https://doi.org/10.1140/epjd/e2004-00024-4
Efficient three-step, two-color ionization of plutonium using a resonance enhanced 2-photon transition into an autoionizing state
1
Institut für Physik, Universität Mainz, 55099 Mainz, Germany
2
Institut für Kernchemie, Universität Mainz, 55099 Mainz, Germany
Corresponding author: a pkunz@mail.uni-mainz.de
Received:
30
October
2003
Revised:
6
January
2004
Published online:
24
February
2004
Resonance ionization mass spectrometry (RIMS) has
proven to be a powerful method for isotope selective ultra-trace
analysis of long-lived radioisotopes. For plutonium detection
limits of 
to 
atoms have been achieved
for various types of samples. So far a three-step, three-color
laser excitation scheme was applied for efficient ionization. In
this work, a two-photon transition from an excited state into a
high-lying autoionizing state, will be presented, yielding a
similar overall efficiency as the three-step, three-color
ionization scheme. In this way, only two tunable lasers are
needed, while the advantages of a three-step, three-color
excitation (high selectivity, good efficiency and low non-resonant
background) are preserved. The two-photon transition has been
characterized with respect to saturation behavior and line width.
The three-step, two-color ionization is a possibility for an
improved RIMS procedure.
PACS: 82.80.Ms – Mass spectrometry (including SIMS, multiphoton ionization and resonance ionization mass spectrometry, MALDI) / 32.80.Rm – Multiphoton ionization and excitation to highly excited states (e.g., Rydberg states) / 32.80.Dz – Autoionization
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2004
