Detecting Xe in an atmospheric tracer experiment.

The Xcounts algorithm for calculating air concentrations of radioactive xenon isotopes (Eslinger et al., 2023) has been extended to estimate Xe in addition to Xe, Xe, Xe, and Xe. The algorithm was applied to 119 samples collected with a SAUNA Q system (Ringbom et al.

Determining the source of unusual xenon isotopes in samples.

Three unusual radioactive isotopes of xenon-Xe, Xe, and Xe-have been observed during testing of a new generation radioxenon measurement system at the manufacturing facility in Knoxville, Tennessee. These are possibly the first detections of these isotopes in environmental samples collected by automated radioxenon systems. Unfortunately, the new isotopes detected by the Xenon International sampler can interfere with quantification of the radioactive xenon isotopes used to monitor for nuclear explosions.

Trace explosive residue detection of HMX and RDX in post-detonation dust from an open-air environment.

Explosives are often used in industry, geology, mining, and other applications, but it is not always clear what remains after a detonation or the fate and transport of any residual material. The goal of this study was to determine to what extent intact molecules of high explosive (HE) compounds are detectable and quantifiable from post-detonation dust and particulates in a field experiment with varied topography. We focused on HMX (1,3,5,7-Tetranitro-1,3,5,7-tetrazocane), which is less studied in field detonation literature, as the primary explosive material and RDX (1,3,5-Trinitroperhydro-1,3,5-triazine) as the secondary material.

Measurements of Argon-39 at the U20az underground nuclear explosion site.

Pacific Northwest National Laboratory reports on the detection of Ar at the location of an underground nuclear explosion on the Nevada Nuclear Security Site. The presence of Ar was not anticipated at the outset of the experimental campaign but results from this work demonstrated that it is present, along with Ar and Kr in the subsurface at the site of an underground nuclear explosion. Our analysis showed that by using state-of-the-art technology optimized for radioargon measurements, it was difficult to distinguish Ar from the fission product Kr.

The potential detection of low-level aerosol isotopes from new civilian nuclear processes.

As the world faces a challenging future in maintaining the commercial availability of radioactive isotopes for medical use, new methods of medical isotope production are being pursued. Many of these are small in size and could effectively operate continuously. With the potential for much shorter retention times, a new suite of isotopes may soon be found in the environment.