Energy-Resolving Neutron Transmission Radiography at the ISIS Pulsed Spallation Source With a High-Resolution Neutron Counting Detector

2009 ◽  
Vol 56 (5) ◽  
pp. 2931-2937 ◽  
Author(s):  
Anton S. Tremsin ◽  
Jason B. McPhate ◽  
Winfried A. Kockelmann ◽  
John V. Vallerga ◽  
Oswald H. W. Siegmund ◽  
...  
Keyword(s):  
Spatial Resolution ◽  
Strain Analysis ◽  
Radiographic Image ◽  
Neutron Transmission ◽  
Neutron Sources ◽  
Spatially Correlated ◽  
Neutron Counting ◽  
Spallation Source ◽  
Pulsed Neutron ◽  
Energy Information

Neutron transmission radiography can be strongly enhanced by adding spectroscopic data spatially correlated with the attenuation coefficient. This can now be achieved at pulsed neutron sources, utilizing a neutron detector with high spatial and temporal resolution. The energy of transmitted neutrons can be recovered from their time-of-flight, simultaneously with the acquisition of the transmission radiographic image by a pixelated detector. From this, the positions of Bragg edges can be obtained for each pixel of the radiographic image. The combination of both spectroscopic and transmission information enables high spatial resolution studies to be carried out on material composition, phase transitions, texture variations, as well as strain analysis, as long as the resolution and statistics are favorable. This paper presents initial results from proof-of-principle experiments on energy-resolved neutron transmission radiography, using a neutron counting detector consisting of neutron-sensitive microchannel plates (MCPs) and a Medipix2 electronic readout. These experiments demonstrate that the position of Bragg edges are measurable with a few mAring resolution in each 55-mum pixel of the detector, corresponding to DeltaE/E~0.1%. However, the limited intensity of most current neutron sources requires a compromise between the energy resolution and the area over which it was integrated. Still, the latter limitation can be overcome by combining energy information for several neighboring pixels, while transmission radiography can still be done at the limit of the detector spatial resolution.

High-Resolution Strain Mapping Through Time-of-Flight Neutron Transmission Diffraction

2013 ◽  
Vol 772 ◽  
pp. 9-13 ◽  
Author(s):  
Anton S. Tremsin ◽  
Jason B. McPhate ◽  
John V. Vallerga ◽  
Oswald H.W. Siegmund ◽  
Winfried Kockelmann ◽  
...  
Keyword(s):  
High Resolution ◽  
Spatial Resolution ◽  
Time Of Flight ◽  
Compact Tension ◽  
Strain Mapping ◽  
Neutron Transmission ◽  
Neutron Counting ◽  
Transmission Measurements ◽  
Pulsed Neutron ◽  
Pulsed Neutron Source

The spatial resolution of time of flight neutron transmission diffraction was recently improved by the extension of photon/electron counting technology to imaging of thermal and cold neutrons. The development of novel neutron sensitive microchannel plates enables neutron counting with spatial resolution of ~55 um and time-of-flight accuracy of ~1 us, with efficiency as high as 70% for cold and ~40% for thermal neutrons. The combination of such a high resolution detector with a pulsed collimated neuron beam provides the opportunity to obtain a 2-dimensional map of neutron transmission spectra in one measurement. The results of our neuron transmission measurements demonstrate that maps of strains integrated along the beam propagation direction can be obtained with ~100 microstrain accuracy and spatial resolution of ~100 um providing there are sufficient neutron events collected. In this paper we describe the capabilities of the MCP neutron counting detectors and present the experimental results of 2-dimensional strain maps within austenitic steel compact tension (CT) crack samples measured at the ENGIN-X beamline of the ISIS pulsed neutron source.

Time-of-flight neutron transmission diffraction

2001 ◽  
Vol 34 (3) ◽  
pp. 289-297 ◽  
Author(s):  
J. R. Santisteban ◽  
L. Edwards ◽  
A. Steuwer ◽  
P. J. Withers
Keyword(s):  
Time Of Flight ◽  
Neutron Transmission ◽  
Lattice Strains ◽  
Nickel Powders ◽  
Transmission Geometry ◽  
Spallation Source ◽  
The Uk ◽  
Pulsed Neutron

The positions of Bragg edges in neutron transmission experiments can be defined with high accuracy using the time-of-flight (TOF) technique on pulsed neutron sources. A new dedicated transmission instrument has been developed at ISIS, the UK spallation source, which provides a precision of Δd/d≃ 10−5in the determination of interplanar distances. This is achieved by fitting a theoretical three-parameter expression to the normalized Bragg edges appearing in the TOF transmission spectra. The technique is demonstrated by experiments performed on iron, niobium and nickel powders. The applicability of using the instrument for the determination of lattice strains in materials has been investigated using a simplein situloading experiment. Details of the calibration process are presented and the dependence of the resolution and the experimental times required by the transmission geometry on the instrumental variables are studied. Finally, the requirements for a Rietveld-type refinement of transmission data and the advantages and limitations over traditional neutron diffraction peak analysis are discussed.

scholarly journals Short-Pulse Laser-Driven Moderated Neutron Source

2020 ◽  
Vol 231 ◽  
pp. 01008
Author(s):  
Sven C. Vogel ◽  
Juan C. Fernandez ◽  
D. Cort Gautier ◽  
Nikodem Mitura ◽  
Markus Roth ◽  
...  
Keyword(s):  
Short Pulse ◽  
Neutron Production ◽  
Particle Accelerators ◽  
Continue Development ◽  
Neutron Sources ◽  
Short Pulse Laser ◽  
Neutron Spallation Source ◽  
Spallation Source ◽  
Laser Sources ◽  
Pulsed Neutron

Neutron production with laser-driven neutron sources was demonstrated. We outline the basics of laser-driven neutron sources, highlight some fundamental advantages, and quantitatively compare the neutron production at the TRIDENT laser sources with the well-established LANSCE pulsed neutron spallation source. Ongoing efforts by our team to continue development of these sources, in particular the LANSCE-ina-box instrument, are described. The promise of ultra-intense lasers as drivers for brilliant, compact, and highly efficient particle accelerators portends driving next-generation neutron sources, potentially replacing in some cases much larger conventional accelerators.

scholarly journals Neutron capture data for unstable nuclei – Astrophysical quests and experimental challenges

2019 ◽  
Vol 23 ◽  
pp. 1
Author(s):  
F. Käppeler
Keyword(s):  
Cross Sections ◽  
Reaction Path ◽  
Chemical Elements ◽  
Neutron Sources ◽  
Unstable Nuclei ◽  
Quantitative Studies ◽  
Branching Points ◽  
Supernova Explosions ◽  
R Process ◽  
Pulsed Neutron

The abundances of the chemical elements heavier than iron can be attributed in about equal parts to the r and s processes, which are taking place in supernova explosions and during the He and C burning phases of stellar evolution, respectively. So far, quantitative studies of the r-process are out of reach, because it involves reactions on extremely short-lived neutron-rich nuclei. On the contrary, the situation for the s-process is far advanced, thanks to a comprehensive database of experimental (n,γ) cross sections for most isotopes along the reaction path from 12C to the Pb/Bi region. For the stable isotopes last gaps in the data are presently closed, but further studies are clearly needed to reach the required accuracy and to resolve remaining discrepancies. The quest for cross sections of unstable isotopes remains a persisting challenge though. In particular, nuclei which act as branching points are of prime interest, because they provide key information on the deep stellar interior. While the activation method is limited to a few exceptional branch-point nuclei, successful measurements via the time-of- flight technique are depending on intense pulsed neutron sources and elaborate methods for sample production. Current developments in Europe are providing promising perspectives in both areas.

scholarly journals High Spatial Resolution Neutron Transmission Imaging Using a Superconducting Two-Dimensional Detector

2021 ◽  
pp. 1-1
Author(s):  
Hiroaki Shishido ◽  
Kazuma Nishimura ◽  
The Dang Vu ◽  
Kazuya Aizawa ◽  
Kenji M Kojima ◽  
...  
Keyword(s):  
Spatial Resolution ◽  
High Spatial Resolution ◽  
Two Dimensional ◽  
Neutron Transmission ◽  
Transmission Imaging

PULSED NEUTRON SOURCES

1966 ◽  
pp. 329-381 ◽  
Author(s):  
R.H. STAHL ◽  
J.L. RUSSELL ◽  
G.R. HOPKINS
Keyword(s):  
Neutron Sources ◽  
Pulsed Neutron

scholarly journals 4D Bragg Edge Tomography of Directional Ice Templated Graphite Electrodes

2020 ◽  
Vol 6 (12) ◽  
pp. 136
Author(s):  
Ralf F. Ziesche ◽  
Anton S. Tremsin ◽  
Chun Huang ◽  
Chun Tan ◽  
Patrick S. Grant ◽  
...  
Keyword(s):  
Li Ion Battery ◽  
Graphite Electrodes ◽  
Neutron Spallation Source ◽  
Spallation Source ◽  
Li Ion ◽  
Tomography Method ◽  
First Time ◽  
Pulsed Neutron ◽  
Tomography Data ◽  
Insight Into

Bragg edge tomography was carried out on novel, ultra-thick, directional ice templated graphite electrodes for Li-ion battery cells to visualise the distribution of graphite and stable lithiation phases, namely LiC12 and LiC6. The four-dimensional Bragg edge, wavelength-resolved neutron tomography technique allowed the investigation of the crystallographic lithiation states and comparison with the electrode state of charge. The tomographic imaging technique provided insight into the crystallographic changes during de-/lithiation over the electrode thickness by mapping the attenuation curves and Bragg edge parameters with a spatial resolution of approximately 300 µm. This feasibility study was performed on the IMAT beamline at the ISIS pulsed neutron spallation source, UK, and was the first time the 4D Bragg edge tomography method was applied to Li-ion battery electrodes. The utility of the technique was further enhanced by correlation with corresponding X-ray tomography data obtained at the Diamond Light Source, UK.

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