First in-beam studies of a Resistive-Plate WELL gaseous multiplier

We present the results of the first in-beam studies of a medium size (10 × 10 cm 2 ) Resistive-Plate WELL (RPWELL): a single-sided THGEM coupled to a pad anode through a resistive layer of high bulk resistivity (~109 Ωcm). The 6.2 mm thick (excluding readout electronics) single-stage detector was studied with 150 GeV muons and pions. Signals were recorded from 1×1 cm 2 square copper pads with APV25-SRS readout electronics. The single-element detector was operated in Ne/(5%CH4) at a gas gain of a few times 104 , reaching 99% detection efficiency at average pad multiplicity of ~1.2. Operation at particle fluxes up to ~104 Hz/cm 2 resulted in ~23% gain drop leading to ~5% efficiency loss. The striking feature was the discharge-free operation, also in intense pion beams. These results pave the way towards robust, efficient large-scale detectors for applications requiring economic solutions at moderate spatial and energy resolutions.