Effect of gauge volume on strain measurement in rock materials using time-of-flight neutron diffraction

2018 ◽  
Vol 551 ◽  
pp. 283-286
Author(s):  
Jun Abe ◽  
Kotaro Sekine ◽  
Stefanus Harjo ◽  
Takuro Kawasaki ◽  
Kazuya Aizawa
Keyword(s):  
Neutron Diffraction ◽  
Strain Measurement ◽  
Time Of Flight ◽  
Rock Materials ◽  
Gauge Volume

Effect of Neutron Attenuation on Strain Measurement with Large Gauge Volume

2013 ◽  
Vol 772 ◽  
pp. 33-38 ◽  
Author(s):  
Hiroshi Suzuki ◽  
Jinya Katsuyama ◽  
Koichi Akita
Keyword(s):  
Neutron Diffraction ◽  
Strain Measurement ◽  
Normal Strain ◽  
Structural Components ◽  
Diffraction Intensity ◽  
Butt Weld ◽  
Attenuation Effect ◽  
Neutron Attenuation ◽  
Gauge Volume ◽  
Apparent Strain

When measuring residual strain distributions of thick structural components such as thick butt-welds using neutron diffraction, it is required to make a gauge volume larger as well as to shorten neutron path length in a material to obtain sufficient diffraction intensity. In this study, neutron attenuation effect on the strain measurement with a large gauge volume was discussed on the normal strain measurement of a thick butt-weld. Influences of neutron attenuation like an apparent strain change were observed, and it was more noticeable when the gauge volume becomes larger. Therefore, the neutron attenuation effect should be considered in the strain measurement with a large gauge volume, and the neutron absorption corrections certainly play an important role for improvement of reliabilities of strain measurement using neutron diffraction with a large gauge volume.

scholarly journals Through-Thickness Microstructure Characterization in a Centrifugally Cast Austenitic Stainless Steel Nuclear Reactor Primary Loop Pipe Using Time-of-Flight Neutron Diffraction

2021 ◽  
Vol 5 (2) ◽  
pp. 12
Author(s):  
Matthew M. Schmitt ◽  
Daniel J. Savage ◽  
James J. Wall ◽  
John D. Yeager ◽  
Chanho Lee ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Neutron Diffraction ◽  
Time Of Flight ◽  
Radial Distance ◽  
Ultrasonic Waves ◽  
Science Center ◽  
Los Alamos ◽  
Inspection Method ◽  
Centrifugally Cast

The US code of Federal Regulations mandates regular inspection of centrifugally cast austenitic stainless steel pipe, commonly used in primary cooling loops in light-water nuclear power plants. These pipes typically have a wall thickness of ~8 cm. Unfortunately, inspection using conventional ultrasonic techniques is not reliable as the microstructure strongly attenuates ultrasonic waves. Work is ongoing to simulate the behavior of acoustic waves in this microstructure and ultimately develop an acoustic inspection method for reactor inspections. In order to account for elastic anisotropy in the material, the texture in the steel was measured as a function of radial distance though the pipe wall. Experiments were conducted on two 10 × 12.7 × 80 mm radial sections of a cast pipe using neutron diffraction scans of 2 mm slices using the HIPPO time-of-flight neutron diffractometer at the Los Alamos Neutron Science Center (LANSCE, Los Alamos, NM, USA). Strong textures dominated by a small number of austenite grains with their (100) direction aligned in the radial direction of the pipe were observed. ODF analysis indicated that up to 70% of the probed volume was occupied by just three single-grain orientations, consistent with grain sizes of almost 1 cm. Texture and phase fraction of both ferrite and austenite phases were measured along the length of the samples. These results will inform the development of a more robust diagnostic tool for regular inspection of this material.

Analytical model for neutron diffraction peak shifts due to the surface effect

2013 ◽  
Vol 46 (3) ◽  
pp. 628-638 ◽  
Author(s):  
Jan Šaroun ◽  
Joana Rebelo Kornmeier ◽  
Michael Hofmann ◽  
Pavol Mikula ◽  
Miroslav Vrána
Keyword(s):  
Neutron Diffraction ◽  
Analytical Model ◽  
Surface Effect ◽  
Perfect Crystal ◽  
Optimum Configuration ◽  
Gauge Volume ◽  
Spurious Peak ◽  
Incomplete Filling ◽  
Broad Variety ◽  
Residual Strains

Residual strains measured by neutron diffraction near sample boundaries can be biased by the surface effect as a result of incomplete filling of the instrumental gauge volume. This effect is manifested as anomalous shifts of diffraction lines, which can be falsely interpreted as a lattice strain unless appropriate data corrections are made. A new analytical model for the surface effect has been developed, which covers a broad variety of instrumental arrangements, including flat mosaic and bent perfect crystal monochromators, narrow slits, and Soller and radial collimators. This model permits the spurious peak shifts to be predicted quantitatively, and also allows the optimum configuration parameters, such as curvature of a focusing monochromator, which lead to suppression of the surface effect, to be calculated. The model has been thoroughly validated by comparisons with Monte Carlo simulations and experiments on a stress-free calibration sample. Predictions of the model proved to be very accurate, often within the interval of experimental errors, which makes it suitable for use in data analysis.

Time-of-flight neutron diffraction of nanocrystalline powders of nonstoichiometric niobium carbide NbC0.77

2017 ◽  
Vol 59 (3) ◽  
pp. 607-612 ◽  
Author(s):  
A. S. Kurlov ◽  
A. I. Gusev ◽  
V. S. Kuznetsov ◽  
I. A. Bobrikov ◽  
A. M. Balagurov ◽  
...  
Keyword(s):  
Neutron Diffraction ◽  
Niobium Carbide ◽  
Time Of Flight ◽  
Nanocrystalline Powders

Dynamical diffraction peak splitting in time-of-flight neutron diffraction

2006 ◽  
Vol 89 (23) ◽  
pp. 233515
Author(s):  
E. Üstündag ◽  
R. A. Karnesky ◽  
M. R. Daymond ◽  
I. C. Noyan
Keyword(s):  
Neutron Diffraction ◽  
Time Of Flight ◽  
Diffraction Peak ◽  
Dynamical Diffraction ◽  
Peak Splitting

Imaging crystallographic phases using time-of-flight neutron diffraction

2006 ◽  
Vol 385-386 ◽  
pp. 1203-1205 ◽  
Author(s):  
Matthias Gutmann ◽  
Winfried Kockelmann ◽  
Laurent Chapon ◽  
Paolo G. Radaelli
Keyword(s):  
Neutron Diffraction ◽  
Time Of Flight

scholarly journals Time-of-Flight Three Dimensional Neutron Diffraction in Transmission Mode for Mapping Crystal Grain Structures

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Alberto Cereser ◽  
Markus Strobl ◽  
Stephen A. Hall ◽  
Axel Steuwer ◽  
Ryoji Kiyanagi ◽  
...  
Keyword(s):  
Neutron Diffraction ◽  
Three Dimensional ◽  
Time Of Flight ◽  
Transmission Mode ◽  
Grain Structures

Measuring strain and stress distributions along rebar embedded in concrete using time-of-flight neutron diffraction

2014 ◽  
Vol 25 (2) ◽  
pp. 025602 ◽  
Author(s):  
H Suzuki ◽  
K Kusunoki ◽  
Y Hatanaka ◽  
T Mukai ◽  
A Tasai ◽  
...  
Keyword(s):  
Neutron Diffraction ◽  
Time Of Flight ◽  
Stress Distributions
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