Measurement of Quenching Factors in NaI[Tl]

An overview of nuclear recoil quenching factors is provided, along with a discussion of existing measurements of the quenching of sodium recoils in NaI[Tl]. Next, a measurement is described that took place over several weeks in August and October of 2018. A collaboration consisting of members of the COSINE-100, ANAIS, and COHERENT experiments measured the quenching factor of five NaI crystals grown with different powders and of different sizes. While this is not a definitive test of whether the quenching factor is a property of the specific crystal utilized, the preliminary results show similar quenching between all crystals studied. The final results can be found in D. Cintas, et al., Phys. Rev. C 110, 014613 (2024) and D. Cintas, et al., J. Phys. Conf. Ser. 2156, 012065 (2021). The theses of the other main two collaborators for this measurement can be found at W.G. Thompson, Searching for dark matter with COSINE-100. Yale Graduate School of Arts and Sciences Dissertations, 668 (2022). D. Cintas, New strategies to improve the sensitivity of the ANAIS-112 experiment at the Canfranc Underground Laboratory. arXiv:2310.07339 (2023).