Title of the project: Ion-Laser-Interaction Mass Spectrometry of Cesium Isotopes
Name of the VDSP student: Alexander Wieser
Project supervised by: Robin Golser

I am working at the Vienna Environmental Research Accelerator (VERA), where it is my job to develop a measurement procedure for cesium isotopes. The interest in measuring extremely low levels of a radioactive isotope such as Cs-135 relative to its more prominent sister Cs-137 is strongly increasing. The ratio of these two nuclides can help solve important questions in different scientific fields, e.g. in oceanography, in geochemistry and in nuclear forensics.

Since Cs-135 is a pure beta-emitter with a long half-life of about two million years, radioactivity is so low that very sensitive mass spectrometric methods are needed to measure the Cs-135/Cs-137 ratio. Only accelerator mass spectrometry has the potential of sensing these two radionuclides in environmental samples with the desired detection limit. At VERA with its unique ILIAMS setup, we can suppress the interfering anions Ba-135 and Ba-137 by neutralizing them with a green laser. We already improved the detection limit by several orders of magnitude in the past two years, but there is still plenty of work to be done, until we can establish Cs-135,137 as a powerful environmental marker.

Golser group