Fakultät für Physik Stefan-Meyer-Institut Isotopenphysik für subatomare Physik E I N L A D U N G zum gemeinsamen V E R A – S M I – S E M I N A R von Ani APRAHAMIAN A. Alikhanyan National Laboratory of Armenia and Institute of Structure & Nuclear Astrophysics University of Notre Dame, Notre Dame, Indiana, USA High Precision Mass Measurements of Nuclei and the Neutron Star Merger The US science academies report on “Connecting Quarks to the Cosmos'' identified eleven of the most challenging open questions for all of physics in the 21st century. One of these eleven questions included the identification of the site(s) for the production of the heaviest elements found in nature: How were elements Fe to U made? Most of the elements above Fe in the periodic table are thought to have been produced by either the slow (s-process) or rapid (r-process) capture of neutrons in astrophysical environments. The s-process proceeds close to stability and astrophysical sites have been identified, while the r-process allows the production of nuclei much further from stability and potential sites remain mostly unresolved. The recent observation of gravitational waves from two neutron star mergers simultaneously with the spectroscopy indicated that rare earth elements were made in this so-called kilonova event. The questions remain, are there enough such mergers? Are mergers the only source of r-process elements ? This seminar will address the role of nuclear physics measurements, specifically the high precision measurement of nuclear masses and their role in understanding this potential site for the synthesis of the elements from Fe to U. Donnerstag, 06. Juni 2019, 16:30 Uhr 1090 Wien, Währinger Str. 17, "Kavalierstrakt", 1. Stock, Victor-Franz-Hess Hörsaal W. Kutschera E.Widmann E.M. Wild Fakultät für Physik Isotopenphysik E I N L A D U N G zum V E R A - S E M I N A R von Oana Gâza and Tiberiu Sava Horia Hulubei – National Institute for Physics and Nuclear Engineering, Bucharest, Romania Research at the Centre for Accelerator Mass Spectrometry (AMS) in Bucharest The AMS center in Bucharest was founded in 2013, relying on a High Voltage 1 MV Tandetron particle accelerator and the associated sample preparation laboratory. With this multi-isotopic AMS machine the routinely analyzed species are 14C, 10Be, 26Al and 129I, while recently different tests were performed to determine isotopic ratios in actinide species (239,240,242Pu, 236U). Radiocarbon remains the isotope with the largest share within our measurements, enabling studies in archaeology, environment and cultural heritage. A niche position in our radiocarbon analysis is represented by the dating of single amino- acids resulting from the separation of collagen extracted from potentially risky bone material using a High Pressure Liquid Chromatography (HPLC) method. Beside the radiocarbon applications we present also some research examples of using isotopic ratios of 10Be/9Be, 26Al/27Al and 129I/127I for paleo-reconstruction of glaciers and oceanography, respectively. Donnerstag, 24. Januar 2019, 16:30 Uhr 1090 Wien, Währinger Str. 17, "Kavalierstrakt", 1. Stock, Victor-Franz-Hess Hörsaal W. Kutschera E.M. Wild Fakultät für Physik Isotopenphysik E I N L A D U N G zum V E R A - S E M I N A R von Manfred GRÖNING Terrestrial Environment Laboratory International Atomic Energy Agency, Vienna, Austria New definition of the kilogram and the international δ-scales for stable isotope measurements In November 2018, it was decided to change the definition of the kilogram as basis for the international (SI-unit) from use of the „Kilogram Prototype“ stored in Paris, to a new definition based on constants of nature. Such a change is not yet possible for other scales, like for those defining isotope ratio measurements used in many scientific areas. Variations of isotope ratios of elements provide insight in many processes, whether of geologic, biogenic, industrial or environmental nature. The necessary high precision for those measurements is achieved by direct comparison of samples with established international reference materials, in so called δ-scale measurements. While the concept is well proven and applied now for over 30 elements, it depends on the long-term availability of the scale defining reference materials. At the IAEA, scale defining materials for hydrogen, carbon, oxygen and sulphur are preserved and distributed. This presentation will discuss the situation to maintain these δ-scales, compare it with the case of the kilogram, and will provide examples of challenges and solutions to preserve scales over long time periods for worldwide consistency of measurements. Donnerstag, 17. Januar 2019, 16:30 Uhr 1090 Wien, Währinger Str. 17, "Kavalierstrakt", 1. Stock, Victor-Franz-Hess Hörsaal W. Kutschera E.M. Wild Fakultät für Physik Isotopenphysik E I N L A D U N G zum V E R A - S E M I N A R von Karin Hain Faculty of Physics, Isotope Physics, University of Vienna, Austria Study of the global distribution of the long-lived radionuclide Tc-99 with AMS 5 The long-lived fission product Technetium-99 (t1/2 = 2.1·10 a) has been released into the environment by reprocessing plants and as global fallout by nuclear weapons tests (around 140 TBq). The meta-stable 99mTc is increasingly used as medical tracer leading to an additional accumulation of its decay product 99Tc as waste. Due to the expected mobility and its long half-life, 99Tc is not only a radionuclide of primary concern for nuclear waste storage, but is also considered a potential oceanographic tracer. Whereas the liquid 99Tc emissions from the reprocessing plants are rather well studied, there is hardly any data on the global distribution of 99Tc in environmental reservoirs affected by nuclear weapons fallout. We recently started a FWF funded project to improve this situation by pursuing two different approaches for the detection of 99Tc: A large accelerator system in combination with a gas-filled magnet system, available at the Technical University of Munich, and the Ion-Laser-InterAction-Mass-Spectrometry (ILIAMS) setup at VERA. The AMS setup in Munich, which has already shown sufficient suppression of the stable isobar 99Ru, is currently being applied to analyse environmental 99Tc concentrations e.g. in Pacific Ocean water and a peat bog. First results on the detected 99Tc concentrations and suitable chemical procedures for the extraction of Tc will be presented after an overview of previous studies on the Tc distribution in the environment and the general research questions of the present project. Donnerstag, 13. Juni 2019, 16:30 Uhr 1090 Wien, Währinger Str. 17, "Kavalierstrakt", 1. Stock, Victor-Franz-Hess Hörsaal W. Kutschera E.M. Wild Fakultät für Physik Isotopenphysik E I N L A D U N G zum V E R A - S E M I N A R von Irka HAJDAS Laboratory of Ion Beam Physics, ETH Zurich 14C dating potentials for interdisciplinary collaborations in the protection of cultural heritage and the detection of forgeries During the last seven decades, radiocarbon dating revolutionized chronologies of archeological and environmental records. Radiocarbon dating of cultural heritage objects, although applied from the early days on, was only sporadically presented and published. Recent developments in the AMS technique expanded the field of applications by allowing almost non-destructive sampling of precious objects. Moreover, new material types such as binding media, mortar or iron can be analyzed allowing for studies of a wide range of objects for research as well as for detection of forgeries. However, as the success in applications of the method to the detection of forgeries created a great interest within the trade of antiquities, the radiocarbon community is searching for a critical approach that will prevent analysis of looted antique objects. The last but not least problem that requires attention is the diminishing level of atmospheric 14C, caused by the combustion of fossil carbon which will soon reduce the 14C excess from the above-ground nuclear weapons testing period to below the pre-bomb level, with consequences for 14C dating [1]. [1] Heather D. Graven, Impact of fossil fuel emissions on atmospheric radiocarbon and various applications of radiocarbon over this century, PNAS 112 (2015) 9542. Donnerstag, 27. Juni 2019, 16:30 Uhr 1090 Wien, Währinger Str. 17, "Kavalierstrakt", 1. Stock, Victor-Franz-Hess Hörsaal W. Kutschera E.M. Wild Fakultät für Physik Isotopenphysik E I N L A D U N G zum V E R A - S E M I N A R von Maki HONDA Graduate School of Pure and Applied Sciences, University of Tsukuba, Japan The study of radioactive iodine from the Fukushima accident 131 129 A large amount of the radioactive iodine isotopes I (t1/2 = 8.01 d) and I (t1/2 = 1.57×107 y) were released into the environment during the Fukushima Dai-ichi nuclear power plant (FDNPP) accident on March 2011. Radioactive iodine is one of the key fission products to be monitored due to the tendency of accumulation in the thyroid gland. There is an ethical obligation of science to serve society, and to help Japanese to better understand what happened, how it happened and why, even though public trust in science was lost in the aftermath of the accident. The study of radioactive iodine from the accident can fulfill this obligation. Information of environmental radiation monitoring was required in the initial phase of the FDNPP accident in making rational assessment of the radiological consequences to the public. However, in reality, it was not available at that time since monitoring system did not function due to the loss of power supply. Part of the on-site release characteristics and transportation mechanisms have been estimated via long-lived 129I in environmental samples.