Light induced suppression of sulfur in a cesium sputter ion source

Autor(en)

Martin Martschini, Johan Rohlén, Pontus Andersson, Robin Golser, Dag Hanstorp, Anton Lindahl, Alfred Priller, Peter Steier, Oliver Forstner

Abstrakt

New techniques for suppression of atomic isobars in negative ion beams are of great interest for accelerator mass spectrometry (AMS). Especially small and medium-sized facilities can significantly extend their measurement capabilities to new interesting isotopes with a technique independent of terminal voltage. In a new approach, the effect of continuous wave laser light directed towards the cathode surface in a cesium sputter ion source of the Middleton type was studied. The laser light induced a significant change in oxygen, sulfur and chlorine negative ion production from a AgCl target. Approximately 100 mW of laser light reduced the sulfur to chlorine ratio by one order of magnitude. The effect was found to depend on laser power and ion source parameters but not on the laser wavelength. The time constant of the effect varied from a few seconds up to several minutes. Experiments were first performed at the ion beam facility GUNILLA at University of Gothenburg with macroscopic amounts of sulfur. The results were then reproduced at the VERA AMS facility with chemically cleaned AgCl targets containing similar to 1 ppm sulfur. The physical explanation behind the effect is still unclear. Nevertheless, the technique has been successfully applied during a regular AMS measurement of Cl-36.

Organisation(en)

Isotopenphysik

Externe Organisation(en)

University of Gothenburg

Journal

International Journal of Mass Spectrometry

Band

315

Seiten

55-59

Anzahl der Seiten

5

ISSN

1387-3806

DOI

https://doi.org/10.1016/j.ijms.2012.02.023

Publikationsdatum

2012

Peer-reviewed

Ja

ÖFOS 2012

1030 Physik, Astronomie

Link zum Portal

https://ucris.univie.ac.at/portal/de/publications/light-induced-suppression-of-sulfur-in-a-cesium-sputter-ion-source(01526b3a-0762-40d8-b717-ad6cf35df602).html