Subscribe to the gold package and get unlimited access to Shamra Academy
Register a new userModeling the triple-GEM detector response to background particles for the CMS Experiment
113
0
0.0
(
0
)
Added by
Sushil Singh Chauhan
Publication date
2021
fields
Physics
and research's language is
English
Ask ChatGPT about the research
No Arabic abstract
An estimate of environmental background hit rate on triple-GEM chambers is performed using Monte Carlo (MC) simulation and compared to data taken by test chambers installed in the CMS experiment (GE1/1) during Run-2 at the Large Hadron Collider (LHC). The hit rate is measured using data collected with proton-proton collisions at 13 TeV and a luminosity of 1.5$times10^{34}$ cm$^{-2}$ s$^{-1}$. The simulation framework uses a combination of the FLUKA and Geant4 packages to obtain the hit rate. FLUKA provides the radiation environment around the GE1/1 chambers, which is comprised of the particle flux with momentum direction and energy spectra ranging from $10^{-11}$ to $10^{4}$ MeV for neutrons, $10^{-3}$ to $10^{4}$ MeV for $gamma$s, $10^{-2}$ to $10^{4}$ MeV for $e^{pm}$, and $10^{-1}$ to $10^{4}$ MeV for charged hadrons. Geant4 provides an estimate of detector response (sensitivity) based on an accurate description of detector geometry, material composition and interaction of particles with the various detector layers. The MC simulated hit rate is estimated as a function of the perpendicular distance from the beam line and agrees with data within the assigned uncertainties of 10-14.5%. This simulation framework can be used to obtain a reliable estimate of background rates expected at the High Luminosity LHC.
rate research
Read More
The Phase-II high luminosity upgrade to the Large Hadron Collider (LHC) is planned for 2023, significantly increasing the collision rate and therefore the background rate, particularly in the high $eta$ region. To improve both the tracking and triggering of muons, the Compact Muon Solenoid (CMS) Collaboration plans to install triple-layer Gas Electron Multiplier (GEM) detectors in the CMS muon endcaps. Demonstrator GEM detectors were installed in CMS during 2017 to gain operational experience and perform a preliminary investigation of detector performance. We present the results of triple-GEM detector performance studies performed in situ during normal CMS and LHC operations in 2018. The distribution of cluster size and the efficiency to reconstruct high $p_T$ muons in proton--proton collisions are presented as well as the measurement of the environmental background rate to produce hits in the GEM detector.
The third generation of the Beijing Electron Spectrometer, BESIII, is an apparatus for high energy physics research. The hunting of new particles and the measurement of their properties or the research of rare processes are sought to understand if the measurements confirm the Standard Model and to look for physics beyond it. The detectors ensure the reconstruction of events belonging to the sub-atomic domain. The operation and the efficiency of the BESIII inner tracker is compromised due to the the radiation level of the apparatus. A new detector is needed to guarantee better performance and to improve the physics research. A cylindrical triple-GEM detector (CGEM) is an answer to this need: it will maintain the excellent performance of the inner tracker while improving the spatial resolution in the beam direction allowing a better reconstruction of secondary vertices. The technological challenge of the CGEM is related in its spatial limitation and the needed cylindrical shape. At the same time the detector has to ensure an efficiency close to 1 and a stable spatial resolution better than 150 $mu$m, independently from the track incident angle and the presence of 1 T magnetic field. In the years 2014-2018 the CGEM-IT has been designed and built. Through several test beam and simulations the optimal configuration from the geometrical and electrical points of view has been found. This allows to measure the position of the charged particle interacting with the CGEM-IT. Two algorithms have been used for this purpose, the charge centroid and the $mu$TPC, a new technique introduced by ATLAS in MicroMegas and developed here for the first time for triple-GEM detector. A complete triple-GEM simulation software has been developed to improve the knowledge of the detection processes. The software reproduces the CGEM-IT behavior in the BESIII offline software.
Optical readout of GEM based devices by means of high granularity and low noise CMOS sensors allows to obtain very interesting tracking performance. Space resolution of the order of tens of $mu$m were measured on the GEM plane along with an energy resolution of 20%$div$30%. The main limitation of CMOS sensors is represented by their poor information about time structure of the event. In this paper, the use of a concurrent light readout by means of a suitable photomultiplier and the acquisition of the electric signal induced on the GEM electrode are exploited to provide the necessary timing informations. The analysis of the PMT waveform allows a 3D reconstruction of each single clusters with a resolution on z of 100 $mu$m. Moreover, from the PMT signals it is possible to obtain a fast reconstruction of the energy released within the detector with a resolution of the order of 25% even in the tens of keV range useful, for example, for triggering purpose.
The LHC is undergoing a high luminosity upgrade, which is set to increase the instantaneous luminosity by at least a factor of five, resulting in a higher muon flux rate in the forward region, which will overwhelm the current trigger system of the CMS experiment. The ME0, a gas electron multiplier detector, is proposed for the Phase-2 Muon System Upgrade to help increase the muon acceptance and to control the Level 1 muon trigger rate. To lower the probability of HV discharges, the ME0 was designed with GEM foils that are segmented on both sides. Initial testing of the ME0 showed substantial crosstalk between readout sectors. Here, we investigate, characterize, and quantify the crosstalk in the detector, and estimate the performance of the chamber as a result of this crosstalk via simulation of the detector dead time, efficiency loss, and frontend electronics response. The results of crosstalk via signals produced by applying a square voltage pulse directly on the readout strips of the detector with a pulser are summarized, and the efficacy of various mitigation strategies are presented. The crosstalk is a result of capacitive coupling between the readout strips on the readout board and between the readout strips and the bottom of GEM3. The crosstalk also generally follows a pattern where the largest magnitude of crosstalk is within the same azimuthal readout segment in the detector and in the nearest horizontal segments. The use of bypass capacitors and larger HV segments successfully reduce the crosstalk: we observe a maximum decrease of crosstalk in sectors previously experiencing crosstalk from $(1.66pm0.03)%$ to $(1.11pm0.02)%$ with all HV segments connected in parallel on the bottom of GEM3, with an HV low-pass filter, and an HV divider. These mitigation strategies slightly increase crosstalk $big(hspace{-0.1cm}lessapprox 0.4%big)$ in readout sectors farther away.
We present analytical calculations, Finite Element Analysis modeling, and physical measurements of the interstrip capacitances for different potential strip geometries and dimensions of the readout boards for the GE2/1 triple-Gas Electron Multiplier detector in the CMS muon system upgrade. The main goal of the study is to find configurations that minimize the interstrip capacitances and consequently maximize the signal-to-noise ratio for the detector. We find agreement at the 1.5--4.8% level between the two methods of calculations and on the average at the 17% level between calculations and measurements. A configuration with halved strip lengths and doubled strip widths results in a measured 27--29% reduction over the original configuration while leaving the total number of strips unchanged. We have now adopted this design modification for all eight module types of the GE2/1 detector and will produce the final detector with this new strip design.
Log in to be able to interact and post comments
comments
Fetching comments
Sign in to be able to follow your search criteria
