$In situ ^{77(m)}{Ge}$ production rates for different neutron moderator configurations in the LEGEND-1000 experiment.

Costa I.A., Brugnera R., Di Marco N., Macolino C., Morella M., Salamanna G., Salamida F.
  Giovedì 15/09   15:00 - 18:30   Aula T - Caterina Scarpellini   III - Astrofisica   Presentazione
LEGEND experiment is placed at LNGS in Italy, aiming to suffer less from cosmic radiations. Even so, the $in situ$ production of long-lived isotopes by cosmic muon interactions can generate a non-negligible background. The LEGEND experiment, which searches for $0\upsilon \beta \beta$, foresees the construction of LEGEND-1000, a ton-scale detector, and recent studies have shown that the underground production of $^{77({m})}Ge$ through the rapid capture of neutrons at $^{76}Ge$ may be one of the primary sources of cosmogenic background. Aiming to attenuate these background events and facilitate the work of the tagging and discrimination algorithms, the use of neutron moderators has been investigated. The idea is that the hydrogen-containing neutron moderators behave by slowing down the neutrons produced in the liquid argon, thus increasing the likelihood of them being captured by the argon instead of the germanium detectors, decreasing the $^{77({m})}Ge$ production rate. Using Monte Carlo simulations, four different moderator designs were implemented, and several parameters were evaluated to optimize the moderator screening effect while the background index remained unaffected.