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Edwards NP, Bargar JR, van Campen D, van Veelen A, Sokaras D, Bergmann U, Webb SM. A new μ-high energy resolution fluorescence detection microprobe imaging spectrometer at the Stanford Synchrotron Radiation Lightsource beamline 6-2. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2022; 93:083101. [PMID: 36050052 PMCID: PMC9392580 DOI: 10.1063/5.0095229] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2022] [Accepted: 07/14/2022] [Indexed: 06/15/2023]
Abstract
Here, we describe a new synchrotron X-ray Fluorescence (XRF) imaging instrument with an integrated High Energy Fluorescence Detection X-ray Absorption Spectroscopy (HERFD-XAS) spectrometer at the Stanford Synchrotron Radiation Lightsource at beamline 6-2. The X-ray beam size on the sample can be defined via a range of pinhole apertures or focusing optics. XRF imaging is performed using a continuous rapid scan system with sample stages covering a travel range of 250 × 200 mm2, allowing for multiple samples and/or large samples to be mounted. The HERFD spectrometer is a Johann-type with seven spherically bent 100 mm diameter crystals arranged on intersecting Rowland circles of 1 m diameter with a total solid angle of about 0.44% of 4π sr. A wide range of emission lines can be studied with the available Bragg angle range of ∼64.5°-82.6°. With this instrument, elements in a sample can be rapidly mapped via XRF and then selected features targeted for HERFD-XAS analysis. Furthermore, utilizing the higher spectral resolution of HERFD for XRF imaging provides better separation of interfering emission lines, and it can be used to select a much narrower emission bandwidth, resulting in increased image contrast for imaging specific element species, i.e., sparse excitation energy XAS imaging. This combination of features and characteristics provides a highly adaptable and valuable tool in the study of a wide range of materials.
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Affiliation(s)
- Nicholas P. Edwards
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA
| | - John R. Bargar
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA
| | - Douglas van Campen
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA
| | - Arjen van Veelen
- Material Science and Technology Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - Dimosthenis Sokaras
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA
| | - Uwe Bergmann
- Physics Department, University of Wisonsin-Madison, 1150 University Avenue, Madison, Wisconsin 53706-1390, USA
| | - Samuel M. Webb
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA
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Ditter AS, Smiles DE, Lussier D, Altman AB, Bachhav M, He L, Mara MW, Degueldre C, Minasian SG, Shuh DK. Chemical and elemental mapping of spent nuclear fuel sections by soft X-ray spectromicroscopy. JOURNAL OF SYNCHROTRON RADIATION 2022; 29:67-79. [PMID: 34985424 PMCID: PMC8733983 DOI: 10.1107/s1600577521012315] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Accepted: 11/20/2021] [Indexed: 05/03/2023]
Abstract
Soft X-ray spectromicroscopy at the O K-edge, U N4,5-edges and Ce M4,5-edges has been performed on focused ion beam sections of spent nuclear fuel for the first time, yielding chemical information on the sub-micrometer scale. To analyze these data, a modification to non-negative matrix factorization (NMF) was developed, in which the data are no longer required to be non-negative, but the non-negativity of the spectral components and fit coefficients is largely preserved. The modified NMF method was utilized at the O K-edge to distinguish between two components, one present in the bulk of the sample similar to UO2 and one present at the interface of the sample which is a hyperstoichiometric UO2+x species. The species maps are consistent with a model of a thin layer of UO2+x over the entire sample, which is likely explained by oxidation after focused ion beam (FIB) sectioning. In addition to the uranium oxide bulk of the sample, Ce measurements were also performed to investigate the oxidation state of that fission product, which is the subject of considerable interest. Analysis of the Ce spectra shows that Ce is in a predominantly trivalent state, with a possible contribution from tetravalent Ce. Atom probe analysis was performed to provide confirmation of the presence and localization of Ce in the spent fuel.
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Affiliation(s)
- Alexander Scott Ditter
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, One Cyclotron Road, Berkeley, CA 94720, USA
| | - Danil E. Smiles
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, One Cyclotron Road, Berkeley, CA 94720, USA
| | - Daniel Lussier
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, One Cyclotron Road, Berkeley, CA 94720, USA
- Department of Chemistry, University of California Berkeley, 420 Lattimer Hall, Berkeley, CA 94720, USA
| | - Alison B. Altman
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, One Cyclotron Road, Berkeley, CA 94720, USA
- Department of Chemistry, University of California Berkeley, 420 Lattimer Hall, Berkeley, CA 94720, USA
| | - Mukesh Bachhav
- Idaho National Laboratory, 1955 N. Freemont Avenue, Idaho Falls, ID 83415, USA
| | - Lingfeng He
- Idaho National Laboratory, 1955 N. Freemont Avenue, Idaho Falls, ID 83415, USA
| | - Michael W. Mara
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, One Cyclotron Road, Berkeley, CA 94720, USA
- Department of Chemistry, University of California Berkeley, 420 Lattimer Hall, Berkeley, CA 94720, USA
| | - Claude Degueldre
- Department of Engineering, Lancaster University, Lancaster, Lancashire LA1 4YW, United Kingdom
| | - Stefan G. Minasian
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, One Cyclotron Road, Berkeley, CA 94720, USA
| | - David K. Shuh
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, One Cyclotron Road, Berkeley, CA 94720, USA
- Correspondence e-mail:
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Straub MD, Arnold J, Fessenden J, Kiplinger JL. Recent Advances in Nuclear Forensic Chemistry. Anal Chem 2020; 93:3-22. [DOI: 10.1021/acs.analchem.0c03571] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Mark D. Straub
- Department of Chemistry, University of California, Berkeley, California 94720, United States
- Los Alamos National Laboratory, Chemistry Division, Mailstop J-514, Los Alamos, New Mexico 87545, United States
| | - John Arnold
- Department of Chemistry, University of California, Berkeley, California 94720, United States
| | - Julianna Fessenden
- Los Alamos National Laboratory, XTD Division, Los Alamos, New Mexico 87545, United States
| | - Jaqueline L. Kiplinger
- Los Alamos National Laboratory, Chemistry Division, Mailstop J-514, Los Alamos, New Mexico 87545, United States
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