WA105: a large-scale demonstrator of the Liquid Argon double phase TPC

First demonstration of a bubble-assisted Liquid Hole Multiplier operation in liquid argon

“…The original goal was to deploy LHM units within a single-phase noble liquid TPC, aiming at simplifying the structure and thus overcoming potential technological issues that may occur in large-volume dual-phase TPC detectors. The latter are the leading instruments in current dark-matter searches [8] and are part of the future neutrino-physics program [9,10].…”

Research and Development Toward Massive Liquid Argon Time Projection Chambers for Neutrino Detection

“…The rings are held at monotonically decreasing negative voltages to create a constant potential gradient from the cathode to the anode. Most TPCs use a wire-based scheme for reading out charge signals [33], although there is significant current interest in using pixel-based readout in a LAr TPC (for example, [34]). A typical TPC readout consists of a Frisch grid [35] to shield the sense wires from induction from far away moving charges and several layers of sense wires oriented at different angles for 2D coordinate determination.…”

“…This process results in an increased signal-to-noise ratio of the readout allowing smaller observable signals and longer drift distances in LAr. The idea has been successfully pursued by several neutrino and dark matter detection experiments (see [34,41,42]).…”

“…WA105 at CERN [34] is, so far, the largest dual phase argon TPC with charge amplification and 2D strip-based projective charge readout in the gas phase. The 3 × 1 × 1 m TPC reads out the amplified charge directly in addition to the primary and secondary scintillation light.…”