Comparison of Stress Measurements by X-Rays with Three Different Detectors and a Strongly Fluorescing Specimen

1978 ◽  
Vol 22 ◽  
pp. 241-246 ◽  
Author(s):  
M. R. James ◽  
J. B. Cohen
Keyword(s):  
Solid State ◽  
Scintillation Detector ◽  
Position Sensitive Detector ◽  
X Rays ◽  
Sensitive Detector ◽  
Diffraction Profile ◽  
High Background ◽  
Solid State Detector ◽  
Position Sensitive ◽  
State Detector

Measurements on the heat affected zone of a weldment are presented using a gas filled position sensitive detector and a normal diffractometer equipped with a scintillation detector and a solid state detector. The sample, a surface ground titanium alloy, provided a difficult application for the X-ray technique from which a test of the real usefulness of the position sensitive detector could be made. The diffraction profile from the Ti alloy is very broad and the fluorescence produces a high background. The fluorescence is easily rejected using a solid state detector; however, the time of analysis is very long. With the position sensitive detector, the combination of increased energy discrimination over the scintillation detector and the simultaneous measurement of many data points over the broad peak enabled the measurements to be made for the same accuracy in much shorter times than for either the solid state detector or the scintillation detector.

Flat-cone diffractometer utilizing a linear position-sensitive detector

1978 ◽  
Vol 11 (3) ◽  
pp. 173-178 ◽  
Author(s):  
E. Prince ◽  
A. Wlodawer ◽  
A. Santoro
Keyword(s):  
Data Collection ◽  
Position Sensitive Detector ◽  
X Rays ◽  
Sensitive Detector ◽  
Diffraction Geometry ◽  
Data Rates ◽  
Common Plane ◽  
Mathematical Formulas ◽  
Position Sensitive ◽  
Position Sensitive Detectors

The recent development of linear position-sensitive detectors for neutrons and X-rays leads to the possibility of large improvements in the efficiency of data collection in single-crystal diffractometers. In order to take advantage of the properties of a linear position-sensitive detector it is desirable to use a diffraction geometry which causes the diffracted beams from many different reflecting planes to lie in a common plane. A design for a diffractometer utilizing the flat-cone geometry is described, and the relevant mathematical formulas are summarized. An instrument using this design has been constructed as a modification to an existing four-circle diffractometer and is now operating. Practical details of its construction, of the collection and handling of data, and of data rates are discussed.

A New Position Sensitive Detector for X-Ray Diffractometry

1992 ◽  
Vol 36 ◽  
pp. 617-622
Author(s):  
J. L. Radtke ◽  
D. W. Beard
Keyword(s):  
Position Sensitive Detector ◽  
Data Sets ◽  
X Rays ◽  
Sensitive Detector ◽  
Detector Performance ◽  
X Ray ◽  
Time Quantum ◽  
Position Sensitive ◽  
Diffraction Patterns ◽  
The Impact

AbstractPosition sensitive detectors provide efficient X-ray detection over large solid angles; this capability has revolutionized X-ray diffractometry by reducing data collection time. This paper describes testing of a new single-axis position sensitive detector designed to locate 0.6-2 Angstrom X-rays. Dead time, quantum efficiency, energy resolution, and spatial resolution were measured. Standard powder diffraction patterns were observed with the detector, and data sets are presented. The impact of detector performance parameters on diffraction experiments is discussed.

Crystal structure determination of lithium diborate hydrate, LiB2O3(OH).H2O, from X-ray powder diffraction data collected with a curved position-sensitive detector

1992 ◽  
Vol 25 (5) ◽  
pp. 617-623 ◽  
Author(s):  
D. Louër ◽  
M. Louër ◽  
M. Touboul
Keyword(s):  
Crystal Structure ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Structural Model ◽  
Rietveld Method ◽  
Position Sensitive Detector ◽  
X Rays ◽  
Sensitive Detector ◽  
Powder Diffraction Data ◽  
Position Sensitive

The crystal structure of lithium diborate hydrate, LiB2O3(OH).H2O, has been solved ab initio and refined by the Rietveld method from powder diffraction data collected with a curved position-sensitive detector (INEL CPS120) using Debye–Scherrer diffraction geometry with monochromatic X-rays. In the first stage the indexing of the powder pattern was performed by the successive dichotomy method from data collected with a diffractometer using Bragg–Brentano geometry. The lattice parameters are a = 9.7984 (10), b = 8.2759 (7) and c = 9.6138 (8) Å and the space group is Pnna. The structural model was obtained from direct methods and two difference Fourier maps. The Rietveld refinement converged to final crystal structure and profile indicators RF = 0.05, RB = 0.05, Rp = 0.03 and Rwp = 0.04. The structure consists of BO4 tetrahedra (T) and BO2(OH) triangles (Δ) sharing corners in order to form infinite chains along [010], with the shorthand notation 3:∞1(Δ + 2T). The particular linkage of the B3O3 rings leads to a new diborate anion {[B2O3(OH)] n− n }, in which two tetrahedral B atoms have an occupation factor of 0.5. Li atoms, tetrahedrally surrounded by four O atoms, three belonging to separate chains and one to a water molecule maintain the cohesion of the structure.

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