Testing sTGC with small angle wire edges for the ATLAS New Small Wheel Muon Detector Upgrade

TL;DR

This paper investigates the performance of small-strip Thin Gap Chambers (sTGC) with small angle wire edges for the ATLAS Muon Detector upgrade, focusing on edge effects and detector stability under high-luminosity conditions.

Contribution

It presents experimental tests of sTGC edge effects and stability, highlighting potential issues and guiding future detector design improvements.

Findings

sTGC is stable with no sparks observed

Some response differences near the detector edge detected

Further studies needed to understand edge effects

Abstract

The LHC upgrade scheduled for 2018 is expected to significantly increase the accelerator's luminosity, and as a result the radiation background rates in the ATLAS Muon Spectrometer will increase too. Some of its components will have to be replaced in order to cope with these high rates. Newly designed small-strip Thin Gap chambers (sTGC) will replace them at the small wheel region. One of the differences between the sTGC and the currently used TGC is the alignment of the wires along the azimuthal direction. As a result, the outermost wires approach the detector's edge with a small angle. Such a configuration may be a cause for various problems. Two small dedicated chambers were built and tested in order to study possible edge effects that may arise from the new configuration. The sTGC appears to be stable and no spark have been observed, yet some differences in the detector response near the edge is seen and further studies should be carried out.