A5079282621- Geological and Geochemical Analysis
- Nuclear Physics and Applications
- Radioactive contamination and transfer
- earthquake and tectonic studies
- Geochemistry and Geologic Mapping
- Geology and Paleoclimatology Research
- Marine and environmental studies
- Geological Modeling and Analysis
- Radioactive element chemistry and processing
- Hydrocarbon exploration and reservoir analysis
- Geological formations and processes
- Nuclear Materials and Properties
- Seismic Imaging and Inversion Techniques
- Geological Studies and Exploration
- High-pressure geophysics and materials
- Radioactivity and Radon Measurements
- Geological Formations and Processes Exploration
- Building materials and conservation
- Atomic and Molecular Physics
- Laser-Matter Interactions and Applications
- Geotechnical and Geomechanical Engineering
- Geological and Tectonic Studies in Latin America
- Drilling and Well Engineering
- Plant Ecology and Soil Science
- Geophysics and Gravity Measurements
Lawrence Livermore National Laboratory
2022-2024
University of Nevada, Reno
2019-2024
Stanford University
2015-2018
Abstract Fission product Sr, Mo, and Ru isotopes in six 10-μm particles of spent fuel from a pressurized water reactor were analyzed by resonance ionization mass spectrometry (RIMS) evaluated for utility nuclear material characterization. Previous measurements on these same samples showed widely varying U, Pu, Am isotopic compositions owing to the samples’ differing irradiation environments within reactor. This is also seen Mo isotopes, which have added complication exsolution UO 2 matrix....
Abstract Dehydration reactions within subducted oceanic crust are important for fluid‐mediated element transfer the subducting plate and potentially to mantle wedge. The effects of metamorphic fluid flow on recycling that occur during retrogression exhumation continental from depths poorly understood. We study two metabasite pods with fresh eclogite cores retrogressed amphibolite‐facies rims surrounding host gneiss Western Gneiss Region (WGR), Norway, better understand mobility mass crust....
Uranium interference is a major problem in conventional 238 Pu analysis. In RIMS, slight detuning of the resonance laser extinguishes signal so that U can be accurately quantified and subtracted.
A new zirconium resonance ionization scheme reveals shifting isotope ratios in spent nuclear fuel towards the pellets edge.
Finely acicular rutile intergrown with host quartz (rutilated quartz) is commonly found in hydrothermal veins, including the renown cleft mineral locations of Swiss Alps. These Alpine mineralizations reportedly formed between ∼13.5 and 15.2 Ma (based on ages rare monazite titanite) at temperatures (T) ∼150-450 °C fluid inclusions bulk quartz-mineral oxygen isotope exchange equilibria), pressures (P) 0.5-2.5 kbar (estimated from a geothermal gradient 30 °C/km). The potential rutilated as...
Microscopic fuel fragments, so-called "hot particles", were released during the 1986 accident at Chornobyl nuclear powerplant and continue to contaminate exclusion zone in northern Ukraine. Isotopic analysis can provide vital information about sample origin, history contamination of environment, though it has been underutilized due destructive nature most mass spectrometric techniques, inability remove isobaric interference. Recent developments have diversified range elements that be...
While resonance ionization mass spectrometry (RIMS) has demonstrated utility in measuring isotopic compositions of elements complex matrices without the need for chemical separation to remove isobaric interferences, it had limited application elemental compositions. The ability determine via an situ method like RIMS would be exceptional asset spent nuclear fuel analysis, where they are important assessing reactor histories and whose presents a radiological hazard. However, quantitative...
Microscopic fuel fragments, so-called ``hot particles'', were released during the 1986 accident at Chornobyl nuclear powerplant and continue to contaminate exclusion zone in northern Ukraine. Origin, age, environmental weathering of material can be determined via isotopic analysis, providing vital information about sample history contamination environment. A comprehensive study structure composition single hot particles from Exclusion Zone (CEZ) was made using isotope ratios actinides...
Abstract Measuring the isotopic composition of trace Zr in presolar stardust grains allows us to study environment slow neutron-capture nucleosynthesis asymptotic giant branch stars. Here, we present a newly characterized resonance ionization scheme that can be saturated with state-of-the-art titanium-sapphire lasers and yields useful yield (5.4 ± 0.4)%. Resonance is achieved two steps: after first being excited photon at 319.215 nm, neutral atoms are then ionized 388.988 where both...