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Feige J, Airo A, Berger D, Brückner D, Gärtner A, Genge M, Leya I, Habibi Marekani F, Hecht L, Klingner N, Lachner J, Li X, Merchel S, Nissen J, Patzer ABC, Peterson S, Schropp A, Sager C, Suttle MD, Trappitsch R, Weinhold J. Transport of dust across the Solar System: Constraints on the spatial origin of individual micrometeorites from cosmic-ray exposure. Philos Trans A Math Phys Eng Sci 2024; 382:20230197. [PMID: 38736334 DOI: 10.1098/rsta.2023.0197] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Accepted: 01/11/2024] [Indexed: 05/14/2024]
Abstract
The origin of micrometeorites (MMs) from asteroids and comets is well-established, but the relative contribution from these two classes remains poorly resolved. Likewise, determining the precise origin of individual MMs is an open challenge. Here, cosmic-ray exposure ages are used to resolve the spatial origins of 12 MMs collected from urban areas and Antarctica. Their 26Al and 10Be concentration, produced during cosmic-ray irradiation in space, were measured by accelerator mass spectrometry. These data are compared to results from a model simulating the transport and irradiation of the MM precursors in space. This model, for the first time, considers a variety of orbits, precursor particle sizes, compositions and densities and incorporates non-isotropic solar and galactic cosmic-ray flux profiles, depth-dependent production rates, as well as spherical evaporation during atmospheric entry. While the origin for six MMs remains ambiguous, two MMs show a preferential tendency towards an origin in the Inner Solar System (Near Earth Objects to the Asteroid Belt) and four towards an origin in the Outer Solar System (Jupiter Family Comets to the Kuiper Belt). These findings challenge the notion that dust originating from the Outer Solar System is unlikely to survive long-term transport and delivery to the terrestrial planets. This article is part of the theme issue 'Dust in the Solar System and beyond'.
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Affiliation(s)
- J Feige
- Department of Solar System, Impacts and Meteorites, Museum für Naturkunde, Leibniz-Institut für Evolutions- und Biodiversitätsforschung , Berlin 10115, Germany
- Zentrum für Astronomie und Astrophysik, Technische Universität Berlin , Berlin 10623, Germany
| | - A Airo
- Department of Solar System, Impacts and Meteorites, Museum für Naturkunde, Leibniz-Institut für Evolutions- und Biodiversitätsforschung , Berlin 10115, Germany
- Zentrum für Astronomie und Astrophysik, Technische Universität Berlin , Berlin 10623, Germany
| | - D Berger
- Center for Electron Microscopy (ZELMI), Technische Universität Berlin , Berlin 10623, Germany
| | - D Brückner
- Deutsches Elektronen-Synchrotron DESY , Hamburg 22607, Germany
| | - A Gärtner
- Senckenberg Naturhistorische Sammlungen Dresden, Museum für Mineralogie und Geologie, Sektion Mineralogie/Isotope Forensics , Dresden 01109, Germany
| | - M Genge
- Department of Earth Science and Engineering, Imperial College London , London SW7 2AZ, UK
| | - I Leya
- Space Science and Planetology, Physics Institute, University of Bern , Bern 3012, Switzerland
| | - F Habibi Marekani
- Zentrum für Astronomie und Astrophysik, Technische Universität Berlin , Berlin 10623, Germany
| | - L Hecht
- Department of Solar System, Impacts and Meteorites, Museum für Naturkunde, Leibniz-Institut für Evolutions- und Biodiversitätsforschung , Berlin 10115, Germany
| | - N Klingner
- Helmholtz-Zentrum Dresden-Rossendorf , Dresden 01328, Germany
| | - J Lachner
- Helmholtz-Zentrum Dresden-Rossendorf , Dresden 01328, Germany
- Faculty of Physics, Isotope Physics, University of Vienna , Vienna 1090, Austria
| | - X Li
- Forschungs-Neutronenquelle Heinz-Maier-Leibnitz FRM II, Technische Universität München , Garching 85748, Germany
| | - S Merchel
- Helmholtz-Zentrum Dresden-Rossendorf , Dresden 01328, Germany
- Faculty of Physics, Isotope Physics, University of Vienna , Vienna 1090, Austria
| | - J Nissen
- Center for Electron Microscopy (ZELMI), Technische Universität Berlin , Berlin 10623, Germany
| | - A B C Patzer
- Zentrum für Astronomie und Astrophysik, Technische Universität Berlin , Berlin 10623, Germany
| | - S Peterson
- Electron Microprobe Laboratory, University of Minnesota , Minneapolis, MN 55455-0153, USA
| | - A Schropp
- Center for X-ray and Nano Science CXNS, Deutsches Elektronen-Synchrotron DESY , Hamburg 22607, Germany
- Helmholtz Imaging, Deutsches Elektronen-Synchrotron DESY , Hamburg 22607, Germany
| | - C Sager
- Department of Solar System, Impacts and Meteorites, Museum für Naturkunde, Leibniz-Institut für Evolutions- und Biodiversitätsforschung , Berlin 10115, Germany
- Zentrum für Astronomie und Astrophysik, Technische Universität Berlin , Berlin 10623, Germany
| | - M D Suttle
- School of Physical Sciences, The Open University , Milton Keynes MK7 6AA, UK
- Dipartimento di Scienze della Terra, Università di Pisa , Pisa 56126, Italy
| | - R Trappitsch
- Laboratory for Biological Geochemistry, School of Architecture, Civil & Environmental Engineering, École Polytechnique Fédérale de Lausanne , Lausanne 1015, Switzerland
| | - J Weinhold
- Zentraleinrichtung 3D Technologien (ZE3D), Technische Universität Berlin , Berlin 10623, Germany
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Koll D, Faestermann T, Korschinek G, Leya I, Merchel S, Wallner A. The Dyadic Radionuclide System 60Fe / 53Mn to Distinguish Interstellar from Interplanetary 60Fe. EPJ Web Conf 2022. [DOI: 10.1051/epjconf/202226011022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The discovery of live 60Fe in a deep-sea crust with proposed interstellar origin followed by evidence for elevated interplanetary 3He in the same crust raised the question on how to unambiguously identify the true production site of the identified 60Fe. Here, we show the implementation of the dyadic radionuclide system 60Fe / 53Mn to serve as a tool for the identification of surplus interstellar 60Fe over interplanetary production. The recent updates in experimental 60Fe and 53Mn data from iron meteorites as well as in production rate models confirm the validity and robustness of this dyadic system for future applications.
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Merchel S, Braucher R, Lachner J, Rugel G. Which is the best 9Be carrier for 10Be/ 9Be accelerator mass spectrometry? MethodsX 2021; 8:101486. [PMID: 34434884 PMCID: PMC8374718 DOI: 10.1016/j.mex.2021.101486] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Accepted: 08/10/2021] [Indexed: 11/30/2022] Open
Abstract
Commercial 9Be solutions used for chemical preparation of samples for accelerator mass spectrometry contain the cosmogenic long-lived radionuclide 10Be at elevated but different 10Be/9Be levels. Within a systematic study of recently produced solutions, comparison to published data and new data on customised solutions from minerals, we recommend - if no customised solution is available - the 9Be solutions from Australian Chemical Reagents (ACR) or from LGC. They contain 10Be/9Be at the 3.4 × 10−15 level, which is still suitable for the majority of Earth science applications, compared to customised solutions at the 10−16 level for lowest-level studies. Commercial solutions from Scharlab having different lot numbers, i.e. an identification number assigned to a particular lot of material from a single manufacturer, vary in 10Be/9Be by up to a factor of nine. Hence, it seems an advisable strategy to buy a bigger quantity of a single production batch (such as 10 × 100 ml bottles of 9Be at 1 g l−1) and have them tested once at any AMS facility before first use.The best 9Be carrier for low-level 10Be/9Be applications is a customised one from minerals like phenakite. The best 9Be carriers for medium- and high-level 10Be/9Be applications are currently from Australian Chemical Reagents (ACR) or from LGC. As 9Be carriers from Scharlab of different batches (LOT) contain 10Be/9Be at different levels, it is advisable to buy a bigger number of bottles of the same LOT of commercial carriers after being identified to have reasonably low isotope ratios.
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Affiliation(s)
- Silke Merchel
- Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany.,Isotope Physics, University of Vienna, Austria
| | - Régis Braucher
- CEREGE, CNRS, Collège de France, IRD, INRAE, Aix Marseille Univ., Plateau de l'Arbois, Aix-en-Provence 13545, France
| | - Johannes Lachner
- Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany.,Isotope Physics, University of Vienna, Austria
| | - Georg Rugel
- Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany
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Wallner A, Feige J, Fifield LK, Froehlich MB, Golser R, Hotchkis MAC, Koll D, Leckenby G, Martschini M, Merchel S, Panjkov S, Pavetich S, Rugel G, Tims SG. 60Fe deposition during the late Pleistocene and the Holocene echoes past supernova activity. Proc Natl Acad Sci U S A 2020; 117:21873-21879. [PMID: 32839339 PMCID: PMC7486756 DOI: 10.1073/pnas.1916769117] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Nuclides synthesized in massive stars are ejected into space via stellar winds and supernova explosions. The solar system (SS) moves through the interstellar medium and collects these nucleosynthesis products. One such product is 60Fe, a radionuclide with a half-life of 2.6 My that is predominantly produced in massive stars and ejected in supernova explosions. Extraterrestrial 60Fe has been found on Earth, suggesting close-by supernova explosions ∼2 to 3 and ∼6 Ma. Here, we report on the detection of a continuous interstellar 60Fe influx on Earth over the past ∼33,000 y. This time period coincides with passage of our SS through such interstellar clouds, which have a significantly larger particle density compared to the local average interstellar medium embedding our SS for the past few million years. The interstellar 60Fe was extracted from five deep-sea sediment samples and accelerator mass spectrometry was used for single-atom counting. The low number of 19 detected atoms indicates a continued but low influx of interstellar 60Fe. The measured 60Fe time profile over the 33 ky, obtained with a time resolution of about ±9 ky, does not seem to reflect any large changes in the interstellar particle density during Earth's passage through local interstellar clouds, which could be expected if the local cloud represented an isolated remnant of the most recent supernova ejecta that traversed the Earth ∼2 to 3 Ma. The identified 60Fe influx may signal a late echo of some million-year-old supernovae with the 60Fe-bearing dust particles still permeating the interstellar medium.
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Affiliation(s)
- A Wallner
- Department of Nuclear Physics, Research School of Physics, Australian National University, Canberra, ACT 2601, Australia;
- Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, 01328 Dresden, Germany
| | - J Feige
- Isotope Physics, Faculty of Physics, Vienna Environmental Research Accelerator Laboratory, University of Vienna, 1090 Vienna, Austria
- Zentrum für Astronomie und Astrophysik, Technische Universität Berlin, 10623 Berlin, Germany
| | - L K Fifield
- Department of Nuclear Physics, Research School of Physics, Australian National University, Canberra, ACT 2601, Australia
| | - M B Froehlich
- Department of Nuclear Physics, Research School of Physics, Australian National University, Canberra, ACT 2601, Australia
| | - R Golser
- Isotope Physics, Faculty of Physics, Vienna Environmental Research Accelerator Laboratory, University of Vienna, 1090 Vienna, Austria
| | - M A C Hotchkis
- Centre for Accelerator Science, Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW 2234, Australia
| | - D Koll
- Department of Nuclear Physics, Research School of Physics, Australian National University, Canberra, ACT 2601, Australia
| | - G Leckenby
- Department of Nuclear Physics, Research School of Physics, Australian National University, Canberra, ACT 2601, Australia
| | - M Martschini
- Department of Nuclear Physics, Research School of Physics, Australian National University, Canberra, ACT 2601, Australia
- Isotope Physics, Faculty of Physics, Vienna Environmental Research Accelerator Laboratory, University of Vienna, 1090 Vienna, Austria
| | - S Merchel
- Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, 01328 Dresden, Germany
| | - S Panjkov
- Department of Nuclear Physics, Research School of Physics, Australian National University, Canberra, ACT 2601, Australia
| | - S Pavetich
- Department of Nuclear Physics, Research School of Physics, Australian National University, Canberra, ACT 2601, Australia
| | - G Rugel
- Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, 01328 Dresden, Germany
| | - S G Tims
- Department of Nuclear Physics, Research School of Physics, Australian National University, Canberra, ACT 2601, Australia
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Martschini M, Lachner J, Merchel S, Priller A, Steier P, Wallner A, Wieser A, Golser R. The quest for AMS of 182Hf – why poor gas gives pure beams. EPJ Web Conf 2020. [DOI: 10.1051/epjconf/202023202003] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
The long-lived radioisotope 182Hf (T1/2 = 8.9 Ma) is of high astrophysical interest as its potential abundance in environmental archives would provide insight into recent r-process nucleosynthesis in the vicinity of our solar system. Despite substantial efforts, it could not be measured at natural abundances with conventional AMS so far due to strong isobaric interference from stable 182W. Equally important is an increase in ion source efficiency for the anions of interest.
The new Ion Laser InterAction Mass Spectrometry (ILIAMS) technique at VERA tackles the problem of elemental selectivity in AMS with a novel approach. It achieves near-complete suppression of isobar contaminants via selective laser photodetachment of decelerated anion beams in a gas-filled radio-frequency quadrupole (RFQ) ion cooler. The technique exploits differences in electron affinities (EA) within elemental or molecular isobaric systems neutralizing anions with EAs smaller than the photon energy. Alternatively, these differences in EA can also facilitate anion separation via chemical reactions with the buffer gas.
We present first results with this approach on AMS-detection of 182Hf. With He +O2 mixtures as buffer gas in the RFQ, suppression of 182WF5− vs 180HfF 5− by >105 has been demonstrated. Mass analysis of the ejected anion beam identified the formation of oxyfluorides as an important reaction channel. The overall Hf-detection efficiency at VERA presently is 1.4% and the W-corrected blank value is 182Hf/180Hf = (3.4 ± 2.1)×10−14. In addition, a survey of different sample materials for highest negative ion yields of HfF 5− with Cs-sputtering has been conducted.
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Slavkovská Z, Wallner A, Reifarth R, Pavetich S, Bott L, Brückner B, Göbel K, Al-Khasawneh K, Koll D, Merchel S, Reich M, Volknandt M, Weigand M. Investigation of 54Fe(n,γ) 55Fe and 35Cl(n, γ) 36Cl reaction cross sections at keV energies by Accelerator Mass Spectrometry. EPJ Web Conf 2020. [DOI: 10.1051/epjconf/202023202005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Activations with neutrons in the keV energy range were routinely performed at the Karlsruhe Institute of Technology (KIT) in Germany in order to simulate stellar conditions for neutron-capture cross sections. A quasi-Maxwell-Boltzmann neutron spectrum of kT = 25 keV, being of interest for the astrophysical s-process, was produced by the 7Li(p,n) reaction utilizing a 1912 keV proton beam at the Karlsruhe Van de Graaff accelerator. Activated samples resulting in long-lived nuclear reaction products with half-lives in the order of yr 100 Myr were analyzed by Accelerator Mass Spectrometry (AMS). Comparison of the obtained reaction cross sections to literature data from previous Time-of-Flight (ToF) measurements showed that the selected AMS data are systematically lower than the ToF data. To investigate this discrepancy, 54Fe(n,γ)55Fe and 35Cl(n,γ)36Cl reaction cross sections were newly measured at the Frankfurt Neutron Source (FRANZ) in Germany. To complement the existing data, an additional neutron activation of 54Fe and 35Cl at a proton energy of 2 MeV was performed. The results will give implications for the stellar environment at kT = 90 keV, reaching the not yet experimentally explored high-energy s-process range. AMS measurements of the activated samples are scheduled.
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Koll D, Korschinek G, Faestermann T, Gómez-Guzmán JM, Kipfstuhl S, Merchel S, Welch JM. Interstellar ^{60}Fe in Antarctica. Phys Rev Lett 2019; 123:072701. [PMID: 31491090 DOI: 10.1103/physrevlett.123.072701] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2019] [Revised: 05/23/2019] [Indexed: 06/10/2023]
Abstract
Earth is constantly bombarded with extraterrestrial dust containing invaluable information about extraterrestrial processes, such as structure formation by stellar explosions or nucleosynthesis, which could be traced back by long-lived radionuclides. Here, we report the very first detection of a recent ^{60}Fe influx onto Earth by analyzing 500 kg of snow from Antarctica by accelerator mass spectrometry. By the measurement of the cosmogenically produced radionuclide ^{53}Mn, an atomic ratio of ^{60}Fe/^{53}Mn=0.017 was found, significantly above cosmogenic production. After elimination of possible terrestrial sources, such as global fallout, the excess of ^{60}Fe could only be attributed to interstellar ^{60}Fe which might originate from the solar neighborhood.
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Affiliation(s)
- Dominik Koll
- Physik-Department, Technische Universität München, 85748 Garching, Germany
| | - Gunther Korschinek
- Physik-Department, Technische Universität München, 85748 Garching, Germany
- Excellence Cluster Universe, 85748 Garching, Germany
| | - Thomas Faestermann
- Physik-Department, Technische Universität München, 85748 Garching, Germany
- Excellence Cluster Universe, 85748 Garching, Germany
| | - J M Gómez-Guzmán
- Physik-Department, Technische Universität München, 85748 Garching, Germany
| | - Sepp Kipfstuhl
- Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung, 27568 Bremerhaven, Germany
| | - Silke Merchel
- Helmholtz-Zentrum Dresden-Rossendorf, 01328 Dresden, Germany
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Feige J, Wallner A, Altmeyer R, Fifield LK, Golser R, Merchel S, Rugel G, Steier P, Tims SG, Winkler SR. Limits on Supernova-Associated ^{60}Fe/^{26}Al Nucleosynthesis Ratios from Accelerator Mass Spectrometry Measurements of Deep-Sea Sediments. Phys Rev Lett 2018; 121:221103. [PMID: 30547642 DOI: 10.1103/physrevlett.121.221103] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Revised: 09/20/2018] [Indexed: 06/09/2023]
Abstract
We searched for the presence of ^{26}Al in deep-sea sediments as a signature of supernova influx. Our data show an exponential dependence of ^{26}Al with the sample age that is fully compatible with radioactive decay of terrigenic ^{26}Al. The same set of samples demonstrated a clear supernova ^{60}Fe signal between 1.7 and 3.2 Myr ago. Combining our ^{26}Al data with the recently reported ^{60}Fe data results in a lower limit of 0.18_{-0.08}^{+0.15} for the local interstellar ^{60}Fe/^{26}Al isotope ratio. It compares to most of the ratios deduced from nucleosynthesis models and is within the range of the observed average galactic ^{60}Fe/^{26}Al flux ratio of (0.15±0.05).
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Affiliation(s)
- Jenny Feige
- Technische Universität Berlin, Department of Astronomy and Astrophysics, Hardenbergstr. 36, 10623 Berlin, Germany
- University of Vienna, Faculty of Physics-Isotope Research and Nuclear Physics, VERA Laboratory, Währingerstr. 17, 1090 Vienna, Austria
| | - Anton Wallner
- The Australian National University, Department of Nuclear Physics, Canberra ACT 2601, Australia
| | - Randolf Altmeyer
- Humboldt-Universität zu Berlin, Department of Mathematics, Unter den Linden 6, 10099 Berlin, Germany
| | - L Keith Fifield
- The Australian National University, Department of Nuclear Physics, Canberra ACT 2601, Australia
| | - Robin Golser
- University of Vienna, Faculty of Physics-Isotope Research and Nuclear Physics, VERA Laboratory, Währingerstr. 17, 1090 Vienna, Austria
| | - Silke Merchel
- Helmholtz-Zentrum Dresden-Rossendorf, Helmholtz Institute Freiberg for Resource Technology, Bautzner Landstr. 400, 01328 Dresden, Germany
| | - Georg Rugel
- Helmholtz-Zentrum Dresden-Rossendorf, Helmholtz Institute Freiberg for Resource Technology, Bautzner Landstr. 400, 01328 Dresden, Germany
| | - Peter Steier
- University of Vienna, Faculty of Physics-Isotope Research and Nuclear Physics, VERA Laboratory, Währingerstr. 17, 1090 Vienna, Austria
| | - Stephen G Tims
- The Australian National University, Department of Nuclear Physics, Canberra ACT 2601, Australia
| | - Stephan R Winkler
- University of Vienna, Faculty of Physics-Isotope Research and Nuclear Physics, VERA Laboratory, Währingerstr. 17, 1090 Vienna, Austria
- iThemba LABS-Laboratory for Accelerator Based Science, Somerset West 7129, South Africa
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Sulaymonova VA, Fuchs MC, Gloaguen R, Möckel R, Merchel S, Rudolph M, Krbetschek MR. Feldspar flotation as a quartz-purification method in cosmogenic nuclide dating: A case study of fluvial sediments from the Pamir. MethodsX 2018; 5:717-726. [PMID: 30094201 PMCID: PMC6070659 DOI: 10.1016/j.mex.2018.06.014] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2018] [Accepted: 06/26/2018] [Indexed: 11/16/2022] Open
Abstract
Our flotation cell is built of borosilicate glass, holds up to 90 g of sample, and achieves quartz and feldspar separation in ≤2 h. The procedure uses air bubbles to which the feldspars attach, 0.2% HF to reduce the surface energy of quartz, dodecylamine solution as a feldspar collector, and operates at a pH range of 2.4–2.7 at room temperature. We trace the stepwise enrichment of quartz by X-ray diffraction analysis, which shows that froth flotation is the decisive step to reach 95–100% purity from the initial 23–46%.
Cosmogenic nuclide (CN) dating relies on specific target minerals such as quartz as markers to identify geologic events, including the timing of landscape evolution. The presence of feldspar in sediment samples poses a challenge to the separation of quartz and affects the chemical procedures for extracting the radioactive CNs 10Be and 26Al. Additionally, feldspar contamination reduces the 26Al/27Al ratio, thus hinders the accurate determination of 26Al by accelerator mass spectrometry (AMS). Using fluvial sediment samples from Central Asia, which contain 16–50 weight percent (wt.%) of feldspar, we show that the standard physical separation and chemical cleaning-up procedures for quartz-enrichment reduces the feldspar content to only 9–47 wt.%. We present a new froth flotation mineral-separation device and procedure that allows for very effective quartz enrichment before CN chemistry. Our flotation cell, which has a volume of 600 cm3, is built of borosilicate glass, holds up to 90 g of sample, and achieves quartz and feldspar separation in ≤2 h for very feldspar-rich samples. We trace the stepwise enrichment of quartz to 95–100% purity with our procedure by X-ray diffraction analysis.
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Affiliation(s)
- Vasila A. Sulaymonova
- Geologie, TU Bergakademie Freiberg, Germany
- University of Central Asia, Kyrgyzstan
- Corresponding author at: Geologie, TU Bergakademie Freiberg, Bernhard-von-Cotta-Str. 2, 09599, Freiberg, Germany.
| | - Margret C. Fuchs
- Applied Physics, TU Bergakademie Freiberg, Germany
- Helmholtz-Zentrum Dresden-Rossendorf, Helmholtz Institute Freiberg for Resource Technology, Germany
| | - Richard Gloaguen
- Helmholtz-Zentrum Dresden-Rossendorf, Helmholtz Institute Freiberg for Resource Technology, Germany
| | - Robert Möckel
- Helmholtz-Zentrum Dresden-Rossendorf, Helmholtz Institute Freiberg for Resource Technology, Germany
| | - Silke Merchel
- Helmholtz-Zentrum Dresden-Rossendorf, Helmholtz Institute Freiberg for Resource Technology, Germany
| | - Martin Rudolph
- Helmholtz-Zentrum Dresden-Rossendorf, Helmholtz Institute Freiberg for Resource Technology, Germany
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Schwanghart W, Bernhardt A, Stolle A, Hoelzmann P, Adhikari BR, Andermann C, Tofelde S, Merchel S, Rugel G, Fort M, Korup O. Repeated catastrophic valley infill following medieval earthquakes in the Nepal Himalaya. Science 2016; 351:147-50. [DOI: 10.1126/science.aac9865] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2015] [Accepted: 11/25/2015] [Indexed: 11/02/2022]
Affiliation(s)
- Wolfgang Schwanghart
- Institute of Earth and Environmental Science, University of Potsdam, Potsdam, Germany
| | - Anne Bernhardt
- Institute of Earth and Environmental Science, University of Potsdam, Potsdam, Germany
| | - Amelie Stolle
- Institute of Earth and Environmental Science, University of Potsdam, Potsdam, Germany
| | - Philipp Hoelzmann
- Institute of Geographical Sciences, Freie Universität Berlin, Berlin, Germany
| | | | | | - Stefanie Tofelde
- Institute of Earth and Environmental Science, University of Potsdam, Potsdam, Germany
| | - Silke Merchel
- Helmholtz-Zentrum Dresden-Rossendorf, Helmholtz Institute Freiberg for Resource Technology, Dresden, Germany
| | - Georg Rugel
- Helmholtz-Zentrum Dresden-Rossendorf, Helmholtz Institute Freiberg for Resource Technology, Dresden, Germany
| | - Monique Fort
- CNRS UMR 8586 Prodig, Département de Géographie, Université Paris-Diderot-SPC, Paris, France
| | - Oliver Korup
- Institute of Earth and Environmental Science, University of Potsdam, Potsdam, Germany
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Schwehr KA, Otosaka S, Merchel S, Kaplan DI, Zhang S, Xu C, Li HP, Ho YF, Yeager CM, Santschi PH. Speciation of iodine isotopes inside and outside of a contaminant plume at the Savannah River Site. Sci Total Environ 2014; 497-498:671-678. [PMID: 25173764 DOI: 10.1016/j.scitotenv.2014.07.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2013] [Revised: 06/30/2014] [Accepted: 07/01/2014] [Indexed: 06/03/2023]
Abstract
A primary obstacle in understanding the fate and transport of the toxic radionuclide (129)I (a thyroid seeker) is an accurate method to distinguish it from the stable isotope, (127)I, and to quantify the various species at environmentally relevant concentrations (~10(-8) M). A pH-dependent solvent extraction and combustion method was paired with accelerator mass spectrometry (AMS) to measure ambient levels of (129)I/(127)I isotope ratios and iodine speciation (iodide (I(-)), iodate (IO3(-)), and organo-I (OI)) in aquatic systems. The method exhibited an overall uncertainty of 10% or less for I(-) and IO3(-), and less than 30% for OI species concentrations and enabled (129)I measurements as low as 0.001 Bq/L (1 Bq/L=10(-13) M). The method was used to analyze groundwater from the Savannah River Site (SRS), South Carolina, USA, along a pH, redox potential (Eh), and organic carbon gradient (8-60 μM DOC). The data confirmed that the (129)I/(127)I ratios and species distribution were strongly pH dependent and varied in a systematic manner from the strongly acidic source. While (129)I speciation in plume samples containing total I concentrations >1.7 Bq/L was similar whether measured by AMS or GC-MS ([I(-)]≫[IO3(-)]=[OI]), AMS enabled (129)I speciation measurements at much lower concentrations than what was possible with GC-MS. AMS analyses demonstrated that groundwater samples minimally impacted by the plume were still orders of magnitude higher than ambient (129)I concentrations typically found elsewhere in the USA groundwaters and rivers. This is likely due to past atmospheric releases of volatile (129)I species by SRS nuclear reprocessing facilities near the study site. Furthermore, the results confirmed the existence of (129)I not only as I(-), but also as OI and IO3(-) species.
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Affiliation(s)
- Kathleen A Schwehr
- Laboratory for Oceanographic and Environmental Research, Department of Marine Sciences, Texas A&M University, OCSB 3029, 200 Seawolf Parkway, Galveston, TX 77553, United States
| | - Shigeyoshi Otosaka
- Laboratory for Oceanographic and Environmental Research, Department of Marine Sciences, Texas A&M University, OCSB 3029, 200 Seawolf Parkway, Galveston, TX 77553, United States; Research Group for Environmental Science, Japan Atomic Energy Agency, Tokai Mura, Ibaraki 319 1195, Japan
| | - Silke Merchel
- Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstraße 400, 01328 Dresden, Germany
| | - Daniel I Kaplan
- Savannah River National Laboratory, Aiken, SC 29808, United States
| | - Saijin Zhang
- Laboratory for Oceanographic and Environmental Research, Department of Marine Sciences, Texas A&M University, OCSB 3029, 200 Seawolf Parkway, Galveston, TX 77553, United States
| | - Chen Xu
- Laboratory for Oceanographic and Environmental Research, Department of Marine Sciences, Texas A&M University, OCSB 3029, 200 Seawolf Parkway, Galveston, TX 77553, United States
| | - Hsiu-Ping Li
- Laboratory for Oceanographic and Environmental Research, Department of Marine Sciences, Texas A&M University, OCSB 3029, 200 Seawolf Parkway, Galveston, TX 77553, United States
| | - Yi-Fang Ho
- Laboratory for Oceanographic and Environmental Research, Department of Marine Sciences, Texas A&M University, OCSB 3029, 200 Seawolf Parkway, Galveston, TX 77553, United States
| | - Chris M Yeager
- Los Alamos National Laboratory, Los Alamos, NM 87545, United States
| | - Peter H Santschi
- Laboratory for Oceanographic and Environmental Research, Department of Marine Sciences, Texas A&M University, OCSB 3029, 200 Seawolf Parkway, Galveston, TX 77553, United States
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Feige J, Wallner A, Fifield L, Korschinek G, Merchel S, Rugel G, Steier P, Winkler S, Golser R. AMS measurements of cosmogenic and supernova-ejected radionuclides in deep-sea sediment cores. EPJ Web of Conferences 2013. [DOI: 10.1051/epjconf/20136303003] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Wallner A, Melber K, Merchel S, Ott U, Forstner O, Golser R, Kutschera W, Priller A, Steier P. Stable platinum isotope measurements in presolar nanodiamonds by TEAMS. Nucl Instrum Methods Phys Res B 2013; 294:496-502. [PMID: 23565017 PMCID: PMC3617595 DOI: 10.1016/j.nimb.2012.03.036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/21/2011] [Revised: 03/17/2012] [Indexed: 06/02/2023]
Abstract
Nanodiamonds are stardust grains commonly found in primitive meteorites. They survived the formation of the solar system and kept their own individuality. Measurements of trace-element isotopic signatures in these grains will help understanding heavy element nucleosynthesis in massive stars and dust formation from their ejecta. We have continued previous attempts to search for stable Pt isotope anomalies in nanodiamonds via trace element accelerator mass spectrometry (TEAMS). The installation of a new injector beam line at the VERA facility allowed studying low traces of stable elements in different materials. Moreover, recent experiments showed that VERA provides the required measurement precision together with a low Pt machine background. Here, we observed for the first time an indication for enhancements of 198Pt/195Pt isotope ratios in two diamond residues prepared by different chemical separation techniques from the Allende meteorite. Variations in other isotopic ratios were within analytical uncertainty, and no anomaly was identified in a third diamond fraction.
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Affiliation(s)
- A. Wallner
- University of Vienna, Faculty of Physics, VERA Laboratory, Währinger Strasse 17, A-1090 Vienna, Austria
- Department of Nuclear Physics, Research School of Physics and Engineering, The Australian National University, Canberra, Australia
- Australian Nuclear Science and Technology Organisation (ANSTO), Lucas Heights, Australia
| | - K. Melber
- University of Vienna, Faculty of Physics, VERA Laboratory, Währinger Strasse 17, A-1090 Vienna, Austria
| | - S. Merchel
- Helmholtz-Zentrum Dresden-Rossendorf (HZDR), D-01314 Dresden, Germany
| | - U. Ott
- Max-Planck-Institut für Chemie, Joh.-J.-Becherweg 27, D-55128 Mainz, Germany
| | - O. Forstner
- University of Vienna, Faculty of Physics, VERA Laboratory, Währinger Strasse 17, A-1090 Vienna, Austria
| | - R. Golser
- University of Vienna, Faculty of Physics, VERA Laboratory, Währinger Strasse 17, A-1090 Vienna, Austria
| | - W. Kutschera
- University of Vienna, Faculty of Physics, VERA Laboratory, Währinger Strasse 17, A-1090 Vienna, Austria
| | - A. Priller
- University of Vienna, Faculty of Physics, VERA Laboratory, Währinger Strasse 17, A-1090 Vienna, Austria
| | - P. Steier
- University of Vienna, Faculty of Physics, VERA Laboratory, Währinger Strasse 17, A-1090 Vienna, Austria
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Hampe D, Gleisberg B, Akhmadaliev S, Rugel G, Merchel S. Determination of 41Ca with LSC and AMS: method development, modifications and applications. J Radioanal Nucl Chem 2012. [DOI: 10.1007/s10967-012-2145-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Altinsoy ME, Merchel S. Electrotactile Feedback for Handheld Devices with Touch Screen and Simulation of Roughness. IEEE Trans Haptics 2012; 5:6-13. [PMID: 26963824 DOI: 10.1109/toh.2011.56] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
We present a novel electrotactile display that can be integrated into current handheld devices with touch screens. In this display, tactile information is presented to the fingertip of the user by transmitting small currents through electrodes. Experiments were conducted to investigate the perception of simulated textures using this electrotactile display technique. One fundamental feature of texture, which is the focus of this study, is roughness. The aim of the first experiment was to investigate the relationship between electrotactile stimulation parameters such as current and pulse frequency and the perception of roughness. An increase in the current magnitude resulted in an increase in perceived roughness. The aim of the second experiment was to investigate parameter combinations of electrotactile stimuli can be used to simulate textures. Subjects adjusted the intensity and frequency of the current stimuli until the simulated textures were perceived as being equal to reference textures such as sandpapers of varying grit numbers and grooved woods with varying groove widths. Subjects tended to find an electrotactile stimulus with a high current magnitude and a low pulse frequency more suitable to represent rough surfaces. They tended to find just-perceptible current magnitudes suitable for very smooth surfaces and did not show a preference for any frequency.
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Steinhauser G, Merchel S, Knappik R. Nuclear analytical methods: We've got the hammer for your nail. Appl Radiat Isot 2011; 69:1585. [DOI: 10.1016/j.apradiso.2011.05.027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2011] [Revised: 05/20/2011] [Accepted: 05/20/2011] [Indexed: 11/16/2022]
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Merchel S, Berger A. Determination of nitrogen in boron carbide by instrumental photon activation analysis. Anal Bioanal Chem 2007; 388:385-9. [PMID: 17342535 DOI: 10.1007/s00216-007-1217-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2007] [Revised: 02/13/2007] [Accepted: 02/16/2007] [Indexed: 10/23/2022]
Abstract
Boron carbide is widely used as industrial material, because of its extreme hardness, and as a neutron absorber. As part of a round-robin exercise leading to certification of a new reference material (ERM-ED102) which was demanded by the industry we analysed nitrogen in boron carbide by inert gas fusion analysis (GFA) and instrumental photon activation analysis (IPAA) using the 14N(gamma,n)13N nuclear reaction. The latter approach is the only non-destructive method among all the methods applied. By using photons with energy below the threshold of the 12C(gamma,n)11C reaction, we hindered activation of matrix and other impurities. A recently installed beam with a very low lateral activating flux gradient enabled us to homogeneously activate sample masses of approximately 1 g. Taking extra precautions, i.e. self-absorption correction and deconvolution of the complex decay curves, we calculated a nitrogen concentration of 2260+/-100 microg g-1, which is in good agreement with our GFA value of 2303+/-64 microg g-1. The values are the second and third highest of a rather atypical (non-S-shape) distribution of data of 14 round-robin participants. It is of utmost importance for the certification process that our IPAA value is the only one not produced by inert gas fusion analysis and, therefore, the only one which is not affected by a possible incomplete release of nitrogen from high-melting boron carbide.
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Affiliation(s)
- Silke Merchel
- Federal Institute for Materials Research and Testing (BAM), 12200, Berlin, Germany.
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Merchel S, Herpers U. An Update on Radiochemical Separation Techniques for the Determination of Long-Lived Radionuclides via Accelerator Mass Spectrometry. RADIOCHIM ACTA 1999. [DOI: 10.1524/ract.1999.84.4.215] [Citation(s) in RCA: 140] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Affiliation(s)
- S. Merchel
- Abteilung Nuklearchemie, Universität zu Köln, D-50674 Köln, Germany
| | - U. Herpers
- Abteilung Nuklearchemie, Universität zu Köln, D-50674 Köln, Germany
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Fenyvesi A, Merchel S, Takàcs S, Szelecsenyis F, Tärkänyi F, Qaim SM. Excitation Functions of natNe(3He,x)22,24Na and natNe(α,x)22,24Na Processes: Investigation of Production of ^^Na and ^Na at a Medium-Sized Cyclotron. RADIOCHIM ACTA 1997. [DOI: 10.1524/ract.1997.79.4.207] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Affiliation(s)
- A. Fenyvesi
- Institute of Nuclear Research of the Hungarian Academy of Sciences, P.O. Box 51, H-4001 Debrecen, Hungary
| | - S. Merchel
- Institut für Nuklearchemie, Forschungszentrum Jülich GmbH, D-52425 Jülich, Germany
| | - S. Takàcs
- Institute of Nuclear Research of the Hungarian Academy of Sciences, P.O. Box 51, H-4001 Debrecen, Hungary
| | - F. Szelecsenyis
- Institute of Nuclear Research of the Hungarian Academy of Sciences, P.O. Box 51, H-4001 Debrecen, Hungary
| | - F. Tärkänyi
- Institute of Nuclear Research of the Hungarian Academy of Sciences, P.O. Box 51, H-4001 Debrecen, Hungary
| | - S. M. Qaim
- Institut für Nuklearchemie, Forschungszentrum Jülich GmbH, D-52425 Jülich, Germany
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