
Dark Matter Experiment Finds Unexplained Signal - theafh
https://www.quantamagazine.org/dark-matter-experiment-finds-unexplained-signal-20200617/
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yummypaint
Tritium has a half life of around 12 years, and they saw 53 excess counts over
a year. To be explained by tritium decay, there would only need to be 1000
atoms of contamination. These types of low background experiments are build
from some of the purest and cleanest objects ever manufactured. However,
electron recoils weren't a focus in the design of the experiment, much of
which is focused on reducing backgrounds. Tritium is just hydrogen chemically,
which has a tendency to exchange with hydrogen in organic compounds, and can
be innadvertantly captured by metals and later released. This is a pretty
pernicious problem to deal with and i really feel for the students. If it is
tritium, letting everything run for a long time and looking for a time
dependent effect is a possible approach, but this isn't very compatible with
phD timelines, and the xenon will probably be in demand elsewhere.

