Liquid Argon Ionization Chamber Pulses in a Steady State Ionization Background

The liquid argon in two ionization chambers, each with a gap of 0.27 mm, each with the same potential applied between the two electrodes, and each with identical external circuits, was ionized with an instantaneous pulse of radiation to produce an electrical pulse in each circuit. In the second of the two chambers an additional radiation source also ionized the liquid argon but this one at a constant rate. Here the slowly drifting positive argon ions built up in the gap and distorted the electric field. We report the distorted and degraded pulse shapes observed in the second ionization chamber's circuit compared to the well-understood pulses observed in the first.