Test of Purging a Small Tank with Argon

摘要

One of the challenges facing our large liquid argon TPC is to remove the atmosphere of air to the point where the remaining oxygen can be removed by chemical or filtration techniques economically and in a reasonable time. This note describes a simple demonstration of purging the tank with argon gas inserted smoothly at the bottom of the tank to achieve concentrations of oxygen in the few 10's of ppm level. The purging is well described by an analytic diffusion model. The number of volume changes required to reach 100 ppm is a factor of 3 fewer than predicted in a perfect mixing model.