Gamma-ray bursts (GRBs) are highly energetic explosions signaling the death of massive stars in distant galaxies. The Gamma-ray Burst Monitor and Large Area Telescope onboard the Fermi Observatory together record GRBs over a broad energy range spanning about 7 decades of gammaray energy. In September 2008, Fermi observed the exceptionally luminous GRB… (More)
The formation of highly reactive compounds in the gas mixture during Resistive Plate Chambers (RPCs) operation at the CERN Gamma Irradiation Facility (GIF) is studied. Results from two different types of chambers are discussed: 50 x 50 cm 2 RPC prototypes and two final CMS-RB1 chambers. The RB1 detectors were also connected to a closed loop gas system. Gas… (More)
The Resistive Plate Chambers (RPC) detector of the CMS experiment at the LHC proton collider (CERN, Switzerland) will employ an online gas analysis and monitoring system of the freon-based gas mixture used. We give an overview of the CMS RPC gas system, describe the project parameters and first results on gas-chromatograph analysis. Finally, we report on… (More)
The CMS Barrel resistive plate chambers quality tests are performed at three different sites (Bari, Pavia and Sofia), where equivalent software and hardware tools are used. Data from the first 210 detectors are available for a comprehensive analysis. The paper describes the general experimental setup , the test procedure and the cosmic muon test results.… (More)
Several small single gap Resistive Plate Chambers and two RB1 CMS final stations have been exposed during the last year at the CERN Gamma Irradiation Facility to study possible long-term ageing effects. Up to now, an integrated charge of about 0:05 C=ðcm 2 gapÞ and 0.025 C/(cm 2 gap) has been accumulated for the small RPCs and the large RB1 stations,… (More)
The CMS detector at the LHC has a redundant muon system. Two independent muon systems are used in the L1 trigger. One of them is based on wire chambers, the other on RPC detectors. Properly combining the answers of the two systems results in a highly efficient L1 trigger with high flexibility from the point of view of rate control. Simulation results show,… (More)
A model to simulate the avalanche formation process and the induced signal in a Resistive Plate Chamber is presented. A "rst investigation of the e!ects of various parameters on the performance of this detector is reported. 1999 Published by Elsevier Science B.V. All rights reserved.
A double gap Bakelite Resistive Plate Chamber (RPC) with common readout has been exposed to the radiation emitted from a 252 Cf source to measure its neutron and γ sensitivity. RPC signals were triggered by fission events detected using BaF 2 scintillators. A GEANT 3.21 Monte Carlo code with MICAP interface estimated the γ and neutron contributions to the… (More)
A 3 mm wide-gap Resistive Plate Chamber, as proposed for CMS, has been tested in the H2 Cern beam line. Results on efficiency, rate capability, time resolution and cluster size are reported. 1998 Elsevier Science B.V. All rights reserved.