  We study the compatibility of the observed DAMA modulation signal with
inelastic scattering of dark matter (DM) off of the $0.1\%$ Thallium (Tl)
dopant in DAMA. In this work we test whether there exist regions of parameter
space where the Tl interpretation gives a good fit to the most recent data from
DAMA, and whether these regions are compatible with the latest constraints from
other direct detection experiments. Previously, Chang et al. in 2010, had
proposed the Tl interpretation of the DAMA data, and more recently (in 2019)
the DAMA/LIBRA collaboration found regions in parameter space of Tl inelastic
scattering that differ by more than $10\sigma$ from a no modulation hypothesis.
We have expanded upon their work by testing whether the regions of parameter
space where inelastic DM-Tl scattering gives a good fit to the most recent DAMA
data survive the constraints placed by the lack of a DM signal in XENON1T and
CRESST-II. In addition, we have tested how these regions change with the main
sources of uncertainty: the Tl quenching factor, which has never been measured
directly, and the astrophysical uncertainties in the DM distribution. We
conclude that inelastic DM scattering off Tl cannot explain the DAMA data in
light of null results from other experiments.
