May 19 – 23, 2019

Not scheduled
20m

### Speaker

Dr Henning Back (Pacific Northwest National Laboratory)

### Description

The DarkSide-50 dark matter search experiment demonstrated that argon derived from underground can be highly reduced in $^{39}$Ar, and since then the demand for this commodity has risen. Several fundamental physics experiments need argon that is reduced in $^{39}$Ar as well as $^{42}$Ar, and there are needs in other scientific fields as well (e.g., age-dating). With the increased needs for low-radioactivity underground argon 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 argon from the underground sources of argon through to ensuring that the extracted and purified argon is low in $^{39}$Ar. The broader needs for low-radioactivity underground argon and efforts to procure it will be presented; including the primary producers of underground argon; the DarkSide collaboration. Large-scale isotope separation is also being pursued to further deplete the $^{39}$Ar, as well as next generation technologies in isotope separation through distillation to shrink the size of the columns. We will also show the work being done to quantify the production mechanisms of long-lived radioactive argon isotopes in underground environments and in the atmosphere, and the techniques being pursued for measuring $^{39}$Ar primarily in the age dating community, which are important for quality assurance to ensure the depletion of $^{39}$Ar during the underground production and for searching for new low radioactivity underground argon sources.

### Primary author

Dr Henning Back (Pacific Northwest National Laboratory)