Observation of radon mitigation in MicroBooNE by a liquid argon filtration system
Authors: Abratenko P. , Anthony J. , Arellano L. , Asaadi J. , Ashkenazi A. , Balasubramanian S. , Baller B. , Barnes C. , Barr G. , Barrow J. , Basque V. , Bathe-Peters L. , Benevides Rodrigues O. , Berkman S. , Bhanderi A. , Bhat A. , Bhattacharya M. , Bishai M. , Blake A. , Bolton T. , Book J.Y. , Camilleri L. , Caratelli D. , Caro Terrazas I. , Cavanna F. , Cerati G. , Chen Y. , Cianci D. , Conrad J.M. , Convery M. , Cooper-Troendle L. , Crespo-Anadón J.I. , Del Tutto M. , Dennis S.R. , Detje P. , Devitt A. , Diurba R. , Dorrill R. , Duffy K. , Dytman S. , Eberly B. , Ereditato A. , Evans J.J. , Fine R. , Fiorentini Aguirre G.A. , Fitzpatrick R.S. , Fleming B.T. , Foppiani N. , Franco D. , Furmanski A.P. , Garcia-Gamez D. , Gardiner S. , Ge G. , Gollapinni S. , Goodwin O. , Gramellini E. , Green P. , Greenlee H. , Gu W. , Guenette R. , Guzowski P. , Hagaman L. , Hen O. , Hilgenberg C. , Horton-Smith G.A. , Hourlier A. , Itay R. , James C. , Ji X. , Jiang L. , Jo J.H. , Joe C. , Johnson R.A. , Jwa Y.-J. , Kalra D. , Kamp N. , Kaneshige N. , Karagiorgi G. , Ketchum W. , Kirby M. , Kobilarcik T. , Kreslo I. , Lepetic I. , Li J.-Y. , Li K. , Li Y. , Lin K. , Littlejohn B.R. , Louis W.C. , Luo X. , Manivannan K. , Mariani C. , Marsden D. , Marshall J. , Martinez Caicedo D.A. , Mason K. , Mastbaum A. , McConkey N. , Meddage V. , Mettler T. , Miller K. , Mills J. , Mistry K. , Mogan A. , Mohayai T. , Mooney M. , Moor A.F. , Moore C.D. , Mora Lepin L. , Mousseau J. , Mulleriababu S. , Naples D. , Navrer-Agasson A. , Nayak N. , Nebot-Guinot M. , Neely R.K. , Newmark D.A. , Nowak J. , Nunes M. , Palamara O. , Paolone V. , Papadopoulou A. , Papavassiliou V. , Parkinson H.B. , Pate S.F. , Patel N. , Paudel A. , Pavlovic Z. , Piasetzky E. , Ponce-Pinto I.D. , Prince S. , Qian X. , Raaf J.L. , Radeka V. , Rafique A. , Reggiani-Guzzo M. , Ren L. , Rice L.C.J. , Rochester L. , Rodriguez Rondon J. , Rosenberg M. , Ross-Lonergan M. , Rudolf von Rohr C. , Scanavini G. , Schmitz D.W. , Schukraft A. , Seligman W. , Shaevitz M.H. , Sharankova R. , Shi J. , Sinclair J. , Smith A. , Snider E.L. , Soderberg M. , Söldner-Rembold S. , Spentzouris P. , Spitz J. , Stancari M. , St. John J. , Strauss T. , Sutton K. , Sword-Fehlberg S. , Szelc A.M. , Tang W. , Terao K. , Thorpe C. , Torbunov D. , Totani D. , Toups M. , Tsai Y.-T. , Uchida M.A. , Usher T. , Viren B. , Weber M. , Wei H. , White A.J. , Williams Z. , Wolbers S. , Wongjirad T. , Wospakrik M. , Wresilo K. , Wright N. , Wu W. , Yandel E. , Yang T. , Yarbrough G. , Yates L.E. , Yu H.W. , Zeller G.P. , Zennamo J. , Zhang C. , Zuckerbrot M. 
Published: November 2022

The MicroBooNE liquid argon time projection chamber (LArTPC) maintains a high level of liquid argon purity through the use of a filtration system that removes electronegative contaminants in continuously-circulated liquid, recondensed boil off, and externally supplied argon gas. We use the MicroBooNE LArTPC to reconstruct MeV-scale radiological decays. Using this technique we measure the liquid argon filtration system's efficacy at removing radon. This is studied by placing a 500 kBq222Rn source upstream of the filters and searching for a time-dependent increase in the number of radiological decays in the LArTPC. In the context of two models for radon mitigation via a liquid argon filtration system, a slowing mechanism and a trapping mechanism, MicroBooNE data supports a radon reduction factor of greater than 97% or 99.999%, respectively. Furthermore, a radiological survey of the filters found that the copper-based filter material was the primary medium that removed the222Rn. This is the first observation of radon mitigation in liquid argon with a large-scale copper-based filter and could offer a radon mitigation solution for future large LArTPCs.