Heidelberg 2015 – wissenschaftliches Programm
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A: Fachverband Atomphysik
A 1: Precision spectroscopy of atoms and ions I (with Q)
A 1.6: Vortrag
Montag, 23. März 2015, 12:45–13:00, C/HSW
Spectroscopy of the hyperfine structure splitting and isotopic shift on 97−99Technetium — •Tobias Kron1, Michael Franzmann1, Jose-Luis Henares2, Sebastian Raeder3, Tobias Reich4, Pascal Schönberg4, and Klaus Wendt1 — 1Institute of Physics, Mainz University — 2GANIL, Caen, France — 3KU Leuven, Belgium — 4Institute for Nuclear Chemistry, Mainz University
The radioactive trace element technetium is one of the dominant fission fragments and therefore might cause radio-toxic threat or, on the other hand, could serve as a long-term indicator of nuclear debris. Nuclear reactors and atomic bombs primarily create the isotope 99Tc with a half-life time of 2.1 · 105 years. Measurements on dissemination in the environment correspondingly require highest significance and selectivity on samples containing only about 1010 atoms or less. Resonant laser ionization is the most suitable approach for this purpose, as it combines high elemental selectivity and highest ionization efficiency widely independent of chemical sample composition.
Successive optical excitation and subsequent ionization following strong unique dipole transitions serves as fingerprint for every element. For this purpose, the detailed knowledge of the hyperfine structure and isotopic shift in the different transitions along the excitation ladders is mandatory, in particular as 97Tc serves as tracer for quantification of analytical results. We examined these parameters for the ground state and energetically higher lying levels in the spectrum of Tc I using a high repetition rate tunable narrow bandwidth titanium:sapphire laser system, to evaluate possible effects on the determined isotopic ratios.