Fabrication and performance of a μRWELL detector with Diamond-Like Carbon resistive electrode and two-dimensional readout

The Micro-Resistive WELL (mu RWELL) detector is a novel spark-protected Micro-Pattern Gaseous Detector (MPGD) with a single well-type amplification stage. By integrating a well-type amplification structure with a resistive electrode on a readout board (mu RWELL PCB), the mu RWELL detector is only composed of a cathode PCB and a mu RWELL PCB, resulting in a very simple assembling process without any gluing, stretching, tensioning or other complicated operation commonly practiced in assemblies of other MPGDs. A critical component of the mu RWELL detector is the resistive electrode that is responsible for spark suppression, and hence maintains stable operation of the detector. In this paper, we present a 10 cm x 10 cm mu RWELL detector with two layers readout strips perpendicular to each other. Its resistive electrode is made of a thin coating of Diamond-Like Carbon by magnetron sputtering technique. The gain performance and rate capability of this mu RWELL detector were systematically studied with X-rays, and its detection efficiency and spatial resolution were measured with a test beam. The detector can achieve a spatial resolution better than 70 mu m in both dimensions while the detection efficiency is higher than 90%.