Browsing by Author "Smith, AM"
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- Item10Be concentrations in snow at Law Dome, Antarctica following the 29 October 20 and 20 January 2005 solar cosmic ray events(World Scientific, 2009-08) Pedro, JB; Smith, AM; Duldig, ML; Klekociuk, AR; Simon, KJ; Curran, MAJ; van Ommen, TD; Fink, D; Morgan, VI; Galton-Fenzi, BKRecent model calculations have attempted to quantify the contribution of major energetic solar cosmic ray (SCR) events to 10Be production.1,2 In this study we compare modeled 10Be production by SCR events to measured 10Be concentrations in a Law Dome snow pit record. The snow pit record spans 2.7 years, providing a quasi-monthly 10Be sampling resolution which overlaps with the SCR events of 29 Oct 2003 and 20 Jan 2005. These events were calculated to increase monthly 10Be production in the polar atmosphere (>65° S geomagnetic latitude) by ~60% and ~120% above the GCR background, respectively2. A strong peak in 10Be concentrations (>4σ above the 2.7 y mean value) was observed ~1 month after the 20 Jan 2005 event. By contrast, no signal in 10Be concentrations was observed following the weaker 29 Oct 2003 series of events. The concentration of 10Be in ice core records involves interplay between production, transport, and deposition processes. We used a particle dispersion model to assess vertical and meridional transport of aerosols from the lower stratosphere where SCR production of 10Be is expected to occur, to the troposphere from where deposition to the ice sheet occurs. Model results suggested that a coherent SCR production signal could be transported to the troposphere within weeks to months following both SCR events. We argue that only the 20 Jan 2005 SCR event was observed in measured concentrations due to favorable atmospheric transport, relatively high production yield compared to the 29 Oct 2003 event, and a relatively high level of precipitation in the Law Dome region in the month following the event. This result encourages further examination of SCR signals in 10Be ice core data. © 2009 World Scientific Publishing
- Item10Be in last deglacial climate simulated by ECHAM5-HAM – Part I: climatological influences on 10Be deposition(Copernicus Publications, 2013-11-25) Heikkilä, UE; Phipps, SJ; Smith, AMReconstruction of solar irradiance has only been possible for the Holocene so far. During the last deglaciation, two solar proxies (10Be and 14C) deviate strongly, both of them being influenced by climatic changes in a different way. This work addresses the climate influence on 10Be deposition by means of ECHAM5-HAM atmospheric aerosol–climate model simulations, forced by sea surface temperatures and sea ice extent created by the CSIRO Mk3L coupled climate system model. Three time slice simulations were performed during the last deglaciation: 10 000 BP ("10k"), 11 000 BP ("11k") and 12 000 BP ("12k"), each 30 yr long. The same, theoretical, 10Be production rate was used in each simulation to isolate the impact of climate on 10Be deposition. The changes are found to follow roughly the reduction in the greenhouse gas concentrations within the simulations. The 10k and 11k simulations produce a surface cooling which is symmetrically amplified in the 12k simulation. The precipitation rate is only slightly reduced at high latitudes, but there is a northward shift in the polar jet in the Northern Hemisphere, and the stratospheric westerly winds are significantly weakened. These changes occur where the sea ice change is largest in the deglaciation simulations. This leads to a longer residence time of 10Be in the stratosphere by 30 (10k and 11k) to 80 (12k) days, increasing the atmospheric concentrations (25–30% in 10k and 11k and 100% in 12k). Furthermore the shift of westerlies in the troposphere leads to an increase of tropospheric 10Be concentrations, especially at high latitudes. The contribution of dry deposition generally increases, but decreases where sea ice changes are largest. In total, the 10Be deposition rate changes by no more than 20% at mid- to high latitudes, but by up to 50% in the tropics. We conclude that on "long" time scales (a year to a few years), climatic influences on 10Be deposition remain small (less than 50%) even though atmospheric concentrations can vary significantly. Averaged over a longer period, all 10Be produced has to be deposited by mass conservation. This dominates over any climatic influences on 10Be deposition. Snow concentrations, however, do not follow mass conservation and can potentially be impacted more by climate due to precipitation changes. Quantifying the impact of deglacial climate modulation on 10Be in terms of preserving the solar signal locally is analysed in an accompanying paper (Heikkilä et al., 10Be in late deglacial climate simulated by ECHAM5-HAM – Part 2: Isolating the solar signal from 10Be deposition). © Author(s) 2013.
- Item10Be in late deglacial climate simulated by ECHAM5-HAM – Part 2: Isolating the solar signal from 10Be deposition(Copernicus Publications, 2014-04-01) Heikkilä, UE; Shi, X; Phipps, SJ; Smith, AMThis study investigates the effect of deglacial climate on the deposition of the solar proxy 10Be globally, and at two specific locations, the GRIP site at Summit, Central Greenland, and the Law Dome site in coastal Antarctica. The deglacial climate is represented by three 30 year time slice simulations of 10 000 BP (years before present = 1950 CE), 11 000 and 12 000 BP, compared with a preindustrial control simulation. The model used is the ECHAM5-HAM atmospheric aerosol–climate model, driven with sea-surface temperatures and sea ice cover simulated using the CSIRO Mk3L coupled climate system model. The focus is on isolating the 10Be production signal, driven by solar variability, from the weather- or climate-driven noise in the 10Be deposition flux during different stages of climate. The production signal varies at lower frequencies, dominated by the 11 year solar cycle within the 30 year timescale of these experiments. The climatic noise is of higher frequencies than 11 years during the 30 year period studied. We first apply empirical orthogonal function (EOF) analysis to global 10Be deposition on the annual scale and find that the first principal component, consisting of the spatial pattern of mean 10Be deposition and the temporally varying solar signal, explains 64% of the variability. The following principal components are closely related to those of precipitation. Then, we apply ensemble empirical decomposition (EEMD) analysis to the time series of 10Be deposition at GRIP and at Law Dome, which is an effective method for adaptively decomposing the time series into different frequency components. The low-frequency components and the long-term trend represent production and have reduced noise compared to the entire frequency spectrum of the deposition. The high-frequency components represent climate-driven noise related to the seasonal cycle of e.g. precipitation and are closely connected to high frequencies of precipitation. These results firstly show that the 10Be atmospheric production signal is preserved in the deposition flux to surface even during climates very different from today's both in global data and at two specific locations. Secondly, noise can be effectively reduced from 10Be deposition data by simply applying the EOF analysis in the case of a reasonably large number of available data sets, or by decomposing the individual data sets to filter out high-frequency fluctuations. © Author(s) 2014.
- Item14-CO in glacial ice from Law Dome, Antarctica as a tracer of changes in atmospheric OH abundance from 1870 AD to present(Australian Nuclear Science and Technology Organisation, 2021-11-15) Smith, AM; Neff, PD; Petrenko, VV; Etheridge, DM; Crosier, EM; Hmiel, B; Thornton, DP; Jong, LM; Beaudette, R; Harth, CM; Langenfelds, RL; Mitrevski, B; Curran, MAJ; Buizert, C; Murray, LT; Trudinger, CM; Dyonisius, MN; Ng, J; Severinghaus, JP; Weiss, RFHydroxyl, OH, is the main tropospheric oxidant and determines the lifetime of methane and most other trace gases in the atmosphere, thereby controlling the amount of greenhouse warming produced by these gases. Changes in OH concentration ([OH]) in response to large changes in reactive trace gas emissions (which may occur in the future) are uncertain. Measurements of 14C containing carbon monoxide (14CO) and other tracers such as methyl chloroform over the last ≈25 years have been successfully used to monitor changes in average [OH], but there are no observational constraints on [OH] further back in time. Reconstructions of 14CO from ice cores could in principle provide such constraints but are complicated by in-situ production of 14CO by cosmic rays directly in the ice. Recent work in Antarctica and Greenland shows that this in-situ component would be relatively small and can be accurately corrected for at sites with very high snow accumulation rates. A joint US and Australian team sampled and measured firn air and ice at Law Dome, Antarctica (2018-19 season, site DE08-OH, 1.2 m a-1 ice-equivalent snow accumulation), to a maximum depth of 240 m. Trapped air was extracted from the ice using an onsite large-volume ice melting system. Preliminary comparisons of methane measured in the samples to existing ice core records and atmospheric measurements suggest ice core air sample ages spanning from the 1870s to the early 2000s. Firn-air samples from the snow surface to 81 m depth capture air from the early 2000s to present. Analyses of [CO] and halocarbons in the samples show a relatively low and stable procedural CO blank and demonstrate that the samples are unaffected by ambient air inclusion. 14CO analyses in these firn and ice core air samples have been successfully completed. Corrections for in-situ 14CO production, validated against direct atmospheric measurements for the more recent samples, have allowed us to develop a preliminary 14CO history. This history will be interpreted with the aid of the GEOS-Chem chemistry-transport model to place the first observational constraints on the variability of Southern Hemisphere [OH] since ≈1870 AD. © The Authors
- Item14C AMS measurements of the bomb pulse in N- and S- hemisphere tropical trees(Elsevier, 1997-03-02) Murphy, JO; Lawson, EM; Fink, D; Hotchkis, MAC; Hua, Q; Jacobsen, GE; Smith, AM; Tuniz, CThe 14C bomb-pulse signature has been measured by AMS on cross-dateable teak samples from N- and S-hemisphere locations in the tropics. Excellent agreement is found with the atmospheric 14C content in the period 1955 to 1980 for the respective hemispheres. These results demonstrate that 14C measurements can be used to facilitate growth rate determinations in tropical trees. © 1997 Elsevier B.V.
- Item14C analyses at the ANTARES AMS Centre: dating the log coffins of northwest Thailand(Elsevier, 1994-06-03) Hotchkis, MAC; Fink, D; Jacobsen, GE; Lawson, EM; Shying, ME; Smith, AM; Tuniz, C; Barbetti, M; Grave, P; Quan, HM; Head, JRecent results of 14C analyses at the ANTARES AMS Centre are presented. Test measurements of 14C blanks demonstrate an ultimate sensitivity of the order of 10−15 (14C/12C ratio). Measurements of unknowns have been made with a precision in the range 1–1.5% using a “slow cycling” mode of operation where the injection magnet field is changed to inject 14C and 13C alternately. Results are presented for a series of log coffins from cave burials in NW Thailand. © 1994 Elsevier B.V.
- Item14C in uranium and thorium minerals: a signature of cluster radioactivity?(Springer Nature, 1999-06-01) Bonetti, R; Guglielmetti, A; Poli, G; Sacchi, E; Fink, D; Hotchkis, MAC; Jacobsen, GE; Lawson, EM; Hua, Q; Smith, AM; Tuniz, CVarious uranium and thorium minerals have been analysed with accelerator mass spectrometry to determine their 14C content. It is found that, whenever the contribution from secondary reactions such as the 11B(α,p)14C is sufficiently low, the 14C concentration is consistent with that expected from 14C (spontaneous) cluster radioactivity from radium isotopes of the uranium and thorium natural series. © Springer-Verlag 1999
- Item14CH4 measurements in Greenland ice: investigating last glacial termination CH4 sources(American Association for the Advancement of Science (AAAS), 2009-04-24) Petrenko, VV; Smith, AM; Brook, EJ; Lowe, DC; Riedel, K; Brailsford, G; Hua, Q; Schaefer, H; Reeh, N; Weiss, RF; Etheridge, DM; Severinghaus, JPThe cause of a large increase of atmospheric methane concentration during the Younger Dryas-Preboreal abrupt climatic transition (~11,600 years ago) has been the subject of much debate. The carbon-14 (14C) content of methane (14CH4) should distinguish between wetland and clathrate contributions to this increase. We present measurements of 14CH4 in glacial ice, targeting this transition, performed by using ice samples obtained from an ablation site in west Greenland. Measured 14CH4 values were higher than predicted under any scenario. Sample 14CH4 appears to be elevated by direct cosmogenic 14C production in ice. 14C of CO was measured to better understand this process and correct the sample 14CH4. Corrected results suggest that wetland sources were likely responsible for the majority of the Younger Dryas-Preboreal CH4 rise. © 2009, American Association for the Advancement of Science (AAAS)
- ItemThe 14CO2 bomb pulse in firn air at Aurora Basin, East Antarctica(Australian Partnerships in Ice Core Sciences (APICS) Workshop, 2016-03-07) Thornton, DP; Etheridge, DM; Trudinger, CM; Rubino, M; Smith, AM; Curran, MAJ; Vance, TR; Chappellaz, JThe 14C isotope of CO2 produced in the atmosphere by nuclear weapons testing in the 1960’s is incorporated in air in open pores of firn before close-off in bubbles in Antarctic ice. The rapid growth and subsequent decline provides a unique test for the smoothing of atmospheric CO2 signals due to firn diffusion and bubble close off, and the level of smoothing quantifies the time resolution with which trace gas histories can be reconstructed from ice cores. The presence of a ‘bomb pulse’ in the record also permits accurate dating of CO2 and other gases in air. Aurora Basin North (ABN) will contribute new and valuable 2000-year atmospheric records from this data sparse region of inland East Antarctica. ABN has an annual snow accumulation up to 150 kgm-2 year-1, a low mean annual temperature and high elevation. Firn air samples were collected from ABN during December 2013 in stainless-steel canisters and cylinders and 0.5L glass flasks, from varying depths covering the whole firn column at the ABN site. Extraction of CO2 from ABN samples has been performed at the CSIRO ICELAB and transferred to ANSTO to derive the 14C activity of CO2 in ABN firn air. As expected, results suggest the age spread at ABN is wider than sites with higher accumulation, such as Law Dome. Firn modelling is also planned and the 14C results will be used as inputs for the modelling to help determine (with other gas measurements) the age and age spread of air in firn and ice at ABN.
- Item15th International Conference on Accelerator Mass Spectrometry(Australian Nuclear Science and Technology Organisation, 2021-11-15) Bertuch, F; Child, DP; Fink, D; Fülöp, RH; Hotchkis, MAC; Hua, Q; Jacobsen, GE; Jenkinson, A; Levchenko, VA; Simon, KJ; Smith, AM; Wilcken, KM; Williams, AA; Williams, ML; Yang, B; Fallon, SJ; Wallner, TOn behalf of the AMS-15 Organising committee, we would like to thank you for attending the 15th International Conference on Accelerator Mass Spectrometry. Held as an online event for the first time, the 2021 conference attracted over 300 attendees with presentations delivered by colleagues and professionals from around the globe.Applications of AMS to the world’s most pressing problems/questions: A-1 : Earth’s dynamic climate palaeoclimate studies, human impacts on climate, data for climate modelling. A-2 : Water resource sustainability groundwater dating, hydrology, water quality and management A-3 : Living landscapes soil production, carbon storage, erosion, sediment transport, geomorphology. A-4 : Catastrophic natural events volcanoes, cyclones, earthquakes, tsunamis, space weather, mass extinctions. A-5 : Advancing human health metabolic and bio-kinetic studies, bomb-pulse dating, diagnostics and bio-tracing. A-6 : Challenges of the nuclear age nuclear safeguards, nuclear forensics, nuclear waste management, nuclear site monitoring, impacts of nuclear accidents. A-7 :Understanding the human story archaeology, human evolution and migration, history, art and cultural heritage A-8 : Understanding the cosmos fundamental physics, nuclear astrophysics, nuclear physics AMS Research and Development: T-1 : Novel AMS systems, components and techniques T-2 : Suppression of isobars and other interferences T-3 : Ion sourcery T-4 : New AMS isotopes T-5 : Advances in sample preparation T-6 : Data quality and management T-7 : Facility Reports (Poster Presentation only)
- Item20 year Australian Antarctic strategic plan(Australian Government Department of the Environment and Energy, 2014-07) Williams, AG; Chambers, SD; Smith, AM
- Item7Be and 10Be concentrations in recent firn and ice at Law Dome, Antarctica(Elsevier, 2000-10-01) Smith, AM; Fink, D; Child, DP; Levchenko, VA; Morgan, VI; Curran, MAJ; Etheridge, DM; Elliott, GOver the past three years, the Australian National Tandem for Applied Research (ANTARES) AMS facility at ANSTO has been expanding its sample preparation and measurement capability, particularly for 10Be, 26Al and 36Cl. During this time, ANSTO has continued its collaboration with the AAD and CSIRO Atmospheric Research on the measurement of cosmogenic isotopes from Law Dome, Antarctica. This research program has been supported by the construction of a dedicated geochemistry laboratory for the processing of ice and rock samples for the preparation of AMS targets. Here we present our first results for 10Be concentrations measured in ice cores from three sites at Law Dome and describe the sample processing protocol and aspects of the AMS measurement procedure. These sites are characterised by an eightfold difference in accumulation rate with a common precipitation source. In combination with an established ice chronology, this has enabled some preliminary findings concerning the relationship between the snow accumulation rate and the measured 10Be concentration for Law Dome during recent times. Additionally, we present 7Be and 10Be/7Be measurements made for a few surface snow samples from Law Dome and Australia. © 2000 Elsevier Science B.V.
- ItemAccelerator mass spectrometry: revealing subtle signals in ice sheets(Past Global Changes, 2013-02-13) Smith, AMAccelerator Mass Spectrometry (AMS) determines the ratio of a rare isotope, normally radioactive and of intermediate half-life, to a stable isotope. AMS permits the detection of individual atoms in a sample and so is an inherently sensitive analytical technique. A well-known example is radiocarbon dating (14C, t1/2 = 5730 a), where measurement of the 14C/12C ratio permits determination of the age of an artifact. Such AMS measurements can be performed rapidly (~ 20 min), at good precision (~ 0.3 ‰), with high sensitivity (< 10-15) and on very small samples (as little a few μg of carbon). Radiometric measurements, by contrast, require much larger sample masses and much longer measurement times in order to obtain good precision. Besides its use as a chronometer, 14C is increasingly used as a tracer in geophysical studies as the amount of carbon required for a measurement has decreased.At ANSTO we routinely measure 14C, 10Be, 26Al and the Actinides by AMS and in 2010 we added 7Be to the list. Here I give some examples from the ice sheets in Greenland and Antarctica of palaeoclimate research I have been involved in. In each case AMS has provided the unique key to unlock these important climate archives. I will discuss 14C studies of atmospheric gases from firn air and ice core bubbles, with the objective of learning more about the natural and anthropogenic sources of the important greenhouse gas methane. Additionally, I will discuss studies of the beryllium isotopes, 7Be (t1/2 = 53 d) and 10Be (t1/2 = 1.4 _ 106 a) in snow and ice, with the objective of improving the use of 10Be as a proxy for Solar variability.
- ItemAMS at ANTARES – the first 10 years(Elsevier, 2000-10) Lawson, EM; Elliott, G; Fallon, J; Fink, D; Hotchkis, MAC; Hua, Q; Jacobsen, GE; Lee, P; Smith, AM; Tuniz, C; Zoppi, UThe status and capabilities of the ANTARES AMS facility after 10 years are reviewed. The common AMS radioisotopes, 10Be, 14C, 26A1, 36C1 and 129I, are routinely analysed. A capability for the detection of 236U and other actinide isotopes has been developed. The measurement program includes support to Quaternary science projects at Australian universities and to ANSTO projects in global climate change and nuclear safeguards. © 2000 Elsevier Science B.V.
- ItemAMS dating of ancient plant residues from experimental stone tools: a pilot study(Elsevier, 2014-09) Yates, AB; Smith, AM; Parr, J; Scheffers, AM; Joannes-Boyau, RResidue analyses on stone artefacts have contributed to resolving functional questions in stone tool research. Although identifying the function of tools through the analysis of their micro-residues is possible, the establishment of a sound numerical chronology for stone tools lacking a clear stratigraphic sequence, such as surface scatters, remains a challenge. While radiocarbon dating of blood residue on stone artefacts has been published previously (Loy 1987, 1990, 1993; Loy et al., 1990; Nelson et al.1986), this paper reports on an experiment designed to assess the possibility of directly dating residues on stone artefacts by accelerator mass spectrometry (AMS) based radiocarbon measurements. Innovative with this approach is (1) the use of mid and late Holocene pre-dated plant material (wood and peat), processed with contemporarily manufactured stone flakes under controlled laboratory conditions and (2) the use of very small carbon masses (less than 22 μg) for radiocarbon dating. The 14C results of the wood residues are in excellent agreement with the original sample, whereas the 14C results of the peat residues yield a wider age variation as expected due to the inhomogeneity of the material, but nevertheless, provided dates within an expected age range. Preliminary results demonstrate the feasibility of dating very small amounts of plant residue on lithics directly when contaminants are confined.© 2013, Elsevier Ltd.
- ItemAMS radiocarbon analysis of microsamples(Australian Institute of Nuclear Science and Engineering, Australian Nuclear Science & Technology Organisation and Australian Museum, 1997-02-12) Jacobsen, GE; Hua, Q; Tarshishi, J; Fink, D; Hotchkis, MAC; Lawson, EM; Smith, AM; Tuniz, CThe ANTARES AMS Centre has two chemistry laboratories dedicated to preparing targets for measurement. Target preparation encompasses a variety of activities ranging from the curation of incoming samples to the numerous steps involved in the purification and processing of dissimilar samples. One of the two laboratories is set up for the physical and chemical pretreatment of 14C samples. Treatments include cleaning by sonification, sorting, grinding and sieving, and chemical treatments such as the standard AAA treatment, and solvent extraction. Combustion and graphitisation are also carried out in this laboratory. The second laboratory is a clean room and is dedicated to the combustion, hydrolysis and graphitisation of 14C samples as well as processing targets for the other isotopes. Combustion is achieved by heating the sample to 900 deg C in the presence of CuO, the resulting gas is purified by passing over Ag and Cu wire at 600 deg C. Graphitisation is carried out by reducing the CO{sub 2} with an iron catalyst (600 deg C) in the presence of zinc (400 deg C) and a small amount of hydrogen. Samples such as charcoal, shell, bone, wood, sediment, seawater and groundwater, containing 0.3-1 mg or more of original carbon, are processed routinely for radiocarbon analysis. The current 14C chemistry background for 1 mg carbon is approx. 0.3 percent of modern carbon (pMC) enabling materials` dating up to 45 000 BP.
- ItemThe ANSTO isotope cycling system(Cambridge University Press, 2016-02-09) Watt, GC; Boronkay, S; Smith, AM; Hotchkis, MACA number of electronic systems are used on the ANTARES accelerator at ANSTO to implement its fast cycling accelerator mass spectrometry (AMS) capability. The fast cycling system was originally installed and commissioned in 1993 and has recently been updated. This paper describes the more significant of the electronic systems, such as the controller ("sequencer"), the high-voltage power supply ("bouncer"), the fast electrostatic beam chopper, and those used for measurement of the pulsed ion beam current. The sequencer, a programmable 15-bit digital pulse generator, generates the timing and sequencing of the control signals for bouncing voltage selection, beam chopping, Faraday cup current measurement, and rare isotope event measurement. The new sequencer is implemented using a National Instruments FPGA (field programmable gate array) card, programmed using LabVIEW 2010. This device has the benefits of host CPU-independent operation, simple interfacing (PCI), a small footprint, off-the-shelf availability at modest cost, and ease of functionality upgrade. The sequencer provides 15 synchronous digital signals, whose "on" and "off" transitions can be independently specified, in both number and time, with a time resolution of between 0.5 and 128 μs, and with the total duration between repetitions adjustable between 65.5 ms and 8.4 s per cycle. It is hosted by a generic PC because of the low-cost and ubiquity of these. The stand-alone FPGA-based approach ensures that the sequencer determinism is unaffected by processes executing in the host CPU. © 2013 Arizona Board of Regents on behalf of the University of Arizona
- ItemThe ANSTO – University of Wollongong in-situ 14C extraction laboratory(Elsevier, 2019-01-01) Fülöp, RH; Fink, D; Yang, B; Codilean, AY; Smith, AM; Wacker, L; Levchenko, VA; Dunai, TJWe present our first 14C in-situ results for calibration and system blanks from the recently completed Australian Nuclear Science and Technology Organisation (ANSTO) – University of Wollongong (UOW) in-situ 14C extraction system. System performance parameters and quality is evidenced by low 14C blanks and good reproducibility for multiple targets from different reference materials. The 14C extraction scheme exploits the high temperature phase transformation of quartz to cristobalite in order to quantitatively extract the carbon as CO2. The in-situ 14C extraction system comprises three independently operated and modular units that are used for initial in-vacuo removal of meteoric 14C, followed by offline high-temperature heating of quartz to release trapped cosmogenic in-situ 14C, and finally CO2 gas purification and mass measurement. The design allows for rapid sample throughput of about 6 samples per week with samples masses ranging between 0.5 and 4 g of clean quartz. Other features include single-pass catalytic oxidation using mixed copper (I,II) oxide as catalyst, use of UHV-compatible components and of vacuum annealed copper tubing. We present results for sets of purified quartz samples prepared from CRONUS-A, CRONUS-R and CRONUS-N inter-comparison materials, with final averages consistent with published values. Following extraction and cleaning, CO2 gas aliquots for some of the samples were analysed using the ETH Zürich CO2 gas ion source at the ETH MICADAS AMS facility in addition to CO2 being graphitised using the ANSTO laser-heated graphitisation micro-furnace and then analysed on ANSTO’s ANTARES AMS facility. System blanks using either CO2 or graphite ion-sources at both facilities are on the order of ∼1 × 104 atoms. © 2018 Elsevier B.V.
- ItemANSTO's radioactive waste management policy: preliminary environmental review(Australian Nuclear Science and Technology Organisation, 1996-05) Levins, DM; Airey, PL; Breadner, B; Bull, PS; Camilleri, A; Dimitrovski, L; Gorman, T; Harries, JR; Innes, RW; Jarquin, E; Jay, G; Ridal, A; Smith, AMFor over forty years radioactive wastes have been generated by ANSTO (and its predecessor the AAEC) from the operation of nuclear facilities the production of radioisotopes for medical and industrial use and from various research activities. The quantities and activities of radioactive waste currently at Lucas Heights are very small compared to many other nuclear facilities overseas especially those in countries with nuclear power program. Nevertheless in the absence of a repository for nuclear wastes in Australia and guidelines for waste conditioning the waste inventory has been growing steadily. This report reviews the status of radioactive waste management at ANSTO including spent fuel management treatment of effluents and environmental monitoring. It gives details of: relevant legislative regulatory and related requirements; sources and types of radioactive waste generated at ANSTO; waste quantities and activities (both cumulative and annual arisings); existing practices and procedures for waste management and environmental monitoring; recommended broad strategies for dealing with radioactive waste management issues. Detailed proposals on how the recommendations should be implemented is the subject of a companion internal document the Radioactive Waste Management Action Plan 1996-2000 which provides details of the tasks to be undertaken milestones and resource requirements.
- ItemThe ANTARES AMS Centre : a status report(Cambridge University Press, 2016-07-18) Tuniz, C; Fink, D; Hotchkis, MAC; Jacobsen, GE; Lawson, EM; Smith, AM; Hua, Q; Drewer, P; Lee, P; Levchenko, VA; Bird, R; Boldeman, JW; Barbetti, M; Taylor, G; Head, JThe ANTARES accelerator mass spectrometry facility at Lucas Heights Research Laboratory is operational and AMS measurements of 14C, 26Al and 36Cl are being carried out routinely. Measurement of 129I recently commenced and capabilities for other long-lived radioisotopes such as 10Be are being established. The overall aim of the facility is to develop advanced programs in Quaternary science, global climate change, biomedicine and nuclear safeguards. © the Department of Geosciences, The University of Arizona