scholarly journals Apparatus for Dynamical Texture Measurements by Neutron Diffraction Using a Position Sensitive- Detector

1983 ◽  
Vol 5 (4) ◽  
pp. 239-251 ◽  
Author(s):  
D. Juul Jensen ◽  
J. K. Kjems
Keyword(s):  
Neutron Diffraction ◽  
Position Sensitive Detector ◽  
Sensitive Detector ◽  
Neutron Spectrometer ◽  
Hot Air ◽  
New Apparatus ◽  
Position Sensitive ◽  
Set Up ◽  
Counting Statistics ◽  
Kinetics Of

A new apparatus for dynamical texture measurements using neutron diffraction has been developed. A variable wavelength neutron spectrometer has been modified to incorporate a linear position-sensitive detector. The sample is orientated by a fully automatic Euler goniometer, and it can be heated by a stream of hot air at rates up to 200℃/min. A quarter of a complete pole figure can be recorded in 14 minutes with an accuracy, determined by counting statistics, of 2–3%. The experimental set-up is described in the present paper and the performance, including sources of systematical errors, is discussed. Finally the viability of this apparatus is demonstrated by studies of the recrystallization kinetics of 95% cold rolled copper.

A position-sensitive detector for neutron diffraction topography

1988 ◽  
Vol 21 (1) ◽  
pp. 28-33 ◽  
Author(s):  
J. Baruchel ◽  
K. Kuroda ◽  
P. Liaud ◽  
A. Michalowicz ◽  
D. Sillou
Keyword(s):  
Neutron Diffraction ◽  
Thermal Neutron ◽  
Spatial Resolution ◽  
Detection Efficiency ◽  
Position Sensitive Detector ◽  
Sensitive Area ◽  
Sensitive Detector ◽  
Position Sensitive

The first test of a position-sensitive photomultiplier in a thermal neutron diffraction topography experiment is reported: a spatial resolution was obtained of ≃200 μm in FWHM over a sensitive area of size ≃8 × 8 mm (≃1600 pixels) and a detection efficiency of the order of 15% when using a 0.25 mm thick ZnS–LiF (NE 426) scintillator. The advantages of this detector, its foreseeable improvements, and the scientific problems it could help to solve are discussed.

Synthesizing and fitting linear position-sensitive detector step-scanned line profiles

1994 ◽  
Vol 27 (5) ◽  
pp. 673-681 ◽  
Author(s):  
R. W. Cheary ◽  
A. Coelho
Keyword(s):  
Incident Beam ◽  
Position Sensitive Detector ◽  
Physical Parameters ◽  
Sensitive Detector ◽  
X Ray ◽  
Powder Diffractometer ◽  
Experimental Step ◽  
Position Sensitive ◽  
Scan Data ◽  
Counting Statistics

An X-ray powder diffractometer has been modified by the addition of a narrow-bandpass germanium pre-monochromator and a linear position-sensitive detector (LPSD) with its centre set at the normal θ–2θ focusing condition. Diffraction data are recorded using a step-scan procedure in which the patterns recorded at each step are summed to form the final pattern over a wide angular range. In this way, diffraction patterns covering 120 2θ can be recorded 100 times more rapidly than with conventional receiving-slit diffractometers for the same level of counting statistics. In this paper, an analysis has been carried out of the contribution of the instrumental parameters to the shapes of the X-ray diffraction lines obtained with either a stationary or a step-scanned LPSD. This is done by calculating theoretical profiles for defocusing, parallax error, thermal-noise broadening and LPSD pixel size and convoluting them with the Cu Kα emission spectrum and aberration profiles associated with a standard focusing powder diffractometer. Theoretical profiles for fitting to experimental step-scan data are synthesized by summing convoluted profiles across the detector window. The validity of this procedure is tested by fitting to experimental step-scan data from well characterized reference specimens of MgO and Y3Al5O12 (YAG). The extra broadening associated with the inclusion of a LPSD is refined in terms of the depth of the detector, the angular window of the LPSD and the angle of divergence of the incident beam. Good fits have been obtained to the reference profiles and the physical parameters of the diffractometer determined in this way agree well with directly measured values.

scholarly journals Fast Texture Measurements Using a Position Sensitive Detector

1989 ◽  
Vol 10 (4) ◽  
pp. 361-373 ◽  
Author(s):  
Dorte Juul Jensen ◽  
Torben Leffers
Keyword(s):  
Neutron Diffraction ◽  
Time Resolution ◽  
Early Stage ◽  
Sensitive Detector ◽  
Measuring Time ◽  
Texture Measurement ◽  
Position Sensitive ◽  
Kinetic Investigations ◽  
Kinetics Of

A technique for fast texture determination by neutron diffraction is described. With the technique a complete texture analysis requires from 15 to 45 minutes measuring time and the kinetics of the development in single texture components can be studied with a time resolution of the order of seconds. It is shown how these two measuring principles can be used for in-situ kinetic investigations of recrystallization. Independent of speed, texture measurement by neutron diffraction has an advantage in improved statistics which is examplified by a series of measurements on the early stage of texture development in copper and brass.

scholarly journals Texture Analysis by Neutron Diffraction Using a Linear Position Sensitive Detector

1989 ◽  
Vol 10 (4) ◽  
pp. 375-387 ◽  
Author(s):  
G. Will ◽  
W. Schäfer ◽  
P. Merz
Keyword(s):  
Neutron Diffraction ◽  
Texture Analysis ◽  
Profile Analysis ◽  
Position Sensitive Detector ◽  
Sensitive Detector ◽  
X Ray ◽  
Position Sensitive ◽  
Hematite Ore ◽  
Position Sensitive Detectors ◽  
Low Symmetry

Neutron diffraction in connection with a position-sensitive detector is a most powerful technique in texture analysis comparable in time with conventional X-ray laboratory technique. Neutrons measure the global texture of the sample allowing volumes up to several cm3. By using position-sensitive detectors and applying the mathematical procedures of profile analysis multiphase and low symmetry materials can be investigated without serious difficulties. Neutron diffraction experiments operating in transmission record complete diffraction profiles; overlapping lines are unscrambled by profile analysis. Technical and physical specifications of the dedicated detector JULIOS, installed on the texture diffractometer of Bonn University, are given. A hematite ore has been studied by this technique and the results are given.

scholarly journals Neutron Diffraction Texture Analysis Using a 2θ-Position Sensitive Detector

1982 ◽  
Vol 5 (3) ◽  
pp. 153-170 ◽  
Author(s):  
H. J. Bunge ◽  
H. R. Wenk ◽  
J. Pannetier
Keyword(s):  
Neutron Diffraction ◽  
Independent Method ◽  
Position Sensitive Detector ◽  
Diffraction Spectrum ◽  
Sensitive Detector ◽  
Peak Separation ◽  
Large Lattice ◽  
Sample Position ◽  
Position Sensitive ◽  
Overlapping Peaks

A method for pole figure measurements in textured samples using neutron diffraction and a position sensitive detector is described. The position sensitive detector allows one to record the whole 2ϑ-spectrum of one sample position simultaneously, i.e. in reasonable time. The availability of the complete 2ϑ spectrum allows separation of overlapping peaks by a deconvolution process. A second independent method of peak separation is based on the crystallographic relations between peaks of various indices (hkl). The method allows extraction of the maximum possible information about the texture out of a polycrystal diffraction spectrum. It is thus especially suited to texture studies in materials having complex diffraction spectra with overlapping peaks, i.e. materials with low crystal symmetry and large lattice parameters as they are frequently encountered in geology.

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