Upgrade of hadron endcap calorimeters CMS at LHC

We present the survey of the main tasks in upgrading the hadron endcap (HE) calorimeters of the CMS experiment at LHC. The results of the HE upgrade during the LHC Long Shutdown (2013–2014) and plans for upgrade during LHC Extended Year End Technical Stop (December 2016–May 2017) are discussed.     

The upgrade of endcap CMS muon system

The configuration and composition of the CMS muon system are presented. The paper is focused on cathode strip chambers (CSC) used as the endcap muon system detectors. The goals and objectives of the endcap muon system upgrade are formulated. The main results of works accomplished for the ME1/1 CSCs upgrade and the new ME4/2 muon station construction during the LHC Long Shutdown-1 (2013–2014) are presented. The improved performances of the endcap muon system are shown using experimental data obtained after the upgrade (Run2 data).     

Measurement of space resolution of endcap hadronic calorimeter CMS using beam testing of CMS HCAL prototype in 2003

Results of measurement of space resolution of the hadronic endcap calorimeter (HE) CMS based on data obtained at testing HE prototype on a pion beam at CERN in 2003 are presented. Polar angle resolution as a function of polar angle and pion energy are determined. Coefficients for transition from the shower center to particle coordinates are calculated.     

Influence of magnetic field on scintillators brightening in hadron calorimeters of endcap parts of Compact Muon Solenoid plant of Large Hadron Collider

The influence of magnetic field on brightening of scintillators of endcap hadron calorimeters of the Compact Muon Solenoid (CMS) plant of the Large Hadron Collider (LHC) has been investigated. Experimental studies were performed with cosmic ray muons in real configuration of the CMS plant with magnetic field (B = 3.8 T) turned on and off. It was shown that the magnetic field increases the brightening of scintillators by 8.4%.     

Understanding the performance of CMS calorimeter

The performance of the CMS hadron calorimeter is studied using test beam facilities at CERN. Two wedges of brass-scintillator calorimeter are exposed to negative and positive beams with momenta between 3 and 300 GeV/c. Light produced in the scintillators are collected using wavelength shifting fibres and read out using hybrid photodiodes. Each of the wedges has 17 layers of scintillators. In one of these wedges signal from all 17 layers are grouped together while in the other each layer is read out separately. The response, energy resolution, longitudinal and lateral shower profiles are measured. on behalf of the CMS Collaboration     

Status of the endcap BGO calorimeter of the CMD-3 detector

The electromagnetic endcap BGO calorimeter of the CMD-3 detector is ready for experiments at the new e ⁺ e ^? collider VEPP-2000. Light readout is performed by silicon photodiodes. A thermalcontrol system that is able to maintain the calorimeter temperature at a level of 12 ±1°C was designed and manufactured. All blocks of the endcap calorimeter are assembled, tested, and prepared for installing at the detector.     

Detector Effects on the Response of a Highly Granular Hadron Calorimeter to Single Hadrons

In the detectors currently being developed for experiments on the next-generation lepton colliders, highly granular calorimeters are to be used. In particular, the hadron calorimeter is planned to be assembled from scintillation cells with direct readout of light by silicon photomultipliers. According to the results of experimental measurements of the light collection in a cell developed for the CALICE prototype hadron calorimeter, when detecting minimum ionizing particles, an estimate of the detector effects was obtained. The detector effect on the resolution of the ILD hadron calorimeter was studied by modeling the response of the detector to single neutral kaons. It was shown that the contribution of experimentally measured detector effects to the resolution for single particles is on the order of 0.5–1% in the range of hadron energy of 5–60 GeV.     

Design, performance, and calibration of CMS hadron-barrel calorimeter wedges

Extensive measurements have been made with pions, electrons and muons on four production wedges of the compact muon solenoid (CMS) hadron barrel (HB) calorimeter in the H2 beam line at CERN with particle momenta varying from 20 to 300 GeV/c. The time structure of the events was measured with the full chain of preproduction front-end electronics running at 34 MHz. Moving-wire radioactive source data were also collected for all scintillator layers in the HB. The energy dependent time slewing effect was measured and tuned for optimal performance.     

The use of Higgs boson production process for optimization of hadron calorimeter segmentation

A new approach to the determination of the optimum transverse segmentation of the hadron calorimeter using the Higgs boson production process via the vector boson fusion mechanism is considered. Monte Carlo simulation results are presented for the hadron calorimeter which will be installed after the modernization of 2023 in the Compact Muon Superdetector collaboration at the Large Hadron Collider of the CERN.     

π-μ IDENTIFICATION AND HADRON CALORIMETER ANALYSIS OF ALEPH EXPERIMENT WITH MULTIVARIATER STATISTICS METHOD

In this paper π-μ identification of the hadron calorimeter prototype and the real hadron calorimeter with muon detector of ALEPH experiment on LEP is investigated by using discriminant analysis method of multivariate statistics.     

ME1/1 cathode strip chambers for CMS experiment

The ME1/1 cathode strip chambers are the part of the CMS endcap muon system. They were designed and produced in Dubna. The chambers have been installed in the detector and commissioning has been completed. This paper describes chamber readout electronics and presents the results of the tests with cosmicray muons. The article is published in the original.     

Electromagnetic secondaries and punch-through effects in the CMS ME1/1

The aim of this work is to estimate the shower leakage from the CMS Endcap Hadron calorimeter (HE) due to electromagnetic secondaries and punch-through in the region of the ME1/1 Forward Muon Station. Two configurations are considered: with and without the CMS Endcap Electromagnetic calorimeter (EE). The experimental data have been taken during the combined beam test of CMS subdetectors (HE, ME, RPC, DT) at the CERN H2 beam facility in 2004. Serial CSC chambers (ready for installation in CMS) fully equipped with readout electronics have been exposed. Simulation of a beam test setup has been performed using the GEANT4-based simulation software package OSCAR. The text was submitted by the authors in English.     

Forward hadron calorimeter for measurements of projectile spectators in heavy-ion experiment

The construction and performance of a modular hadron calorimeter for NA61 experiment at CERN are described. The calorimeter consists of individual lead/scintillator sandwich modules with the sampling satisfying the compensating condition. The light from the individual scintillator tiles is captured and transported with the WLS-fibers embedded in the scintillator grooves. The light readout is done by avalanche micro-pixel photodiodes. The construction ensures a fine transverse granulation of the calorimeter and a longitudinal segmentation of each module in 10 independent sections. The results of beam tests of the calorimeter prototype are presented.     

A Monte Carlo simulation approach to glass-resistive plate chamber response to e+/e-

Resistive plate chambers (RPCs) have been chosen as a part of the muon trigger detectors in the CMS experiment. They are used both in the endcaps and in the barrel regions, and they have to work in an extreme radiation background. Test of glass-RPC detectors have been performed in order to investigate their performance in such situations. In the present work, the simulation response of glass-RPCs exposed to positrons/electrons is evaluated. As expected a lower sensitivity of glass-RPC with respect to the bakelite-RPC has been observed since the glass density is higher and therefore a lower fraction of electrons can reach the gas gap. The obtained results were applied to CMS/RPC endcap and barrel regions, and their respective sensitivities to those particles are reported together with hit rates.     

Study of the Response Uniformity of Scintillator Tiles for Highly Granular Calorimeters

A modern trend in calorimetry is an increase in calorimeter granularity. A high-granularity hadron calorimeter assembled from scintillator tiles with signal readout by silicon photomultipliers is developed and tested by the CALICE collaboration. The uniformity of the tile response to minimum ionizing particles is studied, and these experimental measurements are compared with simulation based on the Geant4 package.     

Prototype of time digitizing system for BESⅢ endcap TOF upgrade

The prototype of a time digitizing system for the BESⅢ endcap TOF (ETOF) upgrade is introduced in this paper. The ETOF readout electronics has a distributed architecture. Hit signals from the multi-gap resistive plate chamber (MRPC) are signaled as LVDS by front-end electronics (FEE) and are then sent to the back-end time digitizing system via long shield differential twisted pair cables. The ETOF digitizing system consists of two VME crates, each of which contains modules for time digitization, clock, trigger, fast control, etc. The time digitizing module (TDIG) of this prototype can support up to 72 electrical channels for hit information measurement. The fast control (FCTL) module can operate in barrel or endcap mode. The barrel FCTL fans out fast control signals from the trigger system to the endcap FCTLs, merges data from the endcaps and then transfers to the trigger system. Without modifying the barrel TOF (BTOF) structure, this time digitizing architecture benefits from improved ETOF performance without degrading the BTOF performance. Lab experiments show that the time resolution of this digitizing system can be lower than 20 ps, and the data throughput to the DAQ can be about 92 Mbps. Beam experiments show that the total time resolution can be lower than 45 ps.     

Prototype of time digitizing system for BESⅢ endcap TOF upgrade

The prototype of a time digitizing system for the BESⅢ endcap TOF (ETOF) upgrade is introduced in this paper. The ETOF readout electronics has a distributed architecture. Hit signals from the multi-gap resistive plate chamber (MRPC) are signaled as LVDS by front-end electronics (FEE) and are then sent to the back-end time digitizing system via long shield differential twisted pair cables. The ETOF digitizing system consists of two VME crates, each of which contains modules for time digitization, clock, trigger, fast control, etc. The time digitizing module (TDIG) of this prototype can support up to 72 electrical channels for hit information measurement. The fast control (FCTL) module can operate in barrel or endcap mode. The barrel FCTL fans out fast control signals from the trigger system to the endcap FCTLs, merges data from the endcaps and then transfers to the trigger system. Without modifying the barrel TOF (BTOF) structure, this time digitizing architecture benefits from improved ETOF performance without degrading the BTOF performance. Lab experiments show that the time resolution of this digitizing system can be lower than 20 ps, and the data throughput to the DAQ can be about 92 Mbps. Beam experiments show that the total time resolution can be lower than 45 ps.     

在羊八井设置KASCADE强子量能器研究宇宙线膝区成分

预期在高海拔测量宇宙线空气簇射（AS）轴心中的高能强子成分能提供对宇宙线膝区成分灵敏的一些新的AS观测量。 假定在羊八井ARGO阵列的中央设置一台类似于KASCADE所使用的强子量能器, 记录AS轴心区的高能强子, 模拟计算分析表明, 采用适当的事例选择条件, 能在有效运行1—2 a的观测数据中, 选出有合理大小的、 初能在膝区的、 由AS轴心区高能强子组成的事例样本, 并给出对膝区成分灵敏的许多新观测量的分布。 It is shown that measuring the high energy hadrons in air shower cores at high altitudes (like Yangbajing) can provide some new observables which are sensitive to the cosmic ray composition at the knee region. Assuming a hadron calorimeter (like KASCADE calorimeter) is set up at the center of ARGO array, the event selection conditions are studied for that the primary energies of the selected events range just around the knee. The sample has a reasonable size for 1—2 years’ exposure and a number of observables are shown to be sensitive to the composition.     

The Multi-Purpose Detector for NICA heavy-Ion Collider at JINR

The Multi-Purpose Detector (MPD) is designed to study heavy-ion collisions at the Nuclotron-based heavy Ion Collider fAcility (NICA) at JINR, Dubna. Its main components located inside a superconducting solenoid are a tracking system composed of a silicon microstrip vertex detector followed by a large volume time-projection chamber, a time-of-flight system for particle identification and a barrel electromagnetic calorimeter. A zero degree hadron calorimeter is designed specifically to measure the energy of spectators. In this paper, all parts of the apparatus are described and their tracking and particle identification parameters are discussed in some detail.     

CALICE scintillator hadron calorimeter prototype commissioning and calibration

First experience with construction and positron beam tests of a scintillator tile hadron calorimeter are discussed. Participating Institutes are DESY (FLC) Hamburg, ITEP, LPI, MEPHI Moscow, Institute of Physics AS CR, IPNP of Charles University, Prague within the CALICE Collaboration.