Berlin 2001 – wissenschaftliches Programm
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A: Atomphysik
A 6: Spectroscopy
A 6.3: Vortrag
Dienstag, 3. April 2001, 16:15–16:30, H1028
First Observation of Optical Transitions in Fermium (Z=100) — •M. Sewtz1, H. Backe1, A. Dretzke1, K. Eberhardt2, C. Grüning2, G. Gwinner3, R. G. Haire4, G. Huber5, J.V. Kratz2, G. Kube1, P. Kunz5, J. Lassen5, W. Lauth1, W. Ludolphs1, A. Morbach1, G. Passler5, R. Repnow3, D. Schwalm3, P. Schwamb1, P. Thörle2, and N. Trautmann2 — 1Institut für Kernphysik, — 2Institut für Kernchemie der Universität Mainz, D-55099 Mainz, Germany — 3Max-Planck-Institut für Kernphysik, D-69029 Heidelberg, Germany — 4ORNL, Oak Ridge, USA — 5Institut für Physik und
Laser spectroscopical studies have been performed for the first time at the element fermium (Z=100). About 1 ng 255Fm with a half-life of 20.1 h was prepared at ORNL, Oak Ridge, USA, by milking from 255Es produced in the high flux reactor and shipped to Mainz. Here a fraction of 2.7 · 1010 atoms were electrodeposited on a Ta filament and covered with 1µm Ti. From the filament the Fm atoms were evaporated at a temparature of about 1000 ∘C in the buffer gas of an optical cell and resonantly ionized with two beams of an excimer-dye-laser combination running with XeF. The resulting ions were identified by mass selective detection employing the Ion-Guide-Quadrupole-Mass Separation (IGQMS) technique, see e.g. [1]. Two resonant transitions were found at energies of 25100 cm−1 and 25112 cm−1. The results will be compared with relativistic MCDF calculations [2]. Work supported by BMBF (06 MZ959I).
[1] H. Backe et al., Nucl. Instr. Meth. B 126, (1997), 406.
[2] S. Fritzsche et al., Comput. Phys. Commun. (1997).