Hannover 2010 – wissenschaftliches Programm
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A: Fachverband Atomphysik
A 8: Poster I
A 8.10: Poster
Dienstag, 9. März 2010, 16:30–19:00, Lichthof
High Resolution Mass Separation of Cluster Ions — •Kiran Majer1, Lei Ma1,2, and Bernd von Issendorff1 — 1Institut für Physik, Universität Freiburg, 79104 Freiburg, Germany — 2Department of Physics, Nanjing University, 210093 Nanjing, China
In cluster physics most experiments study an observable depending on the cluster size (i. e. number of atoms or molecules composing the cluster), thus requiring an appropriated mass selection prior to the actual experiment. Our existing setup comprises a double reflector time-of-flight (TOF) mass spectrometer, with mass selection after the first reflector and a total flight length of about 4m. The achieved a mass resolution is m/Δ m≈4000. This means for a medium sized cluster of ca. 6000 amu (e.g. Cu91−) the attachment of a hydrogen atom to the cluster can not be detected.
A straightforward approach to improve mass resolution is to increase the flight time elongating the ion flight path. To fit such a system into a common TOF apparatus, the physically given flight path must be used multiple times by reflecting the ions repeatedly between ion mirrors.
We introduce a newly build linear multi-pass reflectron composed of two coaxially arranged electrostatic mirrors. It is set up in series with our existing double reflector TOF, allowing us to enhance mass selectivity on request (according to simulations a mass resolution of 100 000 could be achieved). A comparison of the simulated and experimentally achieved resolution as well as a first application to cluster experiments will be shown.