SAUNA Q_B - Array: The realization of a new concept in radioxenon detection

We introduce a new concept in radioxenon detection - the radioxenon Array, defined as a system where air sampling and activity measurement is performed at multiple locations, using measurement units that are less sensitive, but on the other hand less costly, and easier to install and operate, compared to current state-of-the-art radioxenon systems. The inter-unit distance in the Array is typically hundreds of kilometres. Using synthetic nuclear explosions together with a parametrized measurement system model, we argue that, when such measurement units are combined into an Array, the aggregated verification performance (detection, location, and characterization) can be high. The concept has been realized by developing a measurement unit named SAUNA Q_B, and the world's first radioxenon Array is now operating in Sweden. The operational principles and performance of the SAUNA Q_B and the Array is described, and examples of first measured data are presented, indicating a measurement performance according to expectations.