@misc{10481/78363,
year = {2022},
month = {10},
url = {https://hdl.handle.net/10481/78363},
abstract = {he 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 kBq 222Rn 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 the 222Rn. 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.},
organization = {Fermi
National Accelerator Laboratory (Fermilab)},
organization = {U.S. Department of Energy},
organization = {Office of Science},
organization = {HEP
User Facility},
organization = {Fermi Research Alliance, LLC (FRA), acting under Contract
No. DE-AC02-07CH11359},
organization = {Offices of High Energy Physics and Nuclear Physics},
organization = {U.S. National
Science Foundation},
organization = {Swiss National Science Foundation},
organization = {Science and Technology Facilities
Council (STFC)},
organization = {United Kingdom Research and Innovation},
organization = {Royal Society (United
Kingdom)},
organization = {European Union’s Horizon 2020 Marie Skłodowska-Curie Actions},
organization = {Albert Einstein
Center for Fundamental Physics},
keywords = {Counting-gas and liquid purification},
keywords = {Gas systems and purification},
keywords = {Noble liquid detectors (scintillation, ionization, double-phase)},
keywords = {Time projection Chambers (TPC)},
title = {Observation of radon mitigation in MicroBooNE by a liquid argon filtration system},
doi = {10.1088/1748-0221/17/11/P11022},
author = {Abratenko, P. and García Gámez, Diego and Microboone Collaboration},
}