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Displaying 1 - 25 of 36

Energy Broadening of Neutron Depth Profiles by Thin Polyamide Films

September 7, 2022
Author(s)
Jamie Weaver, Anna Job, Kedar Manandhar, Ichiro Takeuchi, Robert Gregory Downing
A protective covering is often required for neutron depth profiling (NDP) measurements of sensitive materials (e.g., Li-ion batteries). Addition of this layer can increase NDP profile energy broadening and depth assignment uncertainty. This study evaluates

Near-Surface Elemental Analysis of Solids by Neutron Depth Profiling

December 31, 2018
Author(s)
Jamie Weaver, Robert Gregory Downing
Neutron Depth Profiling (NDP) is an analytical nuclear technique for the determination of elemental mass as a function of depth into a sample's surface. It is suitable for characterizing a few select elements in most solid materials to depths of

A 3He beam stop for minimizing gamma-ray and fast-neutron background

August 6, 2016
Author(s)
Danyal J. Turkoglu, Robert G. Downing, Wangchun Chen, Dagistan Sahin, Jeremy C. Cook
Prompt gamma-ray activation analysis facilities with high neutron currents (≥109 s-1) generate triton-induced fast neutrons from 6Li-loaded collimators and beam stops at rates that soon damage gamma-ray detectors. We develop an alternative beam stop design

In Situ Neutron Techniques for Studying Lithium Ion Batteries

May 1, 2012
Author(s)
Howard Wang, Robert Gregory Downing, Joseph Dura, Daniel S. Hussey
We review in situ neutron techniques for studying lithium ion batteries. Four neutron measurement techniques, neutron depth profiling (NDP), neutron reflectivity (NR), small angle neutron scattering (SANS), and neutron imaging (NI) are discussed in this

Neutron Depth Profiling Technique for Studying Aging in Li-ion Batteries

February 15, 2011
Author(s)
Robert G. Downing
During operation of a Li-ion cell, lithium diffuses in and out of the solid phase anode and cathode. Measuring the lithium transport within the cell over its operational life could provide key information for understanding the loss of active lithium and

Observation of Phase Transitions in Hydrogenated Y Films Via IR Emissivity Imaging

October 20, 2009
Author(s)
Jason Hattrick-Simpers, Ke Wang, Raymond Cao, Chun Chiu, Edwin J. Heilweil, Robert G. Downing, Leonid A. Bendersky
Direct observation of a sequence of phase transitions during hydrogenation of Y thin films has been realized through the use of in-situ isothermal IR emissivity measurements. The formation of different phases, α-Y(H), YH2 and YH3, has been identified based

Combinatorial Study of Thin Film Metal Hydride by Prompt Gamma Activation Analysis

June 19, 2009
Author(s)
Raymond Cao, Jason Hattrick-Simpers, Richard Bindel, Bryan E. Tomlin, Rolf L. Zeisler, Rick L. Paul, Leonid A. Bendersky, Robert G. Downing
Cold neutron prompt gamma activation analysis (PGAA) was used to determine the amount of hydrogen in thin film Mg hydrides with varying hydrogenation times. The results suggest that the hydrogenation in the Mg thin films remains unsaturated even after 48

Advancement of Light-Element Neutron Depth Profiling at the University of Texas

April 1, 2008
Author(s)
S M. Whitney, Robert Gregory Downing, S Biegalski, D S. O'Kelly
The University of Texas (UT) at Austin has collaborated with the National Institute of Standards and Technology for comparisons of concentration versus depth profiles of samples containing 10B. Technology sharing from NIST has allowed UT to avoid many

Neutron Collimation With Microchannel Plates: Calibration of Existing Technology and Near

April 1, 2007
Author(s)
A S. Tremsin, Daniel S. Hussey, David L. Jacobson, Muhammad D. Arif, Robert Gregory Downing, W B. Feller, David F. Mildner
A new type of high performance and compact neutron collimator can be manufactured from Gd- or B-doped microchannel plates (MCPs). Structures only a few mm thick have very narrow rocking curves and high out-of-angle rejection ratios, as observed previously

Development of Certified Reference Materials of Ion-Implanted Dopants in Silicon for Calibration of Secondary Ion Mass Spectrometers

January 1, 2007
Author(s)
David S. Simons, Robert G. Downing, George P. Lamaze, Richard M. Lindstrom, Robert R. Greenberg, Rick L. Paul, Susannah Schiller, William F. Guthrie
Certified reference materials have been developed for calibration of the concentrations of the most common dopants used in silicon semiconductor technology boron, arsenic, and phosphorus. These materials consist of a single dopant species that is