Impact of the positive ion current on large size neutrino detectors and delayed photon emission
  Given their small mobility coefficient in liquid argon with respect to the
electrons, the ions spend a considerably longer time in the active volume. We
studied the effects of the positive ion current in a liquid argon time
projection chamber, in the context of massive argon experiments for neutrino
physics. The constant recombination between free ions and electrons produces a
quenching of the charge signal and a constant emission of photons, uncorrelated
in time and space to the physical interactions. The predictions evidence some
potential concerns for multi-ton argon detectors, particularly when operated on
surface
