Jean Bilheux

• PhD
• Software at Oak Ridge National Laboratory

Over the past decade, Oak Ridge National Laboratory developed neutron capabilities at both the High Flux Isotope Reactor and the Spallation Neutron Source. A broad scientific portfolio has flourished at both facilities such that a new facility named VENUS is currently under construction at the Spallation Neutron Source. With a large range of applic...

Located at the Spallation Neutron Source, VENUS is an instrument optimized for wavelength-dependent neutron imaging techniques, namely Bragg edge and resonance imaging, across a broad range of neutron energies (from meV to hundreds of eV). The VENUS construction project started in Fall 2018, establishing a conceptual design of the major components...

Attenuation-based neutron computed tomography (CT) has been used to non-destructively characterize the uncoated tristructural-isotropic (TRISO) nuclear fuel kernels in this work. Particularly, the effect of two different types of carbon blacks (Raven 3500 and Mogul L) on the internal gelation process of UO3-C kernels has been investigated. With 3D...

The pyRS (Python residual stress) analysis software was designed to address the data reduction and analysis needs of the High Intensity Diffractometer for Residual Stress Analysis (HIDRA) user community. pyRS implements frameworks for the calibration and reduction of measured 2D data into intensity versus scattering vector magnitude and subsequent...

Microstructures produced by Additive Manufacturing (AM) techniques determine many characteristics of components produced by this particular manufacturing technique. Residual stress and texture are among those characteristics, which need to be optimized to meet dimensional and strength requirements. Post-build heat treatments are necessary to relief...

The investigation of microstructure of crystalline materials is one of the possible and frequently used applications of energy-resolved neutron imaging. The position of Bragg edges is defined by sharp changes in neutron transmission and can thus be determined by the measurement of the transmission spectra as a function of neutron wavelength. The ac...

An interactive web-based tool has been developed at Oak Ridge National Laboratory (ORNL) to guide the end-user sample preparation for neutron imaging experiments. The tool is capable of estimating transmission through the sample using the cold neutron spectrum at the High Flux Isotope (HFIR) CG-1D imaging beamline. It can also predict the position...

Independently of the image modality (x-rays, neutrons, etc), image data analysis requires normalization, a preprocessing step. While the normalization can sometimes easily be generalized, the analysis is, in most cases, specific to an experiment and a sample. Although many tools (MATLAB, ImageJ, VG Studio…) offer a large collection of pre-programme...

As lithium-on (Li-ion) batteries increase in their prevalence and the range of applications expands, there is a need to understand and exploit the limits of electrochemical performance. Probing the internal processes in Li-ion batteries provides insights into the electrochemical characteristics of the cells as well as information necessary for rati...

The polarized neutron imaging technique provides a non-invasive method of characterizing localized magnetic fields inside superconductors. However, complete understanding of the magnetic field distribution has yet to be realized experimentally due to the complexity of the interaction between neutron polarization and magnetic field. In this article,...

Spontaneous imbibition (SI) is a capillary-driven flow process, in which a wetting fluid moves into a porous medium displacing an existing non-wetting fluid. This process likely contributes to the loss of fracking fluids during hydraulic fracturing operations. It has also been proposed as a method for an enhanced recovery of hydrocarbons from fract...

Hydrogen is an element of fundamental importance for energy but hard to quantify in bulk materials. Neutron radiography was used to map . in situ loss of elemental hydrogen from beech tree wood samples during pyrolysis. The samples consisted of three wood cylinders (finished dowel or cut branch) of approximately 1 cm in length. The samples were pyr...

Bragg-edge imaging, which is also known as neutron radiography, has recently emerged as a novel crystalline characterization technique. Modelling of this novel technique by incorporating various features of the underlying microstructure (including the crystallographic texture, the morphological texture, and the grain size) of the material remains a...

Three brass sestertius coins from the reign of Gordian III were imaged at the Oak Ridge National Laboratory’s neutron imaging beam, CG-1D, at the High Flux Isotope Reactor. Tomography results showed a gradual variation in neutron attenuation from one side of the coins to the other or toward the center of the coin. Linear neutron attenuation values...

Over the past decade, wavelength-dependent neutron radiography, also known as Bragg-edge imaging, has been employed as a non-destructive bulk characterization method due to its sensitivity to coherent elastic neutron scattering that is associated with crystalline structures. Several analysis approaches have been developed to quantitatively determin...

ImagingReso is an open-source Python library that simulates the neutron resonance signal for neutron imaging measurements. By defining the sample information such as density, thickness in the neutron path, and isotopic ratios of the elemental composition of the material, this package plots the expected resonance peaks for a selected neutron energy...

Neutron Resonance Imaging of Advanced Nuclear Fuel.

Li-Mg alloys are promising as positive electrodes (anodes) for Li-ion batteries due to the high Li storage capacity and the relatively lower volume change during the lithiation/delithiation process. They also present a unique opportunity to image the Li distribution through the electrode thickness at various delithiation states. In this work, spati...

Reflectivity measurements offer unique opportunities for the study of surfaces and interfaces, and specular reflectometry has become a standard tool in materials science to resolve structures normal to the surface of a thin film. Off-specular scattering, which probes lateral structures, is more difficult to analyse, because the Fourier space being...

Recent advances in neutron sources and detector technologies enable new contrast mechanisms to determine crystalline information for metal components.

The core code of the software Överlåtaren, as is presented in the article PO5077 ''Överlåtaren' a fast way to transfer and orthogonalize 2D offspecular reflectivity data' in the Journal of Applied Crystallography

Hydrogen content and distribution in Zircaloy-4 cladding samples with controlled hydrogen concentrations up to 1100ppm were studied using neutron radiography and computed tomography. Hydrogen charging was performed in a process tube that was heated to facilitate hydrogen absorption by the metal. A correlation between the hydrogen concentration in t...

The Oak Ridge National Laboratory Neutron Sciences Directorate has installed a neutron imaging beamline at the High Flux Isotope Reactor (HFIR) cold guide hall. CG-1D is one of the three instruments that make up the CG1 instrument suite. The beamline optics and detector have recently been upgraded to meet the needs of the neutron imaging community...

Image processing has become a mainstream capability with commercial software that allow the general public to perfom, for example, photograph enhancement such as noise reduction or deblurring. Scientific imaging data sets often require quantitative image analysis that can only be performed with careful algorithm development. Recently, a number of s...

One of the most difficult challenges in forensic research is to objectively determine the post-mortem interval (PMI). The accuracy of PMI is critical for determining the timeline of events surrounding a death. Most PMI techniques rely on gross morphological changes of cadavers that are highly sensitive to taphonomic factors. Recent studies have dem...

Mantid: A high performance framework for the reduction and analysis of muon spin resonance and neutron scattering data.

Mantid: A high performance framework for the reduction and analysis of muon spin resonance and neutron scattering data.

Mantid: A high performance framework for the reduction and analysis of muon spin resonance and neutron scattering data.

The Mantid framework is a software solution developed for the analysis and visualization of neutron scattering and muon spin measurements. The framework is jointly developed by software engineers and scientists at the ISIS Neutron and Muon Facility and the Oak Ridge National Laboratory. The objectives, functionality and novel design aspects of Mant...

The advent of the fast-valve device, described previously, permits measurement of molecular-flow times of chemically active or inactive gaseous species through radioactive ion beam (RIB) target–ion–source systems, independent of size, geometry and materials of construction. Thus, decay losses of short-half-life RIBs can be determined for a given ta...

The Oak Ridge National Laboratory Neutron Sciences Directorate (NScD) has recently installed a neutron imaging beamline at the High Flux Isotope Reactor (HFIR) cold guide hall. The CG-1D beamline supports a broad range of user research spanning from engineering to material research, energy storage, additive manufacturing, vehicle technologies, arch...

Imaging modalities for cancer detection include X-ray, computed tomography, magnetic resonance imaging, ultrasound, positron emission tomography, and optical imaging. Each imaging technology has advantages and disadvantages with limitations either in spatial resolution or sensitivity for cancer detection. Hydrogen nuclei scatter cold neutrons stron...

Exhaust gas recirculation (EGR) cooler fouling has become a significant issue for compliance with NOx emissions standards. Exhaust gas laden with particulate matter flows through the EGR cooler which causes deposits to form through thermophoresis and condensation. The low thermal conductivity of the resulting deposit reduces the effectiveness of th...

Neutron imaging is a nondestructive application capable of producing two- and three-dimensional maps of archaeological objects’ external and internal structure, properties, and composition. This report presents the recent development of neutron imaging data collection and processing methods at Oak Ridge National Laboratory (ORNL), which have been a...

This article presents the initial results of 2-D and 3-D neutron imaging of bronze artifacts using the CG-1D prototype beamline at the High Flux Isotope Reactor (HFIR) located at the Oak Ridge National Laboratory (ORNL). Neutron imaging is a non-destructive technique capable of producing unprecedented three-dimensional information on archaeomateria...

Conceptually, modern medical imaging can be traced back to the late 1960's and into the early 1970's with the advent of computed tomography . This pioneering work was done by 1979 Nobel Prize winners Godfrey Hounsfield and Allan McLeod Cormack which evolved into the first prototype Computed Tomography (CT) scanner in 1971 and became commercially av...

In a busy world, continuing with the status-quo, to do things the way we are already familiar, often seems to be the most efficient way to conduct our work. We look for the value-add to decide if investing in a new method is worth the effort. How shall we evaluate if we have reached this tipping point for change? For contemporary researchers, under...

The new generation of neutron scattering instruments being built are higher resolution and produce one or more orders of magnitude larger data than the previous generation of instruments. For instance, we have grown out of being able to perform some important tasks with our laptops. The data sizes are too big and the computational time would be too...

We have reinvestigated the β decay of the three isomers of 116Ag at the Holifield Radioactive Ion Beam Facility (HRIBF). Through the use of half-life information, we have been able to construct individual decay schemes for each isomer and correct what was a puzzling inconsistency with the published data, namely the β feeding of 2+ states by a 5+ is...

We have re-investigated the beta decay of the three isomers of ^116Ag to levels in ^116Cd at the HRIBF. Using the CARDS array at UNISOR, we have measured gamma-rays and conversion electrons and their decay times. Through the use of this information, we have been able to construct individual decay schemes for each isomer. Significant deviations are...

Decay losses, associated with the times required for particles to diffuse from ISOL production targets and to effusively-flow to an ion source, must be reduced to as low as practically achievable levels in order to deliver useful beam intensities of short-lived isotopes for research at ISOL based Radioactive Ion Beam (RIB) facilities. We have devel...

An inexpensive, fast, and close to universal infiltration coating technique has been developed for fabricating fast diffusion-release ISOL targets. Targets are fabricated by deposition of finely divided (∼1μm) compound materials in a paint-slurry onto highly permeable, complex structure reticulated-vitreous-carbon-foam (RVCF) matrices, followed by...

A new infiltration coating method has been conceived for uniform and controlled thickness deposition of target materials onto highly permeable, complex-structure matrices to form short-diffusion-length isotope-separator-on-line (ISOL) production targets for radioactive ion beam research applications. In this report, the infiltration technique is de...

A new isomer in 116Ag with a half-life of 20(1) s has been discovered through the use of conversion electron, β, and γ spectroscopy of on-line mass-separated radioactivities at the Holifield Radioactive Ion Beam Facility at ORNL. The observed electron peaks at 22.5, 44.42, and 47.33 keV were interpreted as the K,L, and M conversion electron lines r...

These measurements were carried out at the Holifield Radioactive Ion Beam Facility of the Oak Ridge National Laboratory (ORNL-HRIBF) by researchers from the Istituto Nazionale di Fisica Nucleare - Laboratori Nazionali del Sud (INFN-LNS), Catania, Italy and local staff. The Charge Exchange Cell (CEC) consisted of a vacuum chamber containing cesium v...

Worldwide interest in the use of accelerated radioactive ion beams (RIBs) for exploring reactions important in understanding the structure of the nucleus and nuclear astrophysical phenomena has motivated the construction of facilities dedicated to their production and acceleration. Many facilities utilize the isotope-separator-on-line (ISOL) method...

Although a number of methods have been developed for depositing films of production target materials onto surfaces with thickness commensurate with fast diffusion release of short-lived radioactive species for Isotope Separator On-Line (ISOL) target applications, the methods are either inappropriate for coating interior surfaces of highly permeable...

Radioactive ion beams are produced at the Holifield Radioactive Ion Beam Facility using the ISOL (Isotope Separation On-Line) technique where the atoms are produced in a thick target, transported to an ion source, ionized, and extracted from the ion source to form an ion beam. These radioactive ion beams are then accelerated to energies of a few Me...

Development of ion beams of short-lived isotopes is crucial for modern nuclear structure and nuclear astrophysics. For example, ^82Ge,^130+xSn, ^92,94,95Sr beams are of interest but impurities and low intensities have prevented them from being useful. The code HSC-5 [1], with an extensive thermochemical database, predicts which chemical compounds m...

A series of experiments has been performed to investigate the production of neutron-rich nuclides for decay-spectroscopy purposes at UNISOR Data obtained for the elements Zn through Kr were well fit by a model designed to predict production rates.

The decay of the neutron-rich nucleus 116Ag was studied. Through the use of conversion electron, beta and gamma spectroscopy, we have discovered a new short-lived isomer in 116Ag. The conversion electron data shows previously unknown electron peaks at 22.5, 44.3, and 47.2 keV with half-lives of ~16 seconds each. These are interpreted as the K, L, a...

Results from the study of the beta decay of 116Ag will be presented. This nucleus were studied at the UNISOR separator at the Holifield Radioactive Ion Beam Facility (HRIBF) using the CARDS (Clover Array for Radioactive Decay Spectroscopy) array. For these experiments, the array consists of three segmented clover Ge detectors, three plastic scintil...

An array for decay studies of neutron-rich nuclei has been commissioned for use at the UNISOR separator at Holifield Radioactive Ion Beam Facility. This array consists of three segmented clover Ge detectors, plastic scintillators, and a high-resolution (∼1 keV) Si conversion electron spectrometer. These detectors are mounted on a support that surro...

Nondipole asymmetries of Kr 1s photoelectrons were measured over the 11-8000 eV kinetic-energy range. Symmetry properties of angular distributions were exploited to eliminate the dependence of the measurements on the dipole anisotropy and the polarization properties of the photon beam. The measured asymmetries agree well with both full multipole re...

The beta decay of 116Ag has been studied at the UNISOR separator at HRIBF using the CARDS (Clover Array for Radioactive Decay Spectroscopy) array. This array consists of three segmented clover Ge detectors, plastic scintillators, and a high resolution ( 1 keV) Si conversion electron spectrometer, mounted on a support which surrounds a moving tape c...

The asymmetries of atomic and molecular photoelectrons due to nondipole interactions in the x-ray regime (13-22 keV) were measured and compared with first- and second-order retardation calculations. Symmetry properties of angular distributions were exploited to eliminate the dependence of the measurements on the dipole anisotropy and the polarizati...

The principal factors that limit intensities of short-lived radioactive ion beams produced by the isotope separator on-line technique are time delays due to diffusion of radioactive species from solid or liquid target materials and their effusive-flow transport to the ion source. Although diffusion times can be reduced by proper design of short dif...

An analytical formula has been developed that accurately reproduces Monte Carlo simulations for the effusive-flow transport of chemically active species through tubular transport systems under ideal conditions, independent of species, tube material, and operational temperature. Through its use, the choice of materials ,of construction ,for a given...

Maximum practically achievable intensities are required for research with accelerated radioactive ion beams (RIBs). Time delays due to diffusion of radioactive species from solid or liquid target materials and their effusive-flow transport to the ion source can severely limit intensities of short-lived radioactive beams, and therefore, such delays...

Worldwide interest in the use of accelerated radioactive ion beams (RIBs) for exploring reactions important in understanding the structure of the nucleus and nuclear astrophysical phenomena has motivated the construction of facilities dedicated to their production and acceleration. Many facilities utilize the isotope-separator-on-line (ISOL) method...

The principal factors that severely limit intensities of short-lived radioactive ion beams produced by the Isotope Separator On-Line (ISOL) technique are time delays due to diffusion of radioactive species from solid or liquid target materials and their effusive-flow transport to the ion source. Although diffusion times can be reduced by proper des...

Typical experiments based on the detection of gamma rays are used to measure the production rate and yield of radioactive species produced out of a target material irradiated by a primary beam. Using the number of gamma rays detected, one can deduce the number of radioactive species of interest produced in the target. To do so, a large number of pa...

A relatively simple and inexpensive infiltration coating technique has been developed for depositing refractory target materials onto highly-permeable matrices to form short diffusion-length production targets for ISOL applications. The method is based on a suspension of finely divided (φ: ~1 µm) target materials (e.g. carbides, oxides, sulfides, e...