Abstract

The Resistive Plate Chambers (RPC) are a part of the muon spectrometer for the Compact Muon Solenoid (CMS) experiment at Large Hadron Collider (LHC). More than 3000 m2 of RPC system was successfully operated with a closed loop gas system in the first three-running-years of the LHC. Annual campaigns were done during 2011 and 2012 to measure the gas leak rates of the RPCs and the results were compared to the flow-cell readout data. The total leak rate on the barrel increased between 2011 and 2012 while the total rate on the endcaps was negligible during the same period. Consequently, the CMS gas consumption increased, but the gas leaks could not be repaired during the whole period of the data taking at the LHC that lasted more than two years. Here, we present the results of the extensive tests for the first long shutdown period of LHC, including the leak detection in the chambers (internal leak) or gas pipes and connectors (external leak), details on the new leak measurement, and the status of a leak repair.

Highlights

  • I N the middle of February 2013, the Large Hadron Collider (LHC) went into a long maintenance stop

  • More than 3000 m2 of Resistive Plate Chambers (RPC) system was successfully operated with a closed loop gas system in the first three-running-years of the LHC

  • Annual campaigns were done during 2011 and 2012 to measure the gas leak rates of the RPCs and the results were compared to the flow-cell readout data

Read more

Summary

INTRODUCTION

I N the middle of February 2013, the Large Hadron Collider (LHC) went into a long maintenance stop. RPCs have been chosen because of their fast time resolution (about 2 ns) and high granularity, which permit a fast and efficient triggering of muons over large areas [1]. They contribute to the identification, reconstruction and tracking of the muons [2]. RPCs are ionizing-particle detectors consisting of two gaps filled up with gas. They are used as dedicated trigger detectors but they contribute to the muon reconstruction at CMS. The closed loop is a critical component of the CMS RPC system

THE GAS LEAK TEST
Identifying leaks on the RPC chambers
Calculating the leak rates
Preliminary results of the gas leak campaign
RPC EFFICIENCY FOR THE LEAKY CHAMBERS
Findings
CONCLUSIONS
Full Text
Published version (Free)

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call