Verifying the Presence of Low Levels of Neptunium in a Uranium Matrix with Electron Energy-Loss Spectroscopy

Journal Article · Fri Jan 01 04:00:00 EST 2010 · Micron, 41(1):65-70

DOI:https://doi.org/10.1016/j.micron.2009.08.007· OSTI ID:972517

Buck, Edgar C; Douglas, Matthew; Wittman, Richard S

This paper examines the problems associated with the analysis of low levels of neptunium (Np) in a uranium (U) matrix with electron energy-loss spectroscopy (EELS) on the transmission electron microscope (TEM). The detection of Np in a matrix of uranium (U) can be impeded by the occurrence of a plural scattering event from U (U-M5 + U-O4,5) that results in severe overlap on the Np-M5 edge at 3665 eV. Low levels (1600 - 6300 ppm) of Np can be detected in U solids by confirming the energy gap between the Np-M5 and Np-M4 edges is at 184 eV and showing that the M4/M5 ratio for the Np is smaller than that for U. The Richardson-Lucy deconvolution method was applied to energy-loss spectral images and was shown to increase the signal to noise. This method also improves the limits of detection for Np in a U matrix.

• Research Organization: Pacific Northwest National Laboratory (PNNL), Richland, WA (US), Environmental Molecular Sciences Laboratory (EMSL)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-76RL01830
• OSTI ID: 972517
• Report Number(s): PNNL-SA-65803; 24818
• Journal Information: Micron, 41(1):65-70, Journal Name: Micron, 41(1):65-70 Journal Issue: 1 Vol. 41; ISSN 0047-7206; ISSN MICOB5
• Country of Publication: United States
• Language: English

Related Subjects

38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEAR CHEMISTRY
DETECTION
EELS
ENERGY GAP
ENERGY-LOSS SPECTROSCOPY
Environmental Molecular Sciences Laboratory
MATRIX MATERIALS
NEPTUNIUM
Transmission electron microscopy
URANIUM
neptunium
spectroscopy
uranium