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

Abstract

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 (μRGroove) detector. The μRGroove shares a similar compact stack geometry with the micro-Resistive WELL (μRWELL) 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 μRGroove (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 > 104, 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 μm for 150-GeV/c muons. The μRGroove boasts a compact design and robustness against discharges. Furthermore, compared to the μRWELL, it offers cost savings in detector fabrication and yields significantly higher signal amplitude (approximately double) at the same gas gain. These attributes position the μRGroove as a promising candidate for large-area and low-material-budget tracking applications.