Characterization of liquid argon dopants to optimize dark matter direct detection in DarkSide experiments

Countless astronomical signs point to evidence of dense pockets of mass invisible in the electromagnetic spectrum, but dark matter has evaded observation. Due to limited interactions, it is important for direct detection experiments to be done with high sensitivity and reduced background, such as in the DarkSide collaboration, a group of liquid argon (LAr) based detectors aimed at measuring interactions with dark matter particles through ionization and nuclear interactions. DarkSide-LowMass is a proposed detector aimed at probing lower energy thresholds to find light dark matter particles, done by enhancing the ionization signal. This can be done by introducing dopants in the LAr, optimizing the efficiency of the detector at lower energies. Additionally, nuclear interactions produce scintillation light, detected by silicon photomultipliers (SiPM), where shifting wavelength of scintillation light can improve efficiency of the SiPM. In this project, I develop a sampling chamber used to characterize LAr doping, with an emphasis on ensuring uniformity of the additives in the argon, done by sampling different parts of our cryostat. Next, I will discuss progress towards comparing the efficacy of LAr dopants, such as liquid xenon, tetraphenyl butadiene, and other additives, in optimizing the efficiency of SiPM detectors, and measuring the improvement in the ionization signal. Lastly, I will discuss procedural differences that could guide future R&D in doping LAr for dark matter detection.