G. Adhikari, N. Carlin, D.F.F.S. Cavalcante, J.Y. Cho, J.J. Choi, S. Choi, A.C. Ezeribe, L.E. França, C. Ha, I.S. Hahn, S.J. Hollick, E.J. Jeon, H.W. Joo, W.G. Kang, M. Kauer, B.H. Kim, H.J. Kim, J. Kim, K.W. Kim, S.H. Kim, S.K. Kim, S.W. Kim, W.K. Kim, Y.D. Kim, Y.H. Kim, Y.J. Ko, D.H. Lee, E.K. Lee, H. Lee, H.S. Lee, H.Y. Lee, I.S. Lee, J. Lee, J.Y. Lee, M.H. Lee, S.H. Lee, S.M. Lee, Y.J. Lee, D.S. Leonard, N.T. Luan, B.B. Manzato, R.H. Maruyama, R.J. Neal, J.A. Nikkel, S.L. Olsen, B.J. Park, H.K. Park, H.S. Park, J.C. Park, K.S. Park, S.D. Park, R.L.C. Pitta, H. Prihtiadi, S.J. Ra, C. Rott, A. Scarff, K.A. Shin, M.K. Son, N.J.C. Spooner, L.T. Truc, L. Yang, G.H. Yu
COSINE-100 is a dark matter direct detection experiment with 106 kg NaI(Tl) as the target material. 210Pb and daughter isotopes are a dominant background in the WIMP region of interest and are detected via β decay and α decay. Analysis of the α channel complements the background model as observed in the β/γ channel. We present the measurement of the quenching factors and Monte Carlo simulation results and activity quantification of the α decay components of the COSINE-100 NaI(Tl) crystals. The data strongly indicate that the α decays probabilistically undergo two possible quenching factors but require further investigation. The fitted results are consistent with independent measurements and improve the overall understanding of the COSINE-100 backgrounds. Furthermore, the half-life of 216Po has been measured to be 143.4±1.2 ms, which is consistent with and more precise than most current measurements. © 2024 Elsevier B.V.
Department of Physics and Wright Laboratory, Yale University, New Haven, 06520, CT, United States; Physics Institute, University of São Paulo, São Paulo, 05508-090, Brazil; Center for Underground Physics, Institute for Basic Science (IBS), Daejeon, 34126, South Korea; Department of Physics and Astronomy, Seoul National University, Seoul, 08826, South Korea; Department of Physics and Astronomy, University of Sheffield, Sheffield, S3 7RH, United Kingdom; Department of Physics, Chung-Ang University, Seoul, 06973, South Korea; Center for Exotic Nuclear Studies, Institute for Basic Science (IBS), Daejeon, 34126, South Korea; Department of Science Education, Ewha Womans University, Seoul, 03760, South Korea; IBS School, University of Science and Technology (UST), Daejeon, 34113, South Korea; Department of Physics and Wisconsin IceCube Particle Astrophysics Center, University of Wisconsin-Madison, Madison, 53706, WI, United States; Department of Physics, Kyungpook National University, Daegu, 41566, South Korea; Department of Physics, Sejong University, Seoul, 05006, South Korea; Korea Research Institute of Standards and Science, Daejeon, 34113, South Korea; Department of Accelerator Science, Korea University, Sejong, 30019, South Korea; Department of Physics and IQS, Chungnam National University, Daejeon, 34134, South Korea; Department of Physics, Universitas Negeri Malang, Malang, 65145, Indonesia; Department of Physics, Sungkyunkwan University, Suwon, 16419, South Korea; Department of Physics and Astronomy, University of Utah, Salt Lake City, 84112, UT, United States; Department of Physics, University of California San Diego, La Jolla, 92093, CA, United States