Space resolution measurement and threshold calibration of the iRPC detector

Abstract

In preparation for the High-Luminosity upgrade of the LHC, the CMS Muon spectrometer is undergoing an upgrade, incorporating four new stations of improved Resistive Plate Chambers (iRPC) that will extend the pseudo-rapidity coverage to the range of 1.8 to 2.4. The iRPC chambers explore an approach of 2D readout using the readout strips with a signal collection from both sides. A dedicated Front-End Board (FEB) has been designed to read the iRPC signals and tag them in time using a high-precision Time-to-Digital Converter (TDC). This paper presents two new aspects of the FEB characterization on the test bench and the chamber. First, a precise measurement of the charge to threshold calibration for the FEB. Second, the measurement of the space resolution of the FEB on the chamber using cosmic muons. It is concluded that the FEB on the chamber can operate with a threshold around 40 fC, an absolute space resolution between 0.5–1.5 cm, and an absolute time resolution of 500 ps.