Development of ultra-low mass and high-rate capable RPC based on Diamond-Like Carbon electrodes for MEG II experiment

TL;DR

This paper reports the development of a novel resistive plate chamber with diamond-like carbon electrodes designed for high-rate, low-mass particle detection in the MEG II experiment, demonstrating promising efficiency at high particle flux.

Contribution

It introduces a new resistive plate chamber with segmented diamond-like carbon electrodes, enabling high-rate capability and scalability for particle detection.

Findings

Achieved 1 MHz/cm² rate capability with a single-layer prototype.

Demonstrated 46% detection efficiency with a four-layer prototype at 10 kHz.

Projected 90% efficiency at 4 MHz/cm² with all layers active.

Abstract

A new type of resistive plate chamber with thin-film electrodes based on diamond-like carbon is under development for background identification in the MEG II experiment. Installed in a low-momentum and high-intensity muon beam, the detector is required to have extremely low mass and a high rate capability. A single-layer prototype detector with 2 cm $\times$ 2 cm size was constructed and evaluated to have a high rate capability of 1 MHz/cm$^2$ low-momentum muons. For a higher rate capability and scalability of the detector size, the electrodes to supply high voltage were segmented at a 1 cm pitch by implementing a conductive pattern on diamond-like carbon. Using the new electrodes, a four-layer prototype detector was constructed and evaluated to have a 46% detection efficiency with only a single layer active at a rate of $\cal O$(10 kHz). The result with the new electrodes is promising to achieve the required detection efficiency of 90% at a rate of 4 MHz/cm$^2$ with all the layers active.