The ILIAS project for selective isobar suppression by laser photodetachment
Artikel i vetenskaplig tidskrift, 2015

Laser photodetachment is the process when the extra electron of a negative ion is removed by means of laser radiation. This can happen only if the photon energy is larger than the electron affinity of the ion. The process can be used in mass spectrometry to selectively suppress unwanted isobars, provided that the electron affinity of the unwanted isobar is lower than that of the isobar under investigation. At the Ion Laser InterAction Setup (ILIAS) at the University of Vienna laser photodetachment of negative atomic and molecular ions is studied and its applicability for selective isobar suppression in accelerator mass spectrometry (AMS) is evaluated. The setup provides mass separated beams of negative ions with energies up to 30 keV. Negative ions are produced in a Middleton type cesium sputter ion source, mass selected and overlapped with a strong continuous wave laser beam. In order to extend the interaction time of ions and laser, the ion beam is decelerated to thermal energies in a gas-filled radio frequency quadrupole cooler. For an appropriate choice of the photon energy, unwanted isobars are neutralized while the isobar of interest is unaffected and remains negatively charged. A description of the ILIAS setup and results from the commissioning phase of the RFQ cooler are presented. Up to 8% ion beam transmission could be achieved after a recent redesign of the extraction system. Furthermore first results of photodetachment experiments of 63Cu− within the RFQ cooler are presented.

Isobar suppression

Laser photodetachment

Accelerator mass spectrometry

Författare

O. Forstner

Universität Wien

Stefan-Meyer-Institut fur subatomare Physik

Friedrich-Schiller-Universität Jena

Pontus Andersson

Chalmers, Rymd- och geovetenskap, Optisk fjärranalys

Dag Hanstorp

Göteborgs universitet

Johannes Lahner

Universität Wien

Martin Martschini

Universität Wien

Johanna Pitters

Universität Wien

Alfred Priller

Universität Wien

Peter Steier

Universität Wien

Robin Golser

Universität Wien

Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms

0168-583X (ISSN)

Vol. 361 217-221

Ämneskategorier

Fysik

Atom- och molekylfysik och optik

DOI

10.1016/j.nimb.2015.04.021