A5038242575- Astro and Planetary Science
- Groundwater and Isotope Geochemistry
- Methane Hydrates and Related Phenomena
- Geology and Paleoclimatology Research
- Solar and Space Plasma Dynamics
- Hydrocarbon exploration and reservoir analysis
- Planetary Science and Exploration
- Spacecraft and Cryogenic Technologies
- Atmospheric and Environmental Gas Dynamics
- Nuclear Physics and Applications
- Geological and Geochemical Analysis
- Atmospheric Ozone and Climate
- Paleontology and Stratigraphy of Fossils
- Molten salt chemistry and electrochemical processes
- Quantum, superfluid, helium dynamics
- Graphite, nuclear technology, radiation studies
- Isotope Analysis in Ecology
- Radioactivity and Radon Measurements
- Atomic and Subatomic Physics Research
- Hydrogen Storage and Materials
- Radioactive contamination and transfer
- Cold Atom Physics and Bose-Einstein Condensates
- Light effects on plants
- Radiative Heat Transfer Studies
- Calibration and Measurement Techniques
International Atomic Energy Agency
2017-2024
Argonne National Laboratory
2024
University of Oxford
2016-2021
Centre de Recherches Pétrographiques et Géochimiques
2012-2018
Centre National de la Recherche Scientifique
2012-2018
Université de Lorraine
2015-2018
Washington University in St. Louis
2006-2008
California Institute of Technology
2007
Los Alamos National Laboratory
2007
University of Montana
2007
Helium has two natural isotopes which have contrasted, and variable sources sinks in the atmosphere (3He/4Heair = 1.382 ± 0.005 × 10−6). Variations atmospheric helium isotopic composition may exist below typical measurement precision thresholds (0.2 to 0.5%, 2σ). In order investigate this possibility, it is necessary be able consistently measure air with high (below 0.2% We created an purification system that improves isotope precision. By purifying a large quantity of at start cycle we can...
To evaluate the isotopic composition of solar nebula from which planets formed, relation between isotopes measured in wind and on Sun's surface needs to be known. The Genesis Discovery mission returned independent samples three types produced by different processes that provide a check possible variations, or fractionation, solar-wind solar-surface material. At high level precision, we observed no significant inter-regime differences 20Ne/22Ne 36Ar/38Ar values. For 20Ne/22Ne, difference low-...
Geochemical characteristics in subsurface fluid systems provide a wealth of information about sources, migration, and storage conditions. Determining the extent interaction (aquifer-hydrocarbon connectivity) is important for oil gas production waste applications, but not tractable using traditional seismic methods. Furthermore, residence time fluids critical such can vary from tens thousands to billions years. Our understanding transport length scales multiphase systems, while equally...
Spatial variations in the atmospheric helium isotopic composition (RA = 3He/4Heair 1.39 × 10−6) might be induced by localized and/or regional inputs of 3He 4He into air. It has been suggested that from hydrocarbon exploitation may generate latitudinal 3He/4He. In order to test possibility such global variations, we performed high precision analyses (3He/4He) sixteen air samples collected 500 cc metal bottles around world (79°N–75°S) between 2013 and 2015. most cases, 3He/4He these are...
Tuning a Nier-type ion source involves adjusting many different parameters which affect the resulting signal in complicated ways. We have mapped sensitivity of 4He and peak shape while varying total extraction voltage, half-plate bias, repeller electron energy. With particular settings that we used, see an asymmetric rise fall as is raised, but symmetric bias voltage varied. The best found generally at same value maximum sensitivity, distinctly than sensitivity; thus it necessary to monitor...
A paleo-megafan system of the Cubango River in northern parts semi-arid Cuvelai-Etosha Basin, shared by Angola and Namibia. It hosts a deep freshwater aquifer, so-called Kalahari-Ohangwena 2 (KOH-2), with potential to resolve imminent regional water supply shortages. Hydrogeochemical multi-environmental tracer studies incorporating use age tracers 14C, 36Cl, 81Kr 4He determine groundwater provide insights into flow dynamics KOH-2. Stable isotopes noble gas thermometry show that period higher...
The composition of atmospheric helium is generally considered to be constant ( 3 He/ 4 He = 1.39 × 10 − 6 ) on a large spatial scale. However, local variations may arise in tectonically active areas due focussed degassing one its two isotopes, for example mantle-derived or crustal-derived He. If detected, such have the potential trace open conduit magmatic bodies and/or diffusive emissions from volcanic crustal sources. Here, we test possibility detecting Afar region north-eastern Ethiopia,...
Krypton-81 was applied to investigate the age of groundwater in aquifer system Bangkok metropolitan and vicinity areas. Stable (2H, 18O 13C) radioactive (3H, 85Kr 14C) isotopes noble gases were parallel. Low levels 14C significant radiogenic 4He confirm that deep aquifers is older than 30 ka. 81Kr analysis identified with ages ranging from 17 300 At some sites, large discrepancies between indicated inter-aquifer mixing likely occurring. The interpretation suggests groundwaters deeper...
Abstract For much of the pelagic sedimentary record, time control is limited to resolution precession cycles ( ca 20 kyr): Milankovitch parameter that forms most detailed metronome for Cenozoic and Mesozoic Eras. The influence often detected in lithological alternations, where duration represented by individual lithologies not well constrained. Here novel technique extraterrestrial helium abundance 3 He ET ) used investigate sedimentation dynamics palaeoceanography within precessional...
The long-lived radio-krypton isotope 81Kr (t1/2 = 2.29 × 105 yr) is an ideal tracer for old groundwater age dating in the range of 105-106 years which goes beyond reach radio-carbon (14C) dating. Analytical breakthrough made over last two decades Atom Trap Trace Analysis (ATTA) has enabled use this with extremely low abundance (81Kr/Kr 6 10-13) to be used as a practical tool very groundwater. International Atomic Energy Agency aims provide new better resource management Member States and...