Using the nuclear activation AMS method for determining chlorine in solids at ppb-levels and below

Autor(en)

Stephan R. Winkler, Rosmarie Eigl, Oliver Forstner, Martin Martschini, Peter Steier, Johannes H. Sterba, Robin Golser

Abstrakt

Neutron activation analysis using decay counting of the

activated element is a well-established method in elemental analysis.

However, for chlorine there is a better alternative to measuring decay

of the short-lived activation product chlorine-38 (t_1/2 = 37.24 min) – accelerator mass spectrometry (AMS) of ³⁶Cl:

the relatively high neutron capture cross section of chlorine-35 for

thermal neutrons (43.7 b) and combined the AMS technique for chlorine-36

(t_1/2 = 301 ka) allow for determination of chlorine

down to ppb-levels using practical sample sizes and common exposure

durations. The combination of neutron activation and AMS can be employed

for a few other elements (nitrogen, thorium, and uranium) as well.

For

bulk solid samples an advantage of the method is that lab contamination

can be rendered irrelevant. The chlorine-35 in the sample is activated

to chlorine-36, and surface chlorine can be removed after the

irradiation. Subsequent laboratory contamination, however, will not

carry a prominent chlorine-36 signature. After sample dissolution and

addition of sufficient amounts of stable chlorine carrier the produced

chlorine-36 and thus the original chlorine-35 of the sample can be

determined using AMS.

We have developed and applied

the method for analysis of chlorine in steel samples. The chlorine

content of steel is of interest to nuclear industry, precisely because

of above mentioned high neutron capture cross section for chlorine-35,

which leads to accumulation of chlorine-36 as long-term nuclear waste.

The samples were irradiated at the TRIGA Mark II reactor of the

Atominstitut in Vienna and the ³⁶Cl-AMS setup at the Vienna Environmental Research Accelerator (VERA) was used for ³⁶Cl/Cl analysis.

Organisation(en)

Isotopenphysik, Institut für Anorganische Chemie

Externe Organisation(en)

Technische Universität Wien

Journal

Nuclear Instruments & Methods in Physics Research. Section B. Beam Interactions with Materials and Atoms

Band

361

Seiten

649-653

Anzahl der Seiten

5

ISSN

0168-583X

DOI

https://doi.org/10.1016/j.nimb.2015.06.003

Publikationsdatum

10-2015

Peer-reviewed

Ja

ÖFOS 2012

103014 Kernphysik

Schlagwörter

ASJC Scopus Sachgebiete

Nuclear and High Energy Physics, Instrumentation

Link zum Portal

https://ucris.univie.ac.at/portal/de/publications/using-the-nuclear-activation-ams-method-for-determining-chlorine-in-solids-at-ppblevels-and-below(2e3513d8-19fe-4034-92f6-303422eca1ae).html