A5046730997- Radioactive contamination and transfer
- Radioactive element chemistry and processing
- Nuclear Physics and Applications
- Radioactivity and Radon Measurements
- Nuclear Materials and Properties
- Ion-surface interactions and analysis
- Nuclear reactor physics and engineering
- Nuclear and radioactivity studies
- NMR spectroscopy and applications
- Hemoglobin structure and function
- Geochemistry and Geologic Mapping
- Legume Nitrogen Fixing Symbiosis
- Mass Spectrometry Techniques and Applications
- Laser-induced spectroscopy and plasma
- Vibrio bacteria research studies
Lawrence Livermore National Laboratory
2024-2025
Leibniz University Hannover
2019-2023
Gottfried-Wilhelm-Leibniz-Gesellschaft
2019
Radiation Protection Institute
2019
The isotopic ratios of fission gas would provide important source information a nuclear fuel sample found in the environment. However, it is believed that during reactor accident like Chornobyl all lost and radioactive particles Exclusion Zone today are depleted gases by initial explosion subsequent fire. We disprove this hypothesis detection analysis trapped krypton xenon these particles. Our isotopes noble mass spectroscopy combination with resonance ionization spectrometry establishes...
The isotopic ratios of fission gas would provide important source information a nuclear fuel sample found in the environment. However, it is believed that during reactor accident like Chornobyl all lost and radioactive particles Exclusion Zone today are depleted gases by initial explosion subsequent fire. We disprove this hypothesis detection analysis trapped krypton xenon these particles. Our isotopes noble mass spectroscopy combination with resonance ionization spectrometry establishes...
Quasi non-desctructive actinide isotope detection and imaging on the 100nm scale advances single particle nuclear forensics.
Radioactive particles, so-called hot are of great importance in the risk assessment environmental pollution and human health hazards. Since most these particles only a couple micrometers size thus have correspondingly small atomic inventory, information on origin composition is difficult to obtain. Many analytical methods do not give insight into isotopic details or require complete use up particle. Resonant laser secondary neutral mass spectrometry (rl-SNMS) has been proven be well-suited...
A new zirconium resonance ionization scheme reveals shifting isotope ratios in spent nuclear fuel towards the pellets edge.
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...
Abstract Strains of the Gram-negative bacterium Vibrio coralliilyticus cause bleaching corals due to decomposition symbiotic microalgae. The V. strain ATCC BAA-450 (Vc450) encodes a type III secretion system (T3SS). gene cluster also protein (locus tag VIC_001052) with sequence homology T3SS-secreted nodulation proteins NopE1 and NopE2 Bradyrhizobium japonicum (USDA110). VIC_001052 has been shown undergo auto-cleavage in presence Ca 2+ similar NopE proteins. We have studied hitherto unknown...
Cellulosic materials present as tissue, paper, wood, or filter in low and intermediate level waste will degrade under alkaline conditions if water ingresses a cementitious backfilled repository. The main degradation product is isosaccharinic acid. Complex formation with acid may adversely affect the retention of radionuclides by sorption solid phases. Hence, this compound particular concern context nuclear disposal. Structural information complexes limited to spherical metal centers little...
Abstract Resonance ionization mass spectrometry is an ultra-sensitive and highly element selective tool for spectroscopy, detection of atoms thus enables rare isotope determination. In combination with spatially resolved sputtering neutrals by initial ion beam, e.g. within a commercial secondary spectrometer, isobar analysis technique resolution on the micrometer scale particles surfaces realized. Detection minuscule amounts specific actinides, plutonium, in environmental technical samples...
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...
Radiometric or mass spectrometric analysis of the long-lived fission product 107Pd is notoriously difficult. We developed and optimized a chemical separation protocol for minute amounts radiopalladium with subsequent measurement by inductively coupled plasma triple quadrupole spectrometry propane as collision gas. This allows detection limits <2 ng 107Pd/kg, which makes method suitable environmental samples low levels 107Pd. For testing this method, sample sediment from Chernobyl cooling...
In this study the complexation of U(VI) with orthosilicic acid (H4SiO4) was investigated between pH 3.5 and 5 by combining electrospray ionization mass spectrometry (ESI-MS) laser-induced luminescence spectroscopy. The ESI-MS experiments performed at a total silicon concentration · 10-3M (exceeding solubility amorphous silica both pH-values) revealed formation oligomeric sodium-silicates in addition to UO2OSi(OH)3+ species. For spectroscopic (25 °C), fixed 10-6M, varied 1.3 10-4-1.3...
Abstract In this work, uranium-and plutonium-baring particles were produced by fast iron co-precipitation for the purpose of creating homogeneous multi-element standards. A set single isolated showing no inhomogeneities in element distribution selected. These used to determine maximal achievable suppression ratios uranium Resonant Laser Secondary Neutral Mass Spectrometry (rL-SNMS) measurements plutonium. It was shown first time directly that suppression-ratios order three magnitudes are...
Zusammenfassung Durch die Kombination von Resonanzionisation und kommerzieller Sekundärionen‐Massenspektrometrie ist es möglich, elementare Zusammensetzung Isotopenverhältnisse kleinsten Partikeln zu bestimmen. Dabei erlaubt Auswahl geeigneter Anregungsleitern effektive Unterdrückung isobarer Störungen. Das Verfahren kann eingesetzt werden, um den Ursprungsreaktor Kernbrennstofffragmenten in der Umwelt identifizieren. Im Zuge aktuellen Ereignisse Ukraine lassen sich auf diese Weise alte...