The MEG-II experiment searches for the lepton-flavor-violating decay: μ⟶e+γ. The reconstruction of the positron trajectory uses a cylindrical drift chamber operated with a mixture of He and iC4H10 ...gas. It is important to provide a stable performance of the detector in terms of its electron transport parameters, avalanche multiplication, composition and purity of the gas mixture. In order to have a continuous monitoring of the quality of gas, we plan to install a small drift chamber, with a simple geometry that allows to measure very precisely the electron drift velocity in a prompt way. This monitoring chamber will be supplied with gas coming from the inlet and the outlet of the detector to determine if gas contaminations originate inside the main chamber or in the gas supply system. The chamber is a small box with cathode walls, that determine a highly uniform electric field inside two adjacent drift cells. Along the axis separating the two drift cells, four staggered sense wires alternated with five guard wires collect the drifting electrons. The trigger is provided by two 90Sr weak calibration radioactive sources placed on top of a two thin scintillator tiles telescope. The whole system is designed to give a prompt response (within a minute) about drift velocity variations at the 10−3 level.
CMS iRPC FEB development and validation Gouzevitch, M.; El Sawy, M.; Alves, G.A. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
07/2024, Letnik:
1064
Journal Article
Recenzirano
Odprti dostop
In view of the High Luminosity upgrade of the CERN LHC, the forward CMS Muon spectrometer will be extended with two new stations of improved Resistive Plate Chambers (iRPC) covering the ...pseudorapidity range from 1.8 to 2.4. Compared to the present RPC system, the gap thickness is reduced to lower the avalanche charge, and an innovative 2D strip readout geometry is proposed. These improvements will allow iRPC detector to cope with higher background rates. A new Front-End-Board (FEB) is designed to readout iRPC signals with a threshold as low as 30fC and an integrated Time Digital Converter with a resolution of 30ps. In addition, the communication bandwidth is significantly increased by using optical fibers. The history, final design, certification, and calibration of this FEB are presented.
Pressure correction study for the CMS iRPC detector Abdelhameid, T.; Gouzevitch, M.; Tytgat, M. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
02/2024, Letnik:
1059, Številka:
C
Journal Article
Machine Learning based tool for CMS RPC currents quality monitoring Shumka, E.; El Sawy, M.; Alves, G.A. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
09/2023, Letnik:
1054, Številka:
C
Journal Article
Recenzirano
Odprti dostop
The muon system of the CERN Compact Muon Solenoid (CMS) experiment includes more than a thousand Resistive Plate Chambers (RPC). They are gaseous detectors operated in the hostile environment of the ...CMS underground cavern on the Large Hadron Collider where pp luminosities of up to 2×1034cm−2s−1 are routinely achieved. The CMS RPC system performance is constantly monitored and the detector is regularly maintained to ensure stable operation. The main monitorable characteristics are dark current, efficiency for muon detection, noise rate etc. Herein we describe an automated tool for CMS RPC current monitoring which uses Machine Learning techniques. We further elaborate on the dedicated generalized linear model proposed already and add autoencoder models for self-consistent predictions as well as hybrid models to allow for RPC current predictions in a distant future.
The present Compact Muon Solenoid Resistive Plate Chambers system has been worked efficiently during Run I and Run II of data taking period (Shah et al., 2020) 1. In the coming years of operation ...with the High Luminosity LHC (HL-LHC), the expected rate and integrated charge are expected to be about 600 Hz/cm2 and 840 mC/cm2, respectively (including a safety factor of three). Therefore, the HL-LHC phase will be a challenge for the RPC system since the expected operating conditions are much harsher than those for which the detectors have been designed, and could introduce non-recoverable aging effects which can alter the detector properties. A longevity test has been started at the CERN Gamma Irradiation Facility to estimate the impact of HL-LHC conditions on the RPC detector performance in order to determine whether the RPC system will survive the harsher background conditions expected at HL-LHC. The latest results of the irradiation test will be presented.
RPC based tracking system at CERN GIF++ facility Mota Amarilo, K.; Tytgat, M.; Alves, G.A. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
07/2023, Letnik:
1052
Journal Article
Recenzirano
Odprti dostop
With the HL-LHC upgrade of the LHC machine, an increase of the instantaneous luminosity by a factor of five is expected and the current detection systems need to be validated for such working ...conditions to ensure stable data taking. At the CERN Gamma Irradiation Facility (GIF++) many muon detectors undergo such studies, but the high gamma background can pose a challenge to the muon trigger system which is exposed to many fake hits from the gamma background. A tracking system using RPCs is implemented to clean the fake hits, taking profit of the high muon efficiency of these chambers. This work will present the tracking system configuration, used detector analysis algorithm and results.
The MEG-II experiment searches for the lepton flavor violating decay: mu in electron and gamma. The reconstruction of the positron trajectory uses a cylindrical drift chamber operated with a mixture ...of He and iC4H10 gas. It is important to provide a stable performance of the detector in terms of its electron transport parameters, avalanche multiplication, composition and purity of the gas mixture. In order to have a continuous monitoring of the quality of gas, we plan to install a small drift chamber, with a simple geometry that allows to measure very precisely the electron drift velocity in a prompt way. This monitoring chamber will be supplied with gas coming from the inlet and the outlet of the detector to determine if gas contaminations originate inside the main chamber or in the gas supply system. The chamber is a small box with cathode walls, that define a highly uniform electric field inside two adjacent drift cells. Along the axis separating the two drift cells, four staggered sense wires alternated with five guard wires collect the drifting electrons. The trigger is provided by two 90Sr weak calibration radioactive sources placed on top of a two thin scintillator tiles telescope. The whole system is designed to give a prompt response (within a minute) about drift velocity variations at the 0.001 level.
The muon system of the CERN Compact Muon Solenoid (CMS) experiment includes more than a thousand Resistive Plate Chambers (RPC). They are gaseous detectors operated in the hostile environment of the ...CMS underground cavern on the Large Hadron Collider where pp luminosities of up to \(2\times 10^{34}\) \(\text{cm}^{-2}\text{s}^{-1}\) are routinely achieved. The CMS RPC system performance is constantly monitored and the detector is regularly maintained to ensure stable operation. The main monitorable characteristics are dark current, efficiency for muon detection, noise rate etc. Herein we describe an automated tool for CMS RPC current monitoring which uses Machine Learning techniques. We further elaborate on the dedicated generalized linear model proposed already and add autoencoder models for self-consistent predictions as well as hybrid models to allow for RPC current predictions in a distant future.
With the HL-LHC upgrade of the LHC machine, an increase of the instantaneous luminosity by a factor of five is expected and the current detection systems need to be validated for such working ...conditions to ensure stable data taking. At the CERN Gamma Irradiation Facility (GIF++) many muon detectors undergo such studies, but the high gamma background can pose a challenge to the muon trigger system which is exposed to many fake hits from the gamma background. A tracking system using RPCs is implemented to clean the fake hits, taking profit of the high muon efficiency of these chambers. This work will present the tracking system configuration, used detector analysis algorithm and results.
During the upcoming High Luminosity phase of the Large Hadron Collider (HL-LHC), the integrated luminosity of the accelerator will increase to 3000 fb\(^{-1}\). The expected experimental conditions ...in that period in terms of background rates, event pileup, and the probable aging of the current detectors present a challenge for all the existing experiments at the LHC, including the Compact Muon Solenoid (CMS) experiment. To ensure a highly performing muon system for this period, several upgrades of the Resistive Plate Chamber (RPC) system of the CMS are currently being implemented. These include the replacement of the readout system for the present system, and the installation of two new RPC stations with improved chamber and front-end electronics designs. The current overall status of this CMS RPC upgrade project is presented.
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