The micro-resistive groove detector: a new compact single amplification-stage MPGD

In this paper, we introduce a novel single amplification-stage Micro-Pattern Gaseous Detector (MPGD) that incorporates a Diamond-Like Carbon (DLC)-based resistive electrode at the bottom of micro-groove structures, the micro-Resistive Groove ( μ RGroove) detector. The μ RGroove shares a similar compact stack geometry with the micro-Resistive WELL ( μ RWELL) detector, but it distinguishes itself by employing a groove structure for charge amplification instead of a well. The top metal layer of the grooves naturally forms an array of strips. By incorporating additional 1-dimensional (1D) readout strips beneath the DLC electrode, a 2-dimensional (2D) strip-readout scheme can be easily implemented. Two prototypes of the μ RGroove (10 cm× 10 cm) were manufactured in 2022 at CERN, and their performance was evaluated through X-ray and beam tests. The results indicate a gas gain > 10 4 , an energy resolution of ~ 25%, and negligible charging-up effects for 8 keV Cu X-rays. Additionally, the detection efficiency was found to be ~ 95%, with a position resolution of ∼ 75 μ m for 150-GeV/c muons. The μ RGroove boasts a compact design and robustness against discharges. Furthermore, compared to the μ RWELL, it offers cost savings in detector fabrication and yields significantly higher signal amplitude (approximately double) at the same gas gain. These attributes position the μ RGroove as a promising candidate for large-area and low-material-budget tracking applications.