Ar-39 Detection at the 10^-16 Isotopic Abundance Level with Atom Trap Trace Analysis

TL;DR

This paper demonstrates a highly sensitive laser-based atom counting method, ATTA, capable of detecting atmospheric Ar-39 at an isotopic abundance of 8x10^-16, enabling advanced applications in dating and dark matter research.

Contribution

The paper introduces improved ATTA techniques achieving two orders of magnitude better efficiency and selectivity for Ar-39 detection at extremely low isotopic levels.

Findings

Achieved detection of Ar-39 at 8x10^-16 abundance.

Enhanced counting rate and efficiency by 100 times.

Enabled new applications in dating and dark matter detection.

Abstract

Atom Trap Trace Analysis (ATTA), a laser-based atom counting method, has been applied to analyze atmospheric Ar-39 (half-life = 269 yr), a cosmogenic isotope with an isotopic abundance of 8x10^-16. In addition to the superior selectivity demonstrated in this work, counting rate and efficiency of ATTA have been improved by two orders of magnitude over prior results. Significant applications of this new analytical capability lie in radioisotope dating of ice and water samples and in the development of dark matter detectors.