The cryogenic RWELL: a stable charge multiplier for dual-phase liquid argon detectors

Abstract

Abstract The operation of a cryogenic Resistive WELL (RWELL) in liquid argon vapor is reported for the first time. It comprises a Thick Gas Electron Multiplier (THGEM) structure coupled to a resistive Diamond-Like Carbon (DLC) anode deposited on an insulating substrate. The multiplier was operated at cryogenic temperature (90 K, 1.2 bar) in saturated argon vapor and characterized in terms of charge gain and electrical stability. A comparative study with standard, non-resistive THGEM (a.k.a LEM) and WELL multipliers confirmed the RWELL advantages in terms of discharge quenching – i.e. superior gain and stability.