First studies with the Resistive-Plate WELL gaseous multiplier

We present the results of first studies of the Resistive Plate WELL (RPWELL): a single-faced THGEM coupled to a copper anode via a resistive layer of high bulk resistivity. We explored various materials of different bulk resistivity (10⁹−10¹² Ωcm) and thickness (0.4−4 mm). Our most successful prototype, with a 0.6 mm resistive plate of ∼ 10⁹ Ωcm, achieved gains of up to 10⁵ with 8 keV x-ray in Ne/5%CH₄; a minor 30% gain drop occurred with a rate increase from 10 to 10⁴ Hz/mm². The detector displayed a full ``discharge-free'' operation — even when exposed to high primary ionization events. We present the RPWELL detector concept and compare its performance to that of other previously explored THGEM configurations — in terms of gain, its curves, dependence on rate, and the response to high ionization. The robust Resistive Plate WELL concept is a step forward in the Micro-Pattern Gas-Detector family, with numerous potential applications.