[Todos] [SEMINARIOS] SEMINARIO GCIA.INV.Y APL-TANDAR 26/JUNIO/15 10:30 hs - DR. ANTON WALLNER 244PU AND 60FE ON EARTH - ARE THERE SIGNATURES OF RECENT SUPERNOVAE ?

[Graciela Mastrogiacomo]

>***************************************************************************
>                            SEMINARIOS 2015
>   Gerencia Investigación y Aplicaciones - TANDAR - CNEA
>****************************************************************************
>
>Viernes 26 de junio, 10:30 Hs.
>Auditorio Emma Pérez Ferreira - Edificio TANDAR
>
>
>                        Dr. Anton WALLNER (*)
>Department of Nuclear Physics, Research School of
>                   Physics and Engineering
>            The Australian National University
>
>244Pu and 60Fe on Earth – are there signatures
>                of recent supernovae?
>
>SUMMARY
>Accelerator mass spectrometry (AMS) represents a
>sensitive technique for studying long-lived radionuclides
>through ultra-low isotope ratio measurements. In this
>talk I will highlight applications related to nuclear astrophysics:
>
>Direct observation and detection of freshly synthesized
>material from space is a powerful tool for understanding
>nucleosynthesis. Here I will report on the detection of
>live interstellar radionuclides trapped in terrestrial archives.
>“How were the heavy elements from iron to uranium made?”
>It is clear that half of these elements including all actinides
>are made in a process requiring high neutron densities
>(r-process). Their sites and history, however, still remain
>unclear. Candidates are supernova (SN) explosions or
>neutron-star mergers, the latter at least 100 times less
>frequent than SN. New data using AMS suggest an
>unexpected low abundance of interstellar 244Pu (t1/2=81 Myr).
>Another isotope produced in SNe is 60Fe (t1/2=2.6 Myr).
>A previous measurement at TU Munich of an Ocean
>crust-sample showed an enhanced 60Fe signal of possibly
>extraterrestrial origin - a close-by SN about 2-3 Myr ago?
>We have started a similar program at the ANU resulting in
>an exceptional sensitivity for 60Fe detection. I will discuss
>a new approach to determine 60Fe’s disputed half-life value.
>In addition, we have analyzed several deep-sea sediments,
>crusts and nodules for extraterrestrial 60Fe. I will present
>new data and will relate them to potential exposure of
>Earth to recent SNe
>__________________________________________________
>
>(*) El Dr. Wallner es doctor de la Universidad de Viena,
>posdoc de la Universidad Técnica de Munich y actualmente
>es profesor de la Universidad Nacional de Australia. Su campo
>de investigación comprende la medición de datos nucleares
>fundamentales para reactores de fusión y fisión nuclear,
>estudio experimental de nucleosíntesis estelar y busqueda
>de rastros de explosiones supernovas en la Tierra.
>
>Web:
>http://physics.anu.edu.au/people/profile.php?ID=1201&tab=available_projects
>__________________________________________________
>
>Quedan todos cordialmente invitados !!!
>
>10:15 hs  Cafe
>10:30 hs  Inicio de Seminario
>
>Auditorio Emma Pérez Ferreira - Edificio TANDAR
>CNEA - Centro Atómico Constituyentes
>Av. Gral. Paz 1499 (y Constituyentes)
>6772-7065 / 7174 / 7531
>
>Coordinadores:
>Dra. Ana Gabriela Grunfeld: < mailto: grunfeld en tandar.cnea.gov.ar >
>Dr. Horacio R. Corti: hrcorti en cnea.gov.ar
>
>Secretaria:
>Graciela Mastrogiacomo: < mailto: gmastro en tandar.cnea.gov.ar >
>
>http://www.tandar.cnea.gov.ar/eventos/seminariosGIyA
>
>
>
>
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