ORCID Profile
0000-0001-6014-0126
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Research Topics
In Research Link Australia (RLA), "Research Topics" refer to ANZSRC FOR and SEO codes. These topics are either sourced from ANZSRC FOR and SEO codes listed in researchers' related grants or generated by a large language model (LLM) based on their publications.
Top 5 Research Topics
ANZSRC Field of Research (FoR)
Synchrotrons; Accelerators; Instruments and Techniques | Soil Sciences | Astronomical and Space Sciences not elsewhere classified | Sedimentology | Nuclear Physics | Nuclear physics | Atomic, Molecular, Nuclear, Particle and Plasma Physics | Nuclear and plasma physics | Law and society and socio-legal research | Geology | Land Capability And Soil Degradation | Applied Hydrology (Drainage, Flooding, Irrigation, Quality, Etc.) | Environmental Management And Rehabilitation | Mineral processing/beneficiation | Instruments And Techniques | Other Physical Sciences | Environmental Management | Land Capability and Soil Degradation | Particle Physics |
ANZSRC Socio-Economic Objective (SEO)
Expanding Knowledge in the Physical Sciences | Emerging Defence Technologies | Land and water management | Marine protected areas | Nuclear Energy | Land and water management | Land and water management | Expanding Knowledge in the Chemical Sciences | Scientific Instruments | Farmland, Arable Cropland and Permanent Cropland Land Management | Forest and Woodlands Land Management
Related Links
Publications
Time-resolved record of 236U and 239,240Pu isotopes from a coral growing during the nuclear testing program at Enewetak Atoll (Marshall Islands)
Publisher: Elsevier BV
Date: 12-2016
DOI: 10.1016/J.JENVRAD.2016.09.015
Abstract: A comprehensive series of nuclear tests were carried out by the United States at Enewetak Atoll in the Marshall Islands, especially between 1952 and 1958. A Porites Lutea coral that was growing in the Enewetak lagoon within a few km of all of the high-yield tests contains a continuous record of isotopes, which are of interest (e.g.
In situ cosmogenic 53Mn production rate from ancient low-denudation surface in tropic Brazil
Publisher: Elsevier BV
Date: 04-2010
93Zr developments at the Heavy Ion Accelerator Facility at ANU
Publisher: Elsevier BV
Date: 2019
Background reduction in 236U/238U measurements
Publisher: Elsevier BV
Date: 10-2015
No Fukushima Dai-ichi derived plutonium signal in marine sediments collected 1.5–57 km from the reactors
Publisher: Elsevier BV
Date: 11-2017
DOI: 10.1016/J.APRADISO.2017.08.015
Abstract: Based on AMS analysis, it is shown that no Pu signals from the Fukushima accident could be discerned in marine sediments collected 1.5-57km away from the Fukushima Da-ichi power plant (FDNPP), which were clearly influenced by accident-derived radiocesium. The
Late Pleistocene glacial stratigraphy of the Kumara-Moana region, West Coast of South Island, New Zealand
Publisher: Elsevier BV
Date: 08-2013
AMS of natural 236U and 239Pu produced in uranium ores
Publisher: Elsevier BV
Date: 06-2007
First measurements of 236U concentrations and 236U/239Pu isotopic ratios in a Southern Hemisphere soil far from nuclear test or reactor sites
Publisher: Elsevier BV
Date: 06-2014
DOI: 10.1016/J.JENVRAD.2014.02.022
Abstract: The variation of the (236)U and (239)Pu concentrations as a function of depth has been studied in a soil profile at a site in the Southern Hemisphere well removed from nuclear weapon test sites. Total inventories of (236)U and (239)Pu as well as the (236)U/(239)Pu isotopic ratio were derived. For this investigation a soil core from an undisturbed forest area in the Herbert River catchment (17°30' - 19°S) which is located in north-eastern Queensland (Australia) was chosen. The chemical separation of U and Pu was carried out with a double column which has the advantage of the extraction of both elements from a relatively large soil s le (∼20 g) within a day. The s les were measured by Accelerator Mass Spectrometry using the 14UD pelletron accelerator at the Australian National University. The highest atom concentrations of both (236)U and (239)Pu were found at a depth of 2-3 cm. The (236)U/(239)Pu isotopic ratio in fallout at this site, as deduced from the ratio of the (236)U and (239)Pu inventories, is 0.085 ± 0.003 which is clearly lower than the Northern Hemisphere value of ∼0.2. The (236)U inventory of (8.4 ± 0.3) × 10(11) at/m(2) was more than an order of magnitude lower than values reported for the Northern Hemisphere. The (239)Pu activity concentrations are in excellent agreement with a previous study and the (239+240)Pu inventory was (13.85 ± 0.29) Bq/m(2). The weighted mean (240)Pu/(239)Pu isotopic ratio of 0.142 ± 0.005 is slightly lower than the value for global fallout, but our results are consistent with the average ratio of 0.173 ± 0.027 for the southern equatorial region (0-30°S).
Settling the Half-Life ofFe
Publisher: American Physical Society (APS)
Date: 28-01-2015
Plutonium isotope measurements from across continental Australia
Publisher: Elsevier BV
Date: 2013
239Pu fallout across continental Australia: Implications on 239Pu use as a soil tracer
Publisher: Elsevier BV
Date: 11-2017
DOI: 10.1016/J.JENVRAD.2017.08.009
Abstract: At present there is a need for the development of new radioisotopes for soil erosion and sediment tracing especially as fallout
Measurements of Pu and Ra isotopes in soils and sediments by AMS
Publisher: Elsevier BV
Date: 08-2004
Using239Pu as a tracer for fine sediment sources in the Daly River, Northern Australia
Publisher: EDP Sciences
Date: 2015
Uranium comparison by means of AMS and ICP-MS and Pu and137Cs results around an Italian Nuclear Power Plant
Publisher: EDP Sciences
Date: 2015
Novel matching lens and spherical ionizer for a cesium sputter ion source
Publisher: Springer Science and Business Media LLC
Date: 12-2002
Nuclear weapons produced 236U, 239Pu and 240Pu archived in a Porites Lutea coral from Enewetak Atoll
Publisher: Elsevier BV
Date: 11-2017
DOI: 10.1016/J.JENVRAD.2017.05.009
Abstract: A slice from a Porites Lutea coral core collected inside the Enewetak Atoll lagoon, within 15 km of all major nuclear tests conducted at the atoll, was analysed for
Further constraint of the in situ cosmogenic 10Be production rate in pyroxene and a viability test for late Quaternary exposure dating
Publisher: Elsevier BV
Date: 10-2018
Anthropogenic 236U and Pu at remote sites of the South Pacific
Publisher: Elsevier BV
Date: 09-2019
DOI: 10.1016/J.JENVRAD.2019.05.003
Abstract: Anthropogenic radionuclides, like
Preparation of a multi-isotope plutonium AMS standard and preliminary results of a first inter-lab comparison
Publisher: Elsevier BV
Date: 10-2015
Applicability of 239Pu as a tracer for soil erosion in the wet-dry tropics of northern Australia
Publisher: Elsevier BV
Date: 2013
Plutonium as a chronomarker in Australian and New Zealand sediments: a comparison with 137Cs
Publisher: Elsevier BV
Date: 10-2011
DOI: 10.1016/J.JENVRAD.2009.09.008
Abstract: The construction of high resolution chronologies of sediment profiles corresponding to the last 50-100 years usually entails the measurement of fallout radionuclides (210)Pb and (137)Cs. The anthropogenic radionuclide, (137)Cs, originating from atmospheric nuclear weapons testing can provide an important "first appearance" horizon of known age (1954-1955), providing much-needed validation for the sometimes uncertain interpretations associated with (210)Pb geochronology. However, while (137)Cs usually provides a strong signal in sediment in the northern hemisphere, total fallout of (137)Cs in the southern hemisphere was only 25% that of the north and the low activities of (137)Cs seen in Australian and New Zealand sediments can make its horizon of first appearance somewhat arguable. Low (137)Cs fallout also limited the size of the 1963-1964 fallout peak, a peak that is usually seen in northern hemisphere sediment profiles but is often difficult to discern south of the equator. This paper shows ex les of the use of nuclear weapons fallout Pu as a chronomarker in sediment cores from Australia (3 sites) and New Zealand (1 site). The Pu profiles of five cores are examined and compared with the corresponding (137)Cs profiles and (210)Pb geochronologies. We find that Pu has significant advantages over (137)Cs, including greater measurement sensitivity using alpha spectrometry and mass spectrometric techniques compared to (137)Cs measurements by gamma spectrometry. Moreover, Pu provides additional chronomarkers associated with changes in the Pu isotopic composition of fallout during the 1950s and 1960s. In particular, the (238)Pu/(239+240)Pu activity ratio shows distinct shifts in the early 1950s and the mid to late 1960s, providing important known-age horizons in southern hemisphere sediments. For estuarine and near-shore sediments Pu sometimes has another significant advantage over (137)Cs due to its enrichment in bottom sediment relative to (137)Cs resulting from the more efficient scavenging of dissolved Pu in seawater by sediment particles.
Accelerator mass spectrometry with the 14UD accelerator at the Australian National University
Publisher: Elsevier BV
Date: 04-2010
The release and persistence of radioactive anthropogenic nuclides
Publisher: Geological Society of London
Date: 2014
DOI: 10.1144/SP395.15
Long-range tropospheric transport of uranium and plutonium weapons fallout from Semipalatinsk nuclear test site to Norway
Publisher: Elsevier BV
Date: 09-2013
DOI: 10.1016/J.ENVINT.2013.05.017
Abstract: A combination of state-of-the-art isotopic fingerprinting techniques and atmospheric transport modelling using real-time historical meteorological data has been used to demonstrate direct tropospheric transport of radioactive debris from specific nuclear detonations at the Semipalatinsk test site in Kazakhstan to Norway via large areas of Europe. A selection of archived air filters collected at ground level at 9 stations in Norway during the most intensive atmospheric nuclear weapon testing periods (1957-1958 and 1961-1962) has been screened for radioactive particles and analysed with respect to the concentrations and atom ratios of plutonium (Pu) and uranium (U) using accelerator mass spectrometry (AMS). Digital autoradiography screening demonstrated the presence of radioactive particles in the filters. Concentrations of (236)U (0.17-23nBqm(-3)) and (239+240)Pu (1.3-782μBqm(-3)) as well as the atom ratios (240)Pu/(239)Pu (0.0517-0.237) and (236)U/(239)Pu (0.0188-0.7) varied widely indicating several different sources. Filter s les from autumn and winter tended to have lower atom ratios than those s led in spring and summer, and this likely reflects a tropospheric influence in months with little stratospheric fallout. Very high (236)U, (239+240)Pu and gross beta activity concentrations as well as low (240)Pu/(239)Pu (0.0517-0.077), (241)Pu/(239)Pu (0.00025-0.00062) and (236)U/(239)Pu (0.0188-0.046) atom ratios, characteristic of close-in and tropospheric fallout, were observed in filters collected at all stations in Nov 1962, 7-12days after three low-yield detonations at Semipalatinsk (Kazakhstan). Atmospheric transport modelling (NOAA HYSPLIT_4) using real-time meteorological data confirmed that long range transport of radionuclides, and possibly radioactive particles, from Semipalatinsk to Norway during this period was plausible. The present work shows that direct tropospheric transport of fallout from atmospheric nuclear detonations periodically may have had much larger influence on radionuclide air concentrations and deposition than previously anticipated.
Plutonium AMS measurements in Yangtze River estuary sediment
Publisher: Elsevier BV
Date: 04-2010
Late Pleistocene glaciation of the Mt Giluwe volcano, Papua New Guinea
Publisher: Elsevier BV
Date: 09-2011
Comparison of Pu and 137Cs as tracers of soil and sediment transport in a terrestrial environment
Publisher: Elsevier BV
Date: 02-2008
DOI: 10.1016/J.JENVRAD.2007.10.019
Abstract: Following atmospheric nuclear weapons testing in the 1950s and 1960s significant quantities of (137)Cs and (239+240)Pu were deposited worldwide. In recent decades, (137)Cs has been commonly used as a tracer of soil erosion and sedimentation, particularly in the Northern Hemisphere where atomic deposition was three times as great as in the Southern Hemisphere. The relatively short 30-year half-life of this isotope means that its sensitivity as a tracer is rapidly decreasing. In contrast, with half-lives of 24,110 and 6561 years, the sensitivity of the two plutonium isotopes remains essentially the same as when it was deposited. Here we use the technique of Accelerator Mass Spectrometry to demonstrate the potential of anthropogenic Pu as an alternative to (137)Cs as a tracer of soil transport in Australia. We measure an average (137)Cs/(239+240)Pu activity ratio of 27.3+/-1.5 and an average (240)Pu/(239)Pu atom ratio of 0.149+/-0.003, both slightly lower than the global average.
Plutonium as a tracer of soil and sediment movement in the Herbert River, Australia
Publisher: Elsevier BV
Date: 04-2010
10Be-derived denudation rates from the Burdekin catchment: The largest contributor of sediment to the Great Barrier Reef
Publisher: Elsevier BV
Date: 07-2015
Measurements of low-level anthropogenic radionuclides from soils around Maralinga
Publisher: EDP Sciences
Date: 2013
Accelerator mass spectrometry measurement of the reaction
Cl
Publisher:
American Physical Society (APS)
Date:
08-01-2019
Publisher: American Physical Society (APS)
Date: 08-01-2019
60 Fe deposition during the late Pleistocene and the Holocene echoes past supernova activity
Publisher: Proceedings of the National Academy of Sciences
Date: 24-08-2020
Abstract: Nearby supernova explosions shape the interstellar medium. Ejecta, containing fresh nucleosynthetic products, may traverse the solar system as a transient passage, or alternatively the solar system may traverse local clouds that may represent isolated remnants of supernova explosions. Such scenarios may modulate the galactic cosmic-ray flux intensity to which Earth is exposed. Varying conditions of the traversed interstellar medium could have impacts on climate and can be imprinted in the terrestrial geological record. Some radionuclides, such as 60 Fe, are not produced on Earth or within the solar system in significant quantities. Their existence in deep-sea sediments demonstrates recent production in close-by supernova explosions with a continued influx of 60 Fe until today.
Using fallout plutonium as a probe for erosion assessment
Publisher: Elsevier BV
Date: 10-2011
DOI: 10.1016/J.JENVRAD.2010.06.010
Abstract: A study has been carried out to assess the potential of using fallout plutonium (Pu), which originated from atmospheric nuclear-weapons tests, as a tool to investigate recent erosional processes within the lower Cotter water-supply catchment in the Australian Capital Territory. This catchment, which was predominantly pine plantation, was severely affected by a major bush fire in 2003. Accelerator mass spectrometry has been used to measure Pu in soil s les collected from a number of sites across the catchment. The results indicate that less than 1cm of surface soil had been lost since the early 1960s over much of the catchment. Areas of more erodible soil have, however, lost 2-4cm of topsoil, and a loss of ∼6cm of soil was identified at one particular site.
Developments in AMS of 99Tc
Publisher: Elsevier BV
Date: 08-2004
Determination of total I and129I concentrations in freshwater of Argentina
Publisher: EDP Sciences
Date: 2013
Backgrounds and blanks in Iodine-129 measurements at the Australian National University
Publisher: Elsevier BV
Date: 11-2022
129I in rainwater across Argentina
Publisher: Elsevier BV
Date: 07-2022
DOI: 10.1016/J.JENVRAD.2022.106871
Abstract: Concentrations of
Accelerator mass spectrometry with ANU’s 14 million volt accelerator
Publisher: Elsevier BV
Date: 2023
Transport of low 240Pu/239Pu atom ratio plutonium-species in the Ob and Yenisey Rivers to the Kara Sea
Publisher: Elsevier BV
Date: 11-2006
Continuous transport of Pacific-derived anthropogenic radionuclides towards the Indian Ocean
Publisher: Springer Science and Business Media LLC
Date: 17-03-2017
DOI: 10.1038/SREP44679
Abstract: Unusually high concentrations of americium and plutonium have been observed in a sediment core collected from the eastern Lombok Basin between Sumba and Sumbawa Islands in the Indonesian Archipelago. Gamma spectrometry and accelerator mass spectrometry data together with radiometric dating of the core provide a high-resolution record of ongoing deposition of anthropogenic radionuclides. A plutonium signature characteristic of the Pacific Proving Grounds (PPG) dominates in the first two decades after the start of the high yield atmospheric tests in 1950’s. Approximately 40–70% of plutonium at this site in the post 1970 period originates from the PPG. This sediment record of transuranic isotopes deposition over the last 55 years provides evidence for the continuous long-distance transport of particle-reactive radionuclides from the Pacific Ocean towards the Indian Ocean.
The 240Pu/239Pu atom ratio in Chinese soils
Publisher: Elsevier BV
Date: 08-2019
DOI: 10.1016/J.SCITOTENV.2019.04.251
Abstract: The
Chronology of Pu isotopes and 236U in an Arctic ice core
Publisher: Elsevier BV
Date: 09-2013
DOI: 10.1016/J.SCITOTENV.2013.05.054
Abstract: In the present work, state of the art isotopic fingerprinting techniques are applied to an Arctic ice core in order to quantify deposition of U and Pu, and to identify possible tropospheric transport of debris from former Soviet Union test sites Semipalatinsk (Central Asia) and Novaya Zemlya (Arctic Ocean). An ice core chronology of (236)U, (239)Pu, and (240)Pu concentrations, and atom ratios, measured by accelerator mass spectrometry in a 28.6m deep ice core from the Austfonna glacier at Nordaustlandet, Svalbard is presented. The ice core chronology corresponds to the period 1949 to 1999. The main sources of Pu and (236)U contamination in the Arctic were the atmospheric nuclear detonations in the period 1945 to 1980, as global fallout, and tropospheric fallout from the former Soviet Union test sites Novaya Zemlya and Semipalatinsk. Activity concentrations of (239+240)Pu ranged from 0.008 to 0.254 mBq cm(-2) and (236)U from 0.0039 to 0.053 μBq cm(-2). Concentrations varied in concordance with (137)Cs concentrations in the same ice core. In contrast to previous published results, the concentrations of Pu and (236)U were found to be higher at depths corresponding to the pre-moratorium period (1949 to 1959) than to the post-moratorium period (1961 and 1962). The (240)Pu/(239)Pu ratio ranged from 0.15 to 0.19, and (236)U/(239)Pu ranged from 0.18 to 1.4. The Pu atom ratios ranged within the limits of global fallout in the most intensive period of nuclear atmospheric testing (1952 to 1962). To the best knowledge of the authors the present work is the first publication on biogeochemical cycles with respect to (236)U concentrations and (236)U/(239)Pu atom ratios in the Arctic and in ice cores.
137Cs, 239+240Pu concentrations and the 240Pu/239Pu atom ratio in a sediment core from the sub-aqueous delta of Yangtze River estuary
Publisher: Elsevier BV
Date: 10-2011
DOI: 10.1016/J.JENVRAD.2010.05.012
Abstract: A sediment core collected from the sub-aqueous delta of the Yangtze River estuary was subjected to analyses of (137)Cs and plutonium (Pu) isotopes. The (137)Cs was measured using γ-spectrometry at the laboratories at the Nanjing University and Pu isotopes were determined with Accelerator Mass Spectrometry (AMS), measurements made at the Australian National University. The results show considerable structure in the depth concentration profiles of the (137)Cs and (239+240)Pu. The shape of the vertical (137)Cs distribution in the sediment core was similar to that of the Pu. The maximum (137)Cs and (239+240)Pu concentrations were 16.21 ± 0.95 mBq/g and 0.716 ± 0.030 mBq/g, respectively, and appear at same depth. The average (240)Pu/(239)Pu atom ratio was 0.238 ± 0.007 in the sediment core, slightly higher than the average global fallout value. The changes in the (240)Pu/(239)Pu atom ratios in the sediment core indicate the presence of at least two different Pu sources, i.e., global fallout and another source, most likely close-in fallout from the Pacific Proving Grounds (PPG) in the Marshall Islands, and suggest the possibility that Pu isotopes are useful as a geochronological tool for coastal sediment studies. The (137)Cs and (239+240)Pu inventories were estimated to be 7100 ± 1200 Bq/m(2) and 407 ± 27 Bq/m(2), respectively. Approximately 40% of the (239+240)Pu inventory originated from the PPG close-in fallout and about 50% has derived from land-origin global fallout transported to the estuary by the river. This study confirms that AMS is a useful tool to measure (240)Pu/(239)Pu atom ratio and can provide valuable information on sedimentary processes in the coastal environment.
A comparison of fallout 236U and 239Pu uptake by Australian vegetation
Publisher: Elsevier BV
Date: 2016
DOI: 10.1016/J.JENVRAD.2015.06.021
Abstract: The isotopes (236)U and (239)Pu, both produced during nuclear weapons tests carried out in the 1950s and 1960s, are present in the environment and may be used as tracers for soil erosion studies. Although these radionuclides occur only at ultra-trace levels in nature, they can be readily measured by accelerator mass spectrometry with the 14UD heavy ion accelerator at the Australian National University. We have analysed a series of vegetation s les for their (236)U and (239)Pu concentration and compared the results with those found in the surrounding soil. (236)U could be measured in all collected s les whereas (239)Pu could not be detected in several vegetation s les due to its very low concentration, although it was readily detectable in the soil. We find that, relative to plutonium, (236)U is preferentially taken up by plants with enrichment factors ((236)U/(239)Pu)veg/((236)U/(239)Pu)soil that range between 7 and 52 in the present study.
A new fast-cycling system for AMS at ANU
Publisher: Elsevier BV
Date: 10-2015
236U and 239,240Pu ratios from soils around an Australian nuclear weapons test site
Publisher: Elsevier BV
Date: 2016
DOI: 10.1016/J.JENVRAD.2015.06.020
Abstract: The isotopes (236)U, (239)Pu and (240)Pu are present in surface soils as a result of global fallout from nuclear weapons tests carried out in the 1950's and 1960's. These isotopes potentially constitute artificial tracers of recent soil erosion and sediment movement. Only Accelerator Mass Spectrometry has the requisite sensitivity to measure all three isotopes at these environmental levels. Coupled with its relatively high throughput capabilities, this makes it feasible to conduct studies of erosion across the geographical extent of the Australian continent. In the Australian context, however, global fallout is not the only source of these isotopes. As part of its weapons development program the United Kingdom carried out a series of atmospheric and surface nuclear weapons tests at Maralinga, South Australia in 1956 and 1957. The tests have made a significant contribution to the Pu isotopic abundances present in the region around Maralinga and out to distances ∼1000 km, and impact on the assessment techniques used in the soil and sediment tracer studies. Quantification of the relative fallout contribution derived from detonations at Maralinga is complicated owing to significant contamination around the test site from numerous nuclear weapons safety trials that were also carried out around the site. We show that (236)U can provide new information on the component of the fallout that is derived from the local nuclear weapons tests, and highlight the potential of (236)U as a new fallout tracer.
Quality assurance in accelerator mass spectrometry: Results from an international round-robin exercise for 10Be
Publisher: Elsevier BV
Date: 10-2012
Element separation chemistry and cosmogenic 10Be dating of a ferromanganese crust
Publisher: Elsevier BV
Date: 11-2022
Scavenger hunt: Searching for the optimal target material for low-level 210Pb accelerator mass spectrometry
Publisher: Elsevier BV
Date: 10-2022
Actinides AMS at CIRCE and 236U and Pu measurements of structural and environmental samples from in and around a mothballed nuclear power plant
Publisher: Elsevier BV
Date: 2013
Development of 231Pa AMS measurements to improve radiological dose assessment from uranium mining and milling
Publisher: Elsevier BV
Date: 2019
Ultra-sensitive measurements of 36Cl and 236U at the Australian National University
Publisher: Elsevier BV
Date: 2013
A study of soil formation rates using10Be in the wet-dry tropics of northern Australia
Publisher: EDP Sciences
Date: 2012
26Al measurements with 10Be counting statistics
Publisher: Elsevier BV
Date: 06-2007
Manganese-53: Development of the AMS technique for exposure-age dating applications
Publisher: Elsevier BV
Date: 06-2007
Actinides, accelerators and erosion
Publisher: EDP Sciences
Date: 2012
Accelerator mass spectrometry measurements of 93Zr for astrophysical and nuclear technology applications
Publisher: Elsevier BV
Date: 09-2022
60Fe and244Pu deposited on Earth constrain the r-process yields of recent nearby supernovae
Publisher: American Association for the Advancement of Science (AAAS)
Date: 14-05-2021
Abstract: The rapid neutron capture process (r-process) produces many of the heavy chemical elements, but the astrophysical settings where it occurs remain unclear. Leading candidates are neutron star mergers and some types of supernovae. Wallner et al. analyzed the plutonium content of a deep-sea crust s le, identifying a few dozen atoms of the r-process isotope plutonium- 244 that were delivered to Earth within the past few million years. There was a simultaneous signal of iron-60, which is known to be produced in supernovae. Comparing the ratios of these isotopes constrains the relative contributions of supernovae and neutron star mergers to r-process nucleosynthesis. Science , this issue p. 742
Limits on Supernova-Associated
Fe
Publisher:
American Physical Society (APS)
Date:
27-11-2018
Publisher: American Physical Society (APS)
Date: 27-11-2018
Coulomb explosion of BeO− molecular ions – Revisited
Publisher: Elsevier BV
Date: 05-2023
Concentration and characterization of plutonium in soils of Hubei in central China
Publisher: Elsevier BV
Date: 2010
DOI: 10.1016/J.JENVRAD.2009.08.011
Abstract: To study the Pu concentration and isotope ratio distributions present in China, the (239+240)Pu total activities and (240)Pu/(239)Pu atom ratios in core soil s les from Hubei Province in central China were investigated using Accelerator Mass Spectrometry (AMS). The activities ranged from 0.019 to 0.502 mBqg(-1) and the (239+240)Pu inventories of 45 and approximately 55 Bqm(-2) agree well with that expected from global fallout. The (240)Pu/(239)Pu atom ratios in the soil ranged from 0.172 to 0.220. The ratios are similar to typical global fallout values. Hence, any close-in fallout contribution from the Chinese nuclear weapons tests, mainly conducted in the 1970s, must have either been negligible or had a similar (240)Pu/(239)Pu ratio to that of global fallout. The top 10 cm layer of the soil contributes approximately 90% of the total inventory and the maximum concentrations appeared in the 2-4 cm or 4-6 cm layers. It is suggested that climatic conditions and organic content are the two main factors that affect the vertical migration of plutonium in soil.
The potential of New Zealand kauri (Agathis australis) for testing the synchronicity of abrupt climate change during the Last Glacial Interval (60,000–11,700 years ago)
Publisher: Elsevier BV
Date: 12-2010
New and upgraded ionization chambers for AMS at the Australian National University
Publisher: Elsevier BV
Date: 2019
Recent near-Earth supernovae probed by global deposition of interstellar radioactive 60Fe
Publisher: Springer Science and Business Media LLC
Date: 06-04-2016
DOI: 10.1038/NATURE17196
A study of soil erosion rates using 239Pu, in the wet-dry tropics of northern Australia
Publisher: Elsevier BV
Date: 2020
DOI: 10.1016/J.JENVRAD.2019.106085
Abstract: The Daly River drains a large (52500 km
ColPuS, a new multi-isotope plutonium standard for Accelerator Mass Spectrometry
Publisher: Elsevier BV
Date: 2019
Uranium from German Nuclear Power Projects of the 1940s— A Nuclear Forensic Investigation
Publisher: Wiley
Date: 02-11-2015
A White Nile megalake during the last interglacial period
Publisher: Geological Society of America
Date: 02-2014
DOI: 10.1130/G35238.1
Plutonium isotope ratios in the Yenisey and Ob estuaries
Publisher: Elsevier BV
Date: 02-2004
Improving the detection limit for 182Hf
Publisher: Elsevier BV
Date: 06-2007
129I Dispersion in Argentina: Concentrations in Fresh and Marine Water and Deposition Fluences in Patagonia
Publisher: American Chemical Society (ACS)
Date: 23-08-2013
DOI: 10.1021/ES400610H
Abstract: Measurements of total iodine (I) and iodine-129 ((129)I) concentrations in rivers and lakes of Argentina are presented. Their latitudinal distribution can be explained by taking into account their main sources (oceanic emissions and biomass burning for I, and atmospheric nuclear tests for (129)I), transport mechanisms, and fallout patterns. From the measured (129)I concentrations in the studied lakes, deposition fluences for their catchment areas were estimated. These results agree with a model of the global deposition pattern due to the (129)I released by atmospheric nuclear weapon tests and with other fluences reported for the southern hemisphere. In addition, the first measurements of (129)I in shallow seawater from the South Atlantic Ocean are presented and discussed.
L-X-ray production cross-sections for PXAMS: Target and energy dependence for 50–200MeV hafnium ions
Publisher: Elsevier BV
Date: 06-2007
Nucleogenic 36Cl, 236U and 239Pu in uranium ores
Publisher: Elsevier BV
Date: 08-2008
Ultra-trace analysis of 36Cl by accelerator mass spectrometry: an interlaboratory study
Publisher: Springer Science and Business Media LLC
Date: 30-04-2011
DOI: 10.1007/S00216-011-4979-2
Abstract: A first international (36)Cl interlaboratory comparison has been initiated. Evaluation of the final results of the eight participating accelerator mass spectrometry (AMS) laboratories on three synthetic AgCl s les with (36)Cl/Cl ratios at the 10(-11), 10(-12), and 10(-13) level shows no difference in the sense of simple statistical significance. However, more detailed statistical analyses demonstrate certain interlaboratory bias and underestimation of uncertainties by some laboratories. Following subsequent remeasurement and reanalysis of the data from some AMS facilities, the round-robin data indicate that (36)Cl/Cl data from two in idual AMS laboratories can differ by up to 17%. Thus, the demand for further work on harmonising the (36)Cl-system on a worldwide scale and enlarging the improvement of measurements is obvious.
Injection optics for fast mass switching for accelerator mass spectrometry
Publisher: AIP
Date: 2013
DOI: 10.1063/1.4792817
14C-AMS as a tool for the investigation of mercury deposition at a remote Amazon location
Publisher: Elsevier BV
Date: 08-2004
Related Organisations
No related organisations have been discovered for Stephen Tims.
Related Funding Activities
Discovery Projects - Grant ID: DP130103548
Start Date: 04-2013
End Date: 12-2016
Amount: $360,000.00
Funder: Australian Research Council
View Funded ActivityDiscovery Projects - Grant ID: DP0986185
Start Date: 2009
End Date: 12-2012
Amount: $290,000.00
Funder: Australian Research Council
View Funded ActivityDiscovery Projects - Grant ID: DP0557122
Start Date: 2005
End Date: 12-2008
Amount: $150,000.00
Funder: Australian Research Council
View Funded ActivityARC Centres Of Excellence - Grant ID: CE200100008
Start Date: 08-2020
End Date: 08-2027
Amount: $35,000,000.00
Funder: Australian Research Council
View Funded ActivityDiscovery Projects - Grant ID: DP140100136
Start Date: 2014
End Date: 12-2017
Amount: $630,000.00
Funder: Australian Research Council
View Funded ActivityIndustrial Transformation Training Centres - Grant ID: IC230100036
Start Date: 2023
End Date: 12-2027
Amount: $4,999,600.00
Funder: Australian Research Council
View Funded Activity