Searching for Dark Matter with Doe Canyon Argon

1. Searching for Dark Matter with Doe Canyon Argon Dr. Henning O. Back Urania/Kinder Morgan meeting March 5, 2019

2. The mass in the universe • Normal • matter • Galaxies • Stars • Planets • Earth • Moon • House • Car • Grandma • Everything you have every • Dark • matter • ????? All mass in the Universe =

3. The mass in the universe 85% 15% • Normal • matter • Galaxies • Stars • Planets • Earth • Moon • House • Car • Grandma • Everything you have every • Dark • matter • ????? All mass in the Universe =

4. The mass in the universe 85% 15% • Normal • matter • Galaxies • Stars • Planets • Earth • Moon • House • Car • Grandma • Everything you have every Dark matter We think it is a Weakly Interacting Massive Particle (WIMP) All mass in the Universe =

5. Measuring radiation with argon e- β’/γ’ β/γ electronic recoil χ’/n’ Boulay and Hime, Astropart. Phys. 25 (2006) 179 χ/n nuclear recoil Dark matter will only scatter off of argon nucleus Recoiling nucleus cause argon excitation and ionization

6. Argon dark matter detectors DarkSide-50 DEAP3600 Sensitive light detectors Sensitive light detectors Argon Argon Sensitive light detectors

7. Global argon dark matter landscape MiniCLEAN (PNNL) DarkSide-20k DarkSide-50 (PNNL) ArDM Data taking 2022 DEAP-3600

8. The trouble with argon Banana comparison: 150 Bq/kg of potassium-40

9. Terrestrial argon Atmosphere (8×10-16 39Ar/40Ar) Crust – 1ppm U and Th (low 39Ar) Mantle Low U and Th (lowest 39Ar) • 40Ar comes from 40K decay • Atmosphere • 39Ar produced by cosmic ray neutrons • 40Ar(n, 2n)39Ar • Crust • No cosmic rays • Neutrons from U and Th • Mantle • Very low U and Th • Lowest 39Ar levels

10. The Doe Canyon argon“Going deep” X1400 reduction in 39Ar Phys. Rev. D 93, 081101(R) (2016) CO2 is from the mantle Contain 440 ppm argon

11. DarkSide-50 target productionUAr extraction - Colorado Vacuum-Pressure Swing Adsorption He, Ar, N2 mixture Gas flows through one column under pressure. CO2, H2O and CH4 are adsorbed on zeolite Simultaneously the other column is pumped on to remove the trapped gases • Approximate product composition: • He – 85-95% • Ar– 3-6% • N2– 1-10% • Average production rate: • 140 g/day Zeolite column Zeolite column Adsorbed gas returned to company Gas from well

12. DarkSide-50 target productionUAr purification –Fermilab, Illinois, USA Vent Transportation cylinder racks Booster Waste CB Charcoal Trap (CBCT) Storage Product Input pumped out Booster Product Waste Waste Condenser Buffer Volume Condenser Booster Helium Separator (CB) CDF Organics Cold Traps Cryogenic Distillation Column (CDC) Oxygen Getter Input Product Input Product Input Input Product Reboiler Vent 1 kg/day Final Product ~100% UAr After He separation order-of: 40% Ar, 60% N2 6 kg/day Colorado gas 3-6% Ar, 1-10% N2, 85-95% He

13. DarkSide-50 target productionUAr purification –Fermilab, Illinois, USA Vent Transportation cylinder racks Booster Waste CB Charcoal Trap (CBCT) Storage Product Input pumped out Booster Product Waste Waste Condenser Buffer Volume Condenser Booster Helium Separator (CB) CDF Organics Cold Traps Cryogenic Distillation Column (CDC) Oxygen Getter Input Product Input Product Input Input Product Reboiler Vent 1 kg/day Final Product ~100% UAr After He separation order-of: 40% Ar, 60% N2 6 kg/day Colorado gas 3-6% Ar, 1-10% N2, 85-95% He Total production: 184 kg

14. The end DarkSide-50 UAr production Vacuum-pressure swing adsorption Cryogenic distillation column March 2016 Fall 2010 Jan. 2016

15. DarkSide-20k target production • Urania(planned) • Extracts argon from CO2 • Same source as DarkSide-50 target • Production: • 250 kg/day • 99.9% pure • Aria(under construction) • Final argon purification • Capable of isotope separation (39Ar depletion) • Located in the Seruci mine in Sardinia, Italy

16. Meeting agenda Meeting Goals Update project status Identify action items Identify responsible on Urania team and KM team