Feasibility of high-voltage systems for a very long drift in liquid argon TPCs

Designs of high-voltage (HV) systems for creating a drift electric field in liquid argon TPCs are reviewed. In ongoing experiments systems capable of ~100 kV are realised for a drift field of 0.5–1 kV/cm over a length of up to 1.5 m. Two of them having different approaches are presented: the ICARUS-T600 detector having a system consisting of an external power supply, HV feedthroughs and resistive voltage degraders and the ArDM-1t detector having a cryogenic Greinacher HV multiplier inside the liquid argon volume. For a giant scale liquid argon TPC, a system providing 2 MV may be required to attain a drift length of ~ 20 m. Feasibility of such a system is evaluated by extrapolating the existing designs.