct Synthesis ◽  
New Method ◽  
Lead Iodide ◽  
X Ray ◽  
New Methods ◽  
Input Material ◽  
Zone Purification

The aim of this work is to study the new method of direct synthesis of lead and iodine as the input material of PbI2. This method has not been studied for this material till now, and seems to be one of the new methods for preparation of the input material. The photoluminescence measurement and measurement of resistivity has been done and compared with the measurements done by precipitation and zone purification.

Using An Area Detector to Determine the Orientation Distribution Function

1994 ◽  
Vol 38 ◽  
pp. 511-516
Author(s):  
B. A. Squires ◽  
K. L. Smith
Keyword(s):  
Distribution Function ◽  
Data Collection ◽  
Pole Figure ◽  
Orientation Distribution ◽  
Polymer Fibers ◽  
Additional Time ◽  
Area Detector ◽  
Counting Statistics ◽  
Data Collection Procedure ◽  
Collection Time

AbstractWith the increased use of composite materials, it has become increasingly important to perform analysis that quantifies the amount of crystal lographic orientation. In polymers fibers and films the orientation is used to predict the physical properties, such as strength. To determine the orientation it is first necessary to collect a pole figure on a specific reflection. With the conventional powder diffiactometer equipped with an Eulerian cradle, the data collection procedure often lakes a few hours. Additional time is involved for separate background measurements, which are collected at 2θ positions away from the peak. Also, the intensity from these samples is usually weak, requiring increased data collection time to improve counting statistics.Using an area detector decreases the data collection time significantly, because the background experiments are performed simultaneously. We can collect the entire pole figure on both polymer fibers and films in less than one hour using a series of “frames.” The pole figure is determined by integrating over 2θ regions in each frame. For fibers the rules developed by Stein are used to calculate the Hermans orientation factors. For films, the rules are generalized to make them more suitable for biaxial orientation, and the White-Spniieli biaxial orientation factors are reported.

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