Simulation of the Signal Propagation for Thin-gap RPC in the ATLAS Phase-II Upgrade

TL;DR

This paper models and simulates signal propagation in thin-gap RPCs for the ATLAS Phase-II upgrade, validating the model with measurements and exploring different design geometries to ensure signal integrity.

Contribution

It introduces an analytical model for RPC signal propagation in the ATLAS upgrade, validated by measurements, and applies it to various design geometries including a new readout scheme.

Findings

Simulated characteristic impedance matches measured values.

Model successfully predicts crosstalk in RPCs.

Design optimizations improve signal integrity.

Abstract

Thin-gap Resistive Plate Chambers (RPCs) with a 1 mm gap size are introduced in the Phase-II ATLAS upgrade. Smaller avalanche charge due to the reduced gap size raises concerns for signal integrity. This work focuses on the RPC signal propagation process in lossless conditions, and an analytical study is implemented for the ATLAS RPC. Detector modeling is presented, and the simulation of the RPC signal is discussed in detail. Simulated characteristic impedance and crosstalk have been compared with the measured value to validate this model. This method is applied to different RPC design geometries, including the newly proposed $\eta-\eta$ readout scheme.