Atom-at-a-time laser resonance ionization spectroscopy of nobelium.
Optical spectroscopy of a primordial isotope has traditionally formed the basis for understanding the atomic structure of an element. Such studies have been conducted for most elements and theoretical modelling can be performed to high precision, taking into account relativistic effects that scale approximately as the square of the atomic number. However, for the transfermium elements (those with atomic numbers greater than 100), the atomic structure is experimentally unknown. These radioactive elements are produced in nuclear fusion reactions at rates of only a few atoms per second at most and must be studied immediately following their production, which has so far precluded their optical spectroscopy. Here we report laser resonance ionization spectroscopy of nobelium (No; atomic number 102) in single-atom-at-a-time quantities, in which we identify the ground-state transition1S01P1. By combining this result with data from an observed Rydberg series, we obtain an upper limit for the ionization potential of nobelium. These accurate results from direct laser excitations of outer-shell electrons cannot be achieved using state-of-the-art relativistic many-body calculations that include quantum electrodynamic effects, owing to large uncertainties in the modelled transition energies of the complex systems under consideration. Our work opens the door to high-precision measurements of various atomic and nuclear properties of elements heavier than nobelium, and motivates future theoretical work.
Helmholtz-Institut Mainz, Staudingerweg 18, D-55128 Mainz, Germany.|GSI Helmholtzzentrum für Schwerionenforschung GmbH, Planckstrasse 1, D-64291 Darmstadt, Germany.
Mustapha
M
Laatiaoui
Institut für Kernphysik, Johannes Gutenberg-Universität, Johann-Joachim-Becher Weg 45, D-55128 Mainz, Germany.
Werner
W
Lauth
Institut für Kernphysik, Johannes Gutenberg-Universität, Johann-Joachim-Becher Weg 45, D-55128 Mainz, Germany.
Hartmut
H
Backe
Helmholtz-Institut Mainz, Staudingerweg 18, D-55128 Mainz, Germany.|GSI Helmholtzzentrum für Schwerionenforschung GmbH, Planckstrasse 1, D-64291 Darmstadt, Germany.|Institut für Kernchemie, Johannes Gutenberg-Universität, Fritz-Strassmann Weg 2, D-55128 Mainz, Germany.
Michael
M
Block
GSI Helmholtzzentrum für Schwerionenforschung GmbH, Planckstrasse 1, D-64291 Darmstadt, Germany.
Dieter
D
Ackermann
Department of Physics, University of Liverpool, Oxford Street, Liverpool L69 7ZE, UK.
Bradley
B
Cheal
Institut für Angewandte Physik, Technische Universität Darmstadt, Schlossgartenstrasse 7, D-64289 Darmstadt, Germany.
Premaditya
P
Chhetri
Helmholtz-Institut Mainz, Staudingerweg 18, D-55128 Mainz, Germany.|GSI Helmholtzzentrum für Schwerionenforschung GmbH, Planckstrasse 1, D-64291 Darmstadt, Germany.|Institut für Kernchemie, Johannes Gutenberg-Universität, Fritz-Strassmann Weg 2, D-55128 Mainz, Germany.
Christoph Emanuel
CE
Düllmann
KU Leuven, Instituut voor Kern- en Stralingsfysica, Celestijnenlaan 200D, B-3001 Leuven, Belgium.
Piet
P
van Duppen
Helmholtz-Institut Mainz, Staudingerweg 18, D-55128 Mainz, Germany.
Julia
J
Even
KU Leuven, Instituut voor Kern- en Stralingsfysica, Celestijnenlaan 200D, B-3001 Leuven, Belgium.
Rafael
R
Ferrer
Helmholtz-Institut Mainz, Staudingerweg 18, D-55128 Mainz, Germany.|GSI Helmholtzzentrum für Schwerionenforschung GmbH, Planckstrasse 1, D-64291 Darmstadt, Germany.
Francesca
F
Giacoppo
Helmholtz-Institut Mainz, Staudingerweg 18, D-55128 Mainz, Germany.|GSI Helmholtzzentrum für Schwerionenforschung GmbH, Planckstrasse 1, D-64291 Darmstadt, Germany.|Institut für Kernchemie, Johannes Gutenberg-Universität, Fritz-Strassmann Weg 2, D-55128 Mainz, Germany.
Stefan
S
Götz
Helmholtz-Institut Mainz, Staudingerweg 18, D-55128 Mainz, Germany.|GSI Helmholtzzentrum für Schwerionenforschung GmbH, Planckstrasse 1, D-64291 Darmstadt, Germany.
Fritz Peter
FP
Heßberger
KU Leuven, Instituut voor Kern- en Stralingsfysica, Celestijnenlaan 200D, B-3001 Leuven, Belgium.
Mark
M
Huyse
GSI Helmholtzzentrum für Schwerionenforschung GmbH, Planckstrasse 1, D-64291 Darmstadt, Germany.|Institut für Kernphysik, Technische Universität Darmstadt, Schlossgartenstrasse 9, D-64289 Darmstadt, Germany.
Oliver
O
Kaleja
Helmholtz-Institut Mainz, Staudingerweg 18, D-55128 Mainz, Germany.|GSI Helmholtzzentrum für Schwerionenforschung GmbH, Planckstrasse 1, D-64291 Darmstadt, Germany.
Jadambaa
J
Khuyagbaatar
TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada.
Peter
P
Kunz
Institut für Angewandte Physik, Technische Universität Darmstadt, Schlossgartenstrasse 7, D-64289 Darmstadt, Germany.
Felix
F
Lautenschläger
Helmholtz-Institut Mainz, Staudingerweg 18, D-55128 Mainz, Germany.|GSI Helmholtzzentrum für Schwerionenforschung GmbH, Planckstrasse 1, D-64291 Darmstadt, Germany.
Andrew Kishor
AK
Mistry
Helmholtz-Institut Mainz, Staudingerweg 18, D-55128 Mainz, Germany.|GSI Helmholtzzentrum für Schwerionenforschung GmbH, Planckstrasse 1, D-64291 Darmstadt, Germany.|KU Leuven, Instituut voor Kern- en Stralingsfysica, Celestijnenlaan 200D, B-3001 Leuven, Belgium.
Sebastian
S
Raeder
Helmholtz-Institut Mainz, Staudingerweg 18, D-55128 Mainz, Germany.
Enrique Minaya
EM
Ramirez
Institut für Angewandte Physik, Technische Universität Darmstadt, Schlossgartenstrasse 7, D-64289 Darmstadt, Germany.
Thomas
T
Walther
Department of Physics, University of Liverpool, Oxford Street, Liverpool L69 7ZE, UK.
Calvin
C
Wraith
Helmholtz-Institut Mainz, Staudingerweg 18, D-55128 Mainz, Germany.|GSI Helmholtzzentrum für Schwerionenforschung GmbH, Planckstrasse 1, D-64291 Darmstadt, Germany.
Alexander
A
Yakushev