# Measurement of the ion fraction and mobility of $^{218}$Po produced in $^{222}$Rn decays in liquid argon **Authors:** P. Agnes, I.F.M. Albuquerque, T. Alexander, A.K. Alton, M. Ave, H.O., Back, G. Batignani, K. Biery, V. Bocci, G. Bonfini, W.M. Bonivento, B., Bottino, S. Bussino, M. Cadeddu, M. Cadoni, F. Calaprice, A. Caminata, N., Canci, A. Candela, M. Caravati, M. Cariello, M. Carlini, M. Carpinelli, S., Catalanotti, V. Cataudella, P. Cavalcante, S. Cavuoti, A. Chepurnov, C., Cicalo, A.G. Cocco, G. Covone, D. D'Angelo, S. Davini, A. De Candia, S. De, Cecco, M. De Deo, G. De Filippis, G. De Rosa, A.V. Derbin, A. Devoto, F. Di, Eusanio, M. D'Incecco, G. Di Pietro, C. Dionisi, M. Downing, D. D'Urso, E., Edkins, A. Empl, G. Fiorillo, K. Fomenko, D. Franco, F. Gabriele, C., Galbiati, C. Ghiano, S. Giagu, C. Giganti, G.K. Giovanetti, O. Gorchakov,, A.M. Goretti, F. Granato, A. Grobov, M. Gromov, M. Guan, Y. Guardincerri, M., Gulino, B.R. Hackett, K. Herner, B. Hosseini, D. Hughes, P. Humble, E.V., Hungerford, Al. Ianni, An. Ianni, V. Ippolito, T.N. Johnson, K. Keeter, C.L., Kendziora, I. Kochanek, G. Koh, D. Korablev, G. Korga, A. Kubankin, M. Kuss,, M. La Commara, M. Lai, X. Li, M. Lissia, G. Longo, A.A. Machado, I.N., Machulin, A. Mandarano, L. Mapelli, S.M. Mari, J. Maricic, C.J. Martoff, A., Messina, P.D. Meyers, R. Milincic, A. Monte, M. Morrocchi, V.N. Muratova, P., Musico, A. Navrer Agasson, A.O. Nozdrina, A. Oleinik, M. Orsini, F. Ortica,, L. Pagani, M. Pallavicini, L. Pandola, E. Pantic, E. Paoloni, K. Pelczar, N., Pelliccia, E. Picciau, A. Pocar, S. Pordes, S.S. Poudel, H. Qian, F. Ragusa,, M. Razeti, A. Razeto, A.L. Renshaw, M. Rescigno, Q. Riffard, A. Romani, B., Rossi, N. Rossi, D. Sablone, O. Samoylov, W. Sands, S. Sanfilippo, C., Savarese, B. Schlitzer, E. Segreto, D.A. Semenov, A. Shchagin, A. Sheshukov,, P.N. Singh, M.D. Skorokhvatov, O. Smirnov, A. Sotnikov, C. Stanford, S., Stracka, Y. Suvorov, R. Tartaglia, G. Testera, A. Tonazzo, P. Trinchese, E.V., Unzhakov, M. Verducci, A. Vishneva, R.B. Vogelaar, M. Wada, T.J. Waldrop, H., Wang, Y. Wang, A.W. Watson, S. Westerdale, M.M. Wojcik, X. Xiang, X. Xiao, C., Yang, Z. Ye, C. Zhu, G. Zuzel arXiv: 1907.09332 · 2019-11-15 ## TL;DR This study measures the fraction of charged $^{218}$Po ions and their mobility in liquid argon, providing valuable data for understanding radon decay products in dark matter detectors. ## Contribution It provides the first precise measurements of the charged fraction and mobility of $^{218}$Po ions in liquid argon, relevant for background modeling in dark matter experiments. ## Key findings - Charged fraction of $^{218}$Po is 0.37±0.03. - Mobility of $^{218}$Po$^+$ ions is (8.6±0.1)×10$^{-4}$ cm$^2$/Vs. - Data obtained from 532 live-days of DarkSide-50 data. ## Abstract We report measurements of the charged daughter fraction of $^{218}$Po as a result of the $^{222}$Rn alpha decay, and the mobility of $^{218}$Po$^+$ ions, using radon-polonium coincidences from the $^{238}$U chain identified in 532 live-days of DarkSide-50 WIMP-search data. The fraction of $^{218}$Po that is charged is found to be 0.37$\pm$0.03 and the mobility of $^{218}$Po$^+$ is (8.6$\pm$0.1)$\times$10$^{-4}$$\frac{\text{cm}^2}{\text{Vs}}$. ## Full text _Full body text omitted from this summary view._ Fetch the complete paper as Markdown: https://tomesphere.com/paper/1907.09332/full.md ## Figures 8 figures with captions in the complete paper: https://tomesphere.com/paper/1907.09332/full.md ## References 21 references — full list in the complete paper: https://tomesphere.com/paper/1907.09332/full.md --- Source: https://tomesphere.com/paper/1907.09332