159 research outputs found

    Клиническое наблюдение пациента с внебольничной пневмонией, вызванной Legionellа pneumophila

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    A clinical case of community-acquired pneumonia (CAP) caused by Legionellа pneumophila is described in the article. A 37-year-old male, a worker of a nuclear power station, was admitted with dry cough, dyspnea on light exertion, and fever. The disease onset was acute; the patient had been unsuccessfully treated with b-lactam antibiotics for 5 days before the admission. Two weeks before the disease onset, he had been to a neighbor region by business and stayed in a hotel. Non-severe bilateral CAP caused by Legionella was diagnosed using standard methods including Legionella rapid urine antigen test. Pneumonia was complicated by pleural exudate and moderate respiratory failure (class III according to PORT scale). Clinical particularities included diarrhea in the first day of the disease, elevated hepatic enzyme levels in blood, elevated blood urea, and hepatomegaly. Adequate specific therapy with levofloxacin and supplemental oxygen resulted in slow resolving of physical signs of pneumonia and pleuritis during 14 days with complete resolution of clinical symptoms and laboratory abnormalities and long-term maintenance of pulmonary infiltration.Представлено описание клинического случая внебольничной пневмонии (ВП), вызванной Legionellа pneumophila. Мужчина 37 лет, работник атомной электростанции, госпитализирован с жалобами на сухой кашель, одышку при незначительной физической нагрузке, лихорадку. Заболел остро, амбулаторно в течение 5 дней получал β-лактамные антибиотики – без эффекта; 2 нед. назад находился в соседнем регионе в командировке, где проживал в гостинице. При лабораторном и инструментальном обследовании, включавшем стандартные методы и экспресс-тест на наличие легионеллезной антигенурии, диагностирована двусторонняя легионеллезная ВП нетяжелого течения, осложнившаяся развитием экссудативного плеврита и дыхательной недостаточности II степени (III класс риска по шкале PORT). Особенности клинической картины: наличие у пациента в первые сутки заболевания диареи, повышение уровня аспартатаминотрансферазы, γ-глутамилтрансферазы, мочевины при лабораторном, гепатомегалия – при инструментальном исследовании. На фоне адекватной этиотропной терапии (левофлоксацин) и оксигенотерапии отмечалось медленное разрешение аускультативных и перкуторных изменений, обусловленных пневмонией и плевритом (14 дней) при практически полном регрессе клинических симптомов и лабораторных признаков, длительное сохранение пневмонической инфильтрации

    Development and performance of Triple-GEM detectors for the upgrade of the muon system of the CMS experiment

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    The CMS Collaboration is evaluating GEM detectors for the upgrade of the muon system. This contribution will focus on the R&D performed on chambers design features and will discuss the performance of the upgraded detector

    Overview of large area triple-GEM detectors for the CMS forward muon upgrade

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    In order to cope with the harsh environment expected from the high luminosity LHC, the CMS forward muon system requires an upgrade. The two main challenges expected in this environment are an increase in the trigger rate and increased background radiation leading to a potential degradation of the particle ID performance. Additionally, upgrades to other subdetectors of CMS allow for extended coverage for particle tracking, and adding muon system coverage to this region will further enhance the performance of CMS

    A novel application of Fiber Bragg Grating (FBG) sensors in MPGD

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    We present a novel application of Fiber Bragg Grating (FBG) sensors in the construction and characterisation of Micro Pattern Gaseous Detector (MPGD), with particular attention to the realisation of the largest triple (Gas electron Multiplier) GEM chambers so far operated, the GE1/1 chambers of the CMS experiment at LHC. The GE1/1 CMS project consists of 144 GEM chambers of about 0.5 m2 active area each, employing three GEM foils per chamber, to be installed in the forward region of the CMS endcap during the long shutdown of LHC in 2108-2019. The large active area of each GE1/1 chamber consists of GEM foils that are mechanically stretched in order to secure their flatness and the consequent uniform performance of the GE1/1 chamber across its whole active surface. So far FBGs have been used in high energy physics mainly as high precision positioning and re-positioning sensors and as low cost, easy to mount, low space consuming temperature sensors. FBGs are also commonly used for very precise strain measurements in material studies. In this work we present a novel use of FBGs as flatness and mechanical tensioning sensors applied to the wide GEM foils of the GE1/1 chambers. A network of FBG sensors have been used to determine the optimal mechanical tension applied and to characterise the mechanical tension that should be applied to the foils. We discuss the results of the test done on a full-sized GE1/1 final prototype, the studies done to fully characterise the GEM material, how this information was used to define a standard assembly procedure and possible future developments.Comment: 4 pages, 4 figures, presented by Luigi Benussi at MPGD 2015 (Trieste, Italy). arXiv admin note: text overlap with arXiv:1512.0848

    Charged particle detection performance of Gas Electron Multiplier (GEM) detectors for the upgrade of CMS endcap muon system at the CERN LHC

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    The Compact Muon Solenoid (CMS) detector is one of the two general-purpose detectors at the CERN LHC. LHC will provide exceptional high instantaneous and integrated luminosity after second long shutdown. The forward region |η| ≥ 1:5 of CMS detector will face extremely high particle rates in tens of kHz/cm2 and hence it will affect the momentum resolution, efficiency and longevity of the muon detectors. Here, η is pseudorapidity defined as η = -ln(tan(θ/2)), where θ is the polar angle measured from z-axis. To overcome these issues the CMSGEM collaboration has proposed to install new large size rate capable Triple Gas Electron Multiplier (GEM) detectors in the forward region of CMS muon system. The first set of Triple GEM detectors will be installed in the GE1/1 region (1:6 <; |η| <; 2.2) of the muon endcap during the long shutdown 2 (LS2) of the LHC. Towards this goal, full size CMS Triple GEM detectors have been fabricated and tested at the CERN SPS, H2 and H4 test beam facility. The GEM detectors were operated with two gas mixtures: Ar/CO2 (70/30) and Ar/CO2/CF4 (45/15/40). In 2014, good quality data was collected during test beam campaigns. In this paper, the performance of the detectors is summarized based on their tracking efficiency and time resolution

    Design of a constant fraction discriminator for the VFAT3 front-end ASIC of the CMS GEM detector

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    In this work the design of a constant fraction discriminator (CFD) to be used in the VFAT3 chip for the read-out of the triple-GEM detectors of the CMS experiment, is described. A prototype chip containing 8 CFDs was implemented using 130 nm CMOS technology and test results are shown. © CERN 2016

    Quality control for the first large areas of triple-GEM chambers for the CMS endcaps

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    The CMS Collaboration plans to equip the very forward muon system with triple-GEM detectors that can withstand the environment of the High-Luminosity LHC.This project is at the final stages of R&D and moving to production. A large area of several 100 m 2 are to be instrumented with GEM detectors which will be produced in six different sites around the world. A common construction and quality control procedure is required to ensure the performance of each detector.The quality control steps will include optical inspection,cleaning and baking of all materials and parts used to build the detector,leakage current tests of the GEM foils,high voltage tests,gas leak tests of the chambers and monitoring pressures time,gain calibration to know the optimal operation region of the detector,gain uniformity tests, and studying the efficiency,noise and tracking performance of the detectors in a cosmic stand using scintillator

    Performance of the CMS Cathode Strip Chambers with Cosmic Rays

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    The Cathode Strip Chambers (CSCs) constitute the primary muon tracking device in the CMS endcaps. Their performance has been evaluated using data taken during a cosmic ray run in fall 2008. Measured noise levels are low, with the number of noisy channels well below 1%. Coordinate resolution was measured for all types of chambers, and fall in the range 47 microns to 243 microns. The efficiencies for local charged track triggers, for hit and for segments reconstruction were measured, and are above 99%. The timing resolution per layer is approximately 5 ns

    Performance and Operation of the CMS Electromagnetic Calorimeter

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    The operation and general performance of the CMS electromagnetic calorimeter using cosmic-ray muons are described. These muons were recorded after the closure of the CMS detector in late 2008. The calorimeter is made of lead tungstate crystals and the overall status of the 75848 channels corresponding to the barrel and endcap detectors is reported. The stability of crucial operational parameters, such as high voltage, temperature and electronic noise, is summarised and the performance of the light monitoring system is presented

    Efficiency of Finding Muon Track Trigger Primitives in CMS Cathode Strip Chambers

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    In the CMS Experiment, muon detection in the forward direction is accomplished by cathode strip chambers~(CSC). These detectors identify muons, provide a fast muon trigger, and give a precise measurement of the muon trajectory. There are 468 six-plane CSCs in the system. The efficiency of finding muon trigger primitives (muon track segments) was studied using~36 CMS CSCs and cosmic ray muons during the Magnet Test and Cosmic Challenge~(MTCC) exercise conducted by the~CMS experiment in~2006. In contrast to earlier studies that used muon beams to illuminate a very small chamber area (< ⁣0.01< \! 0.01~m2^2), results presented in this paper were obtained by many installed CSCs operating {\em in situ} over an area of  ⁣23\approx \! 23~m2^2 as a part of the~CMS experiment. The efficiency of finding 2-dimensional trigger primitives within 6-layer chambers was found to be~99.93±0.03%99.93 \pm 0.03\%. These segments, found by the CSC electronics within 800800~ns after the passing of a muon through the chambers, are the input information for the Level-1 muon trigger and, also, are a necessary condition for chambers to be read out by the Data Acquisition System
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