ISSN:
1434-6079
Keywords:
36.40.+d
;
35.20
Source:
Springer Online Journal Archives 1860-2000
Topics:
Physics
Notes:
Abstract Stoichiometric and non-stoichiometric negatively charged CO2 cluster ions have been produced in a crossed neutral cluster/electron beam ion source. The abundance and stability of these ions have been studied with a double focussing sector field mass spectrometer. The observed abundance anomalies (“magic numbers”) in the mass spectra of (CO2) n − and (CO2) n O− ions correlate with corresponding small and large metastable fractions of these ions (for loss of one CO2 unit). Variation of the measured metastable fractions as a function ofn are related to corresponding changes in the monomer binding energies. In addition, we have observed for the first time (CO2) n O 2 − ions (i.e. at electron energies above 8 eV with an energy resonance at about 14 eV) and we discuss possible production mechanisms for these ions. Relative electron attachment cross sections have been determined in the energy regime O〈E≦20 eV for (CO2) n − , (CO2) n O− and (CO2) n O 2 − withn=1 to 20. The shape of the cross section function for (CO2) n O− is strongly dependent on the cluster sizen.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01425751
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