Depleted Argon from Underground Sources Available to Purchase

Argon is a strong scintillator and an ideal target for Dark Matter detection; however $39Ar$ contamination in atmospheric argon from cosmic ray interactions limits the size of liquid argon dark matter detectors due to pile‐up. Argon from deep underground is depleted in $39Ar$ due to the cosmic ray shielding of the earth. In Cortez, Colorado, a $CO2$ well has been discovered to contain approximately 600 ppm of argon as a contamination in the $CO2.$ We first concentrate the argon locally to 3% in an Ar, $N2,$ and He mixture, from the $CO2$ through chromatographic gas separation, and then the $N2$ and He will be removed by continuous distillation to purify the argon. We have collected 26 kg of argon from the $CO2$ facility and a cryogenic distillation column is under construction at Fermilab to further purify the argon.