CMS reconstruction improvement for the muon tracking by the RPC chambers
Min Suk Kim
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Presented by Minsuk Kim at the XI workshop on Resistive Plate Chambers and Related Detectors - RPC2012, INFN Laboratori Nazionali di Frascati Italy, February 5-10, 2012
The contribution of Resistive Plate Chamber (RPC) to muon reconstruction in CMS has been studied on a sample of muons collected in proton-proton collisions at sqrt(s) = 7 TeV at the LHC in 2011. Muon reconstruction is performed using the all-silicon inner tracker and with up to four stations of gas-ionization muon detectors. Drift Tubes and Cathode Strip Chambers detect muons in the barrel and endcap regions, respectively, and are complemented by the RPC system. Measured distributions of reconstructed hits in the RPCs crossed by muons from Z decays with a transverse momentum pT above 20 GeV/c are well reproduced by the Monte Carlo simulation. From the samples of J/psi and Z events, the efficiencies for muons with and without the inclusion of the RPC hits in the muon track reconstruction are measured and compared with the simulation. Using RPC information in track reconstruction improves up to about 3% of offline reconstruction efficiency for the muons in the region of pT above 7 GeV/c, in good agreement with simulation.
Study of Performance of Bakelite Resistive Plate Chamber (RPC)
电阻板室（RPC）是一种具有良好时间和位置分辨率的气体探测器。VECC参与了本土开发的胶木RPC的研发。在印度开发的酚醛树脂RPC的最大尺寸是100 cm $\times$ 100 cm。本文介绍了胶木样品的测试结果以及在VECC制造的胶木RPC（30 cm $\times$ 30 cm $\times$ 0.2 cm）的宇宙射线测试结果。还讨论了研制大尺寸（240 cm $\times$ 120 cm $\times$ 0.2 cm）酚醛树脂RPC所采取的步骤。
The CMS experiment collected around 150 fb$^{-1}$ of proton-proton collision data at $\sqrt{s}$ = 13 TeV during the Run-2 data taking period of LHC. The CMS RPC system provided redundant information for robust muon triggering, reconstruction and identification. To ensure stable data taking, the CMS RPC collaboration has performed detector operation, calibration and performance studies. After the end of Run-2, it was started the second LHC long shutdown period (LS2), an important opportunity for maintenance and preparation for the next data taking period (Run-3) and the installation of services…
Resistive Plate Chambers have a very important role for muon triggering both in the barrel and in the endcap regions of the CMS experiment at the Large Hadron Collider (LHC). In order to optimize their performance, it is of primary importance to tune the electronic threshold of the front-end boards reading the signals from these detectors. In this paper we present the results of a study aimed to evaluate the effects on the RPC efficiency, cluster size and detector intrinsic noise rate, of variations of the electronics threshold voltage.
A numerical model based on Finite Element Method (FEM) has been developed to simulate the electrical properties of RPC utilizing the law of current conservation. It has been used to systematically investigate the effect of the electrical as well as the geometrical parameters of the device components on the potential distribution and field configuration which govern the RPC performance. The numerical model has been validated by comparing the dark current and electric field with those produced by another mathematical model based on surface currents. The efficacy of the present model has been dem…
The reduction of the average charge per count in the gas along with the capability to discriminate very small signals from noise can allow an efficient and long-term Resistive Plate Chamber detector operation in high radiation background environment. This goal has been reached during the R&D program of the BIS78 upgrade project of the ATLAS detector at LHC through the deep integration of a fast (100 ps peaking time) and sensitive (as small as 100 `V threshold) Front- End electronics (FE) with a very large size detector structure. This innovative RPC integration concept pivots on a newly concei…
The CMS Resistive Plate Chamber (RPC) system has been certified for 10 years of LHC operation. In the next years, during the High luminosity LHC (HL-LHC) phase, the LHC instantaneous luminosity will increase to a factor five more than the existing LHC luminosity. This will subject the present CMS RPC system to background rates and operating conditions much higher with respect to those for which the detectors have been designed. Those conditions could affect the detector properties and introduce nonrecoverable aging effects. A dedicated longevity test is set up in the CERN Gamma Irradiation Fac…
ALICE μ子触发器目前由一个探测器产生，该探测器目前由72个以最大雪崩模式运行的胶木单间隙电阻板室组成，排列在四个5.5x6.5平方米的探测平面上。为了满足即将从2021年开始的LHC高亮度运行的要求，其中ALICE将以连续模式读出，μ子触发器将成为μ子标识符，并将进行重大升级。在当前设置中，来自约21k条的信号由2400个非放大前端（FEE）卡区分，其阈值由外部模拟电压提供（每个腔室侧一个）。所有这些卡将被配备有前置放大级的鉴别器所取代，这将允许降低探测器的操作高压，从而延长其寿命。此外，它们的参考阈值将通过无线（和每个腔室侧链接的I2C）传递，允许在单个卡级别调整值。此外，24个暴露最多的室将被更换为新的，配备高质量（即更光滑的表面）电木层压板。报告了在测试台和探测器上使用的新FEE卡以及在新RPC室（带有宇宙射线）上进行的测试。
The CMS RPC gas gain monitoring system: an overview and preliminary results
介绍了INFN（Istituto Nazionale di Fisica Nucleare）Frascati实验室研制的CMS RPC气体增益监测（GGM）系统的现状，GGM系统是一个基于小型RPC探测器的宇宙线望远镜，其工作气体与CMS RPC系统相同。GGM增益和效率被连续在线监测，从而提供对工作点条件的任何变化的快速和准确的确定。介绍了GGM的施工细节和调试的初步结果。
The expected radiation background in the CMS RPC system has been studied using the MC prediction with the CMS FLUKA simulation of the detector and the cavern. The MC geometry used in the analysis describes very accurately the present RPC system but still does not include the complete description of the RPC upgrade region with pseudorapidity $1.9 < \lvert η\rvert < 2.4$. Present results will be updated with the final geometry description, once it is available. The radiation background has been studied in terms of expected particle rates, absorbed dose and fluence. Two High Luminosity LHC (HL-LH…
The intrinsic rate capability and the ageing properties of the Resistive Plate Chambers are closely related to the electrodes material and to the front-end electronics threshold. The development of a low noise pre-amplifier led us to improve the intrinsic rate capability of High Pressure Laminate (bakelite) up to $\sim10\;kHz/cm^2$, nevertheless the effective rate is significantly limited by electrodes ageing. To further improve the effective rate capability new materials are investigated. A Resistive Plate Chamber with crystalline semi-insulating Gallium Arsenide electrodes has been character…
Resistive Plate Chamber Detector Construction and Certification: State-of-the-Art Facilities at the Max Planck Institute for Physics, in Partnership with Industrial Partners
The Resistive Plate Chamber is a widely used detector in high energy physics. The operating potential of this chamber is determined by the optimisation of the efficiency and noise rate of the device. This optimisation is based on the assumption that the performance of the device over the whole surface area is uniform. The INO-ICAL experiment is going to use $\sim$ 30000 RPC of size $\sim$2\,m$\times$2\,m. All the RPC will have to pass a minimum quality assurance criteria, but may not be able to maintain a good uniformity over the whole surface area, particularly for the whole running period of…
The mitigation of human-induced climate change is of crucial importance for the sustainability of humankind. For this aim the RPC community has exerted considerable effort over the last decade to reduce the emission of greenhouse gases from our detectors. These included searching for new eco-friendly gases, implementing recovery and/or recirculation systems, improving gastightness and using new materials and approaches in detector conception and operation for the reduction of gas flow rates. Along this line of work, we present here an RPC architecture aimed at a dramatic reduction of gas use i…
During Phase-2 of the LHC, known as the High Luminosity LHC (HL-LHC), the accelerator will increase its instantaneous luminosity to 5 $\times$ 10$^{34}$ cm$^{-2}$ s$^{-1}$, delivering an integrated luminosity of 3000 fb$^{-1}$ over 10 years of operation starting from 2027. In view of the HL-LHC, the CMS muon system will be upgraded to sustain efficient muon triggering and reconstruction performance. Resistive Plate Chambers (RPCs) serve as dedicated detectors for muon triggering due to their excellent timing resolution, and will extend $|η|$ (pseudorapidity) up to a region of 2.4. Before Long …
