Radioxenon for the detection of nuclear weapons tests

The noble gas Xenon has proven itself as very useful tool in the verification regime of the Comprehensive-Test-Ban Treaty. This holds especially true for the detection of underground nuclear explosions and the distinction between a nuclear and a chemical explosion.

Therefore, the project refines a categorization concept for radioxenon spectra, as used by the CTBTO, und creates an algorithm which conducts them automatically. These spectra provide information on the xenon concentration in the examined air, and are categorized depending on their significance for nuclear tests. The categorization concept is mainly based on the proportion between specific relevant xenon isotopes and not on the overall xenon concentration

The algorithm is now being evaluated for its ability to detect underground nuclear weapons tests, because these kinds of tests are usually the ones that are the hardest to verify. Therefore, genuine xenon measurements from the Nevada Test Site (USA) are used, which were taken from underground nuclear tests prior to the CTBT. Assuming that these measured and identical xenon concentrations would be released today, their distribution in the atmosphere is simulated using meteorological data. The concentrations, which are detected by certain noble gas detectors in the current monitoring network, are added to the actually measured concentrations, and the sum is categorized with the algorithm.