Selective detection of C-13 by laser photodetachment mass spectrometry
2008 (English)In: Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, ISSN 0168-583X, Vol. 266, no 16, 3667-3673 p.Article in journal (Refereed) Published
In this paper, we demonstrate how laser photodetachment mass spectrometry (LPMS) can be used to selectively detect C-13(-) ions in the presence of C-12(-) ions in a low energy ion beam. An isotopically enriched beam of carbon ions consisting of equal amounts of C-13(-) and 12C- ions was extracted from an ion source. The ions interacted with a laser beam in a collinear geometry over a distance of 70 cm. Residual atoms produced in the photodetachment process were detected in a neutral particle detector placed downstream of the collinear interaction region. By making use of the Doppler effect we were able to selectively photodetach C-13(-) ions. The number of detected C-13 atoms was 13 times larger than the number of detected C-12 atoms. The population of the excited, weakly bound D-2 excited state of the C- ion was depleted by the use of a second laser. This significantly reduced the background accompanying the signal arising from the photodetachment of the S-4 ground state C- ion. Different applications of the LPMS method will be discussed in the paper.
Place, publisher, year, edition, pages
2008. Vol. 266, no 16, 3667-3673 p.
negative ion, photodetachment, radiocarbon, isotope selection, mass spectrometry
IdentifiersURN: urn:nbn:se:su:diva-57889DOI: 10.1016/j.nimb.2008.05.126ISI: 000259429100023OAI: oai:DiVA.org:su-57889DiVA: diva2:419016
authorCount :72011-05-252011-05-232011-05-25Bibliographically approved