The Experts below are selected from a list of 114 Experts worldwide ranked by ideXlab platform
C. C. Tang - One of the best experts on this subject based on the ideXlab platform.
-
Low‐temperature Debye–Scherrer powder diffraction on Beamline I11 at Diamond
Journal of Applied Crystallography, 2013Co-Authors: Jonathan Potter, Julia E. Parker, A.r. Lennie, Stephen P. Thompson, C. C. TangAbstract:A bespoke capillary sample holder is described that attaches to the cold head of a commercially manufactured (PheniX) closed-cycle helium cryostat originally intended for flat-plate geometry. The new holder allows high-resolution synchrotron powder diffraction data to be collected from samples in Debye–Scherrer geometry over the temperature range 11–295 K. To demonstrate that high-quality powder data can be obtained using this new sample holder, structural refinement (Rietveld) and thermal expansion results measured from reference samples (Si and Al) are presented.
Toshihiko Sasaki - One of the best experts on this subject based on the ideXlab platform.
-
Improvement in X-ray stress measurement using Debye–Scherrer rings by in-plane averaging
Journal of Applied Crystallography, 2016Co-Authors: Toshiyuki Miyazaki, Yohei Fujimoto, Toshihiko SasakiAbstract:A technique to improve X-ray stress measurement using Debye–Scherrer rings is reported. In previous work, a Fourier-series-based generalization of the cosα method was proposed, which can measure the stress from a Debye–Scherrer ring. That technique and the cosα method have difficulties in determining the stress when the grain size of the specimen is relatively large and the Debye–Scherrer ring is grainy. To cope with this problem, in-plane averaging has been used to improve the cosα method when measuring coarse-grained specimens. In this study, Fourier series analysis is incorporated with in-plane averaging and it is explained how in-plane averaging improves the stress measurement. Furthermore, the validity of the new technique is demonstrated by measuring the stress of a carbon steel specimen.
-
Linearized analysis of X-ray stress measurement using the Debye–Scherrer ring
International Journal of Materials Research, 2015Co-Authors: Toshiyuki Miyazaki, Toshihiko SasakiAbstract:Abstract A linearized analysis of the Debye–Scherrer ring (D–S ring) is proposed in this paper. In our previous works, the authors reported on a technique to calculate stress from the Fourier serie...
-
X-ray stress measurement from an imperfect Debye–Scherrer ring
International Journal of Materials Research, 2015Co-Authors: Toshiyuki Miyazaki, Toshihiko SasakiAbstract:Abstract A technique to measure the stress from an imperfect Debye–Scherrer ring is reported. In a previous work, the authors reported a technique to calculate the stress from the Fourier series of a normal strain of a Debye–Scherrer ring and suggested that it is possible to calculate the stress from an imperfect Debye–Scherrer ring if the Fourier series is obtained. The present work presents a technique to calculate the Fourier series of an imperfect Debye–Scherrer ring. Industrially, this is important because the object of interest is often covered by other objects or engraved. The aim of this work is to develop a technique that extends the application range of the X-ray stress measurement.
-
X-ray stress measurement with two-dimensional detector based on Fourier analysis
International Journal of Materials Research, 2014Co-Authors: Toshiyuki Miyazaki, Toshihiko SasakiAbstract:Abstract A two-dimensional X-ray diffraction technique for stress measurement is reported. The proposed technique determines the stress from the Fourier series of a Debye–Scherrer ring. This technique does not require sample inclination to several different angles to determine the stress as the conventional sin2 ψ technique does. Although the cos α technique has the same advantage, the proposed technique can also determine stress from an imperfect Debye–Scherrer ring. To measure the effectiveness of the proposed technique, a four-point bending test was performed on a steel specimen to determine the Fourier series of Debye–Scherrer rings. The stresses determined from the Fourier series were consistent with those determined using the cos α technique. The proposed technique is expected to extend the application range of current X-ray stress measurement.
-
proposal of method to make pole figure using imaging plate
Transactions of the Japan Society of Mechanical Engineers. A, 1998Co-Authors: Tokimasa Goto, Toshihiko Sasaki, Yukio Hirose, Shinichi NagashimaAbstract:The state of texture in polycrystalline materials can be understood through a pole figure, which is measured by the X-ray diffraction technique. In this study, a method to measure the pole figure with imaging plate (IP) was proposed. IP as a two dimensional detector can measure the entire Debye-Scherrer ring, and pole density distribution of multi direction can be recorded on the Debye-Scherrer ring at the same time. Moreover, if two or more Debye-Scherrer rings are recorded on an IP, two or more pole figures can be obtained at one measurement. The measurement of the pole figure using IP has the possibility to become more efficient than the measurement by conventional method. In conventional method, X-ray device which equipped with Schulz's goniometer and a pulse-counter is used. The measurement device which adopted this method was made, and the pole figure of a textured rolled aluminum sheet was measured. Finally, the measurement accuracy of this method was proven by comparing pole figures which had been obtained by this method and a conventional method.
Jens Als-nielsen - One of the best experts on this subject based on the ideXlab platform.
-
The Debye-Scherrer camera at synchrotron sources: a revisit.
Journal of synchrotron radiation, 2012Co-Authors: Tine Straasø, Jacob Becker, Bo Brummerstedt Iversen, Jens Als-nielsenAbstract:In a powder diffraction pattern one measures the intensity of Miller-indexed Bragg peaks versus the wavevector transfer sinθ/λ. With increasing wavevector transfer the density of occurrence of Bragg peaks increases while their intensity decreases until they vanish into the background level. The lowest possible background level is that due to Compton scattering from the powder. A powder diffraction instrument has been designed and tested that yields this ideal low-background level, obtainable by having the space between sample and detector all in vacuum with the entrance window so far upstream that scattering from it is negligible. To minimize overlap of Bragg peaks the combination of fine collimation of synchrotron radiation, a thin cylindrical sample and a high-resolution imaging plate detector is taken advantage of.
V. N. Shalyapin - One of the best experts on this subject based on the ideXlab platform.
-
Multipurpose synchrotron spectrometer of the Kurchatov Institute: Part 3. Diffraction in Debye–Scherrer geometry
Physics of Particles and Nuclei Letters, 2017Co-Authors: Sergey I. Tyutyunnikov, A. N. Artemiev, A. D. Belyaev, Nikolay A. Artemiev, A. A. Demkiv, B. F. Kirillov, V. N. Shalyapin, M. V. Kovalchiuk, G. A. KnyazevAbstract:The performance of a multipurpose synchrotron spectrometer is diversified by installing additional equipment for the studies of diffraction in the Debye–Scherrer geometry. The design of X-ray optics and technical characteristics of the spectrometer are described. Diffraction patterns for polycrystals detected in both the forward and backward hemispheres are illustrated.
-
Debye-Scherrer diffraction in the backscattering geometry at the kurchatov synchrotron radiation source: Part 2. Equipment, pilot experiments, and data processing
Journal of Surface Investigation. X-ray Synchrotron and Neutron Techniques, 2014Co-Authors: A. N. Artemiev, A. D. Belyaev, Nikolay A. Artemiev, A. A. Demkiv, A. G. Maevsky, O. Yu. Gorobtsov, B. F. Kirillov, G. A. Knyazev, Sergey I. Tyutyunnikov, V. N. ShalyapinAbstract:Equipment is constructed, a technique is developed, and experimental results on Debye-Scherrer diffraction in the backscattering geometry are obtained. A special program for diffraction ring processing is developed. The prospects for use of this technique for materials science purposes are discussed.
-
Debye-Scherrer diffraction in the backscattering geometry at the Kurchatov Synchrotron Radiation source. Part 1. Characterization of the method
Journal of Surface Investigation. X-ray Synchrotron and Neutron Techniques, 2013Co-Authors: A. N. Artemiev, A. D. Belyaev, Nikolay A. Artemiev, A. A. Demkiv, A. G. Maevsky, O. Yu. Gorobtsov, B. F. Kirillov, Sergey I. Tyutyunnikov, V. N. ShalyapinAbstract:A technique for Debye-Scherrer diffraction in the backscattering geometry is developed at the Kurchatov Synchrotron Radiation source. It is shown that the sensitivity of the method to a relative change in the lattice constant is higher by two orders of magnitude than that in the forward-scattering geometry. The requirements for experimental apparatus are discussed.
Jonathan Potter - One of the best experts on this subject based on the ideXlab platform.
-
Low‐temperature Debye–Scherrer powder diffraction on Beamline I11 at Diamond
Journal of Applied Crystallography, 2013Co-Authors: Jonathan Potter, Julia E. Parker, A.r. Lennie, Stephen P. Thompson, C. C. TangAbstract:A bespoke capillary sample holder is described that attaches to the cold head of a commercially manufactured (PheniX) closed-cycle helium cryostat originally intended for flat-plate geometry. The new holder allows high-resolution synchrotron powder diffraction data to be collected from samples in Debye–Scherrer geometry over the temperature range 11–295 K. To demonstrate that high-quality powder data can be obtained using this new sample holder, structural refinement (Rietveld) and thermal expansion results measured from reference samples (Si and Al) are presented.
