The DarkSide-50 dark matter search experiment demonstrated that argon derived from deep underground sources can be highly reduced in 39Ar, and since then the demand for this commodity has risen. Several fundamental physics experiments require argon reduced in 39Ar as well as 42Ar, as well as other rising needs in other scientific fields (e.g., age-dating). With the expanded needs come the questions of availability and how to approach the challenges associated with its production and characterization.
This talk will provide a global picture of low-radioactivity underground argon procurement, from its production to quality control and quality assurance. We will detail the DarkSide-20k plan for extracting more argon from the DarkSide-50 source through a project called Urania, as well as another project which will serve to isotopically separate 39Ar from 40Ar, called Aria.Finally DART is a small (~1 L) chamber that will measure the depletion factor of 39Ar in UAr. The detector will be immersed in the LAr active volume of ArDM (LSC, Spain), which will act as a veto for gammas, allowing a precise measurement of the 39Ar residual activity.